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Don't jump on me, I need this vehicle for my business.

2004 Ford F150 with heavy duty payload package. 4.10gears/5.4L engine/4X2

I drive conservatively, rarely exceed 62.5mph on highways and coast and anticipate lights/traffic. My truck is rated at 13/17 but I think that's with a regular cab and the lowest gear ratio. my truck is a supercab(800lbs.+) and has 4.1 gears as opposed to 3.31 gears. I also carry a consistent 500lbs in the bed with spikes of an additional 500lbs once a week.

regular driving gets 13mpg. I tried a fuel economy run which is my regular 50/50 city highway driving route but with a 100% commitment to maximizing my fuel economy and got a whopping 15.5mpg. I have to admit though, it was a painful experience.

my question is, concerning gearing. how much of a mileage gain will I achieve if I change the rear end gearing on my truck to the 3.31 ratio. I calculated a drop at 62.5mph from 1950 rpm to 1600 rpm. will this make a difference in real world driving or is it just maybe 1mpg, which really is not worth it on a cost/payback basis.

thanks in advance for any and all suggestions and, no, I actually do need this truck for work and yes, I would rather be driving my old crx.

Welcome, endura. Unfortunately, with a setup like yours single-digit gains will be all you'll likely see. However, rather than looking at it like only getting from 13 to 15.5 MPG, realize that this is a whopping 20% gain! You're in the mileage realm of RVs and Hummers so every little gain is going to be a big percentage.

As you guessed, I also estimate that switching the gearing would grant about 1, possibly 1.5 MPG. That might not sound like much but that would be a 10% gain! Most of us would jump at the chance to gain an additional 10% FE boost with a bolt-on mod. heh

Also be sure to pump your tires up to max sidewall pressure, or as near it as you can stand. That will help, especially with all the extra weight you carry.

Pump up the tires to max, use a ScanGauge and lots of coasting and drop your speed from 100kph to 85kph for starters... and a numerically lower axle ratio would be a big aid at any speed above 65 to 70 kph because a 4.11:1 rear axle is pretty tough on mileage.

The payloads you described don't require anything heavy duty, so you might consider getting a plain vanilla six cylinder big cab F-150 manual transmission (or maybe Ranger if size isn't a concern) for your loads. Otherwise look at your truck and see if there is a bunch of un-aerodynamic equipment like ladder racks on it that you don't really need.

The 6 cyl automatic F150 X-cab with topper, supplies and tools that I drive sometimes at work is only in the upper teens to about twenty at best, so I'm thinking you should set your goal with your current truck somewhere in the upper teens (ouch!).

Most people improve their mileage by taking a lot of baby steps. The guys above offered some good advice. Read the articles elsewhere on this site for a bunch more good suggestions. The best tool I've come across to see if my steps are in the right direction is the scan gauge that plugs into the diagnostic port under the dash and provides feedback about instantaneous and average gas mileage.

Welcome and good luck!

Changing the axle might help. Not sure why your mpg is so low. I drive a Dakota 5.2 (14/18) and the lowest road mpg I've ever gotten is 14 even hauling 800lb of rebar. Do you have a bunch of stop-and-go downtown city traffic? Is this off-road mileage? Is your tranny in good shape- full, ATF not burned, not slipping, etc... ? Do you have a hung brake (maybe from a trailer hitch)?

As for the axle, it looks like it'd be a 15-20% gain depending on operating condition.

I posted this 7-27-07.

F150 EC FX4 hypermiling
I borrowed a friend's shop truck today to pick up new bedroom furniture for my daughter's room. My wife still hasn't got off of her shopping "high" after Hybridfest.

It is a 2004 F150 4x4 FX4 extended cab with a 4 speed auto, and 4.6 V8.
I drove it 32 miles with the scangauge each way. Driving speed was 50mph.

Trip there: 23 mpg
return trip with over 500 lbs in the bed and sticking up about a foot above the cab: 22mpg

EPA: 13 City, 17 Highway, 14 combined

164% over combined there

ONLY 157% over combined loaded.

I checked the tire pressure before I took the truck back to him

Right front tire was 41.5 psi the rest were at 38psi.

Without the Scangauge, it would not have been possible to get as much MPG .

Diamond Larry, you're right! TP is critical. 1 point TP is even more important on that hog.



Throttle control/speed is a major factor and the rear end gearing in your truck makes speed even more of a factor. I used the Scangauge to watch throttle pressure and drove with rock steady throttle control. The truck is used by my friends company for mostly local errands and they get in the 10 to 11 mpg per tank range. For this trip, I ran at 50 mph max.

If your loads will permit it, a bed cover might help. Or better yet a lightweight cab-high cap.
And I agree with all of the above, particularly dropping the speed.

I need a four door truck because I drop off 3 children at school in the morning.

Also, I needed an 8foot bed and the only combination of the two was this particular truck. About once a month, I actually load over 2000lbs into this truck, so the payload capacity is being used, albeit not everyday.

The tires are at 60psi already because that's what the heavy duty package calls for.

I have a folding tonneau cover already as I organized all my tools supplies to stay withing bed height.

I used to have a 2000 nissan frontier 4 door pickup V6/auto with a camper top and a roof rack as everything didn't fit in the bed. with that combination, same general driving routine, I was getting 15mpg. Before that, when I first started, I had a 4cyl. 5 speed 1991 mazda mpv minivan that averaged 17mpg, but, freeway merging came to the point of being dangerous.

I already posed my question on some applicable truck forums but people there, not all, seem more concerned with adding gigantic tires than maximizing efficiency out of their vehicles. which is fine, that's the point of a free society.

I've scoured the net for anyone that actually did a gearing change on a truck (or any other aerodynamically challenged vehicle) and kept track of the fuel usage, couldn't find any. The best example I see of a fuel efficiency tuned truck is the GM full size hybrid pickups and those are showing 20mpg highway.

the truck is tuned, runs perfect, synthetics everywhere. The only reasonable mechanica change I can see is a gearing change but it's just not worth it for 1-1.5mpg gain, and that's probably highway only.

Also, is optimal fuel economy the lowest rpm at top gear with TQ consistently locked, regardless of throttle pressure. Is that correct?

Sorry for the rant and thanks for the advice.

Aero mods can help a lot.

It's strange, but there is actually more drag if the gate is down. ???

Covering the bed when empty is the best thing on streamlining.

I read that with an 8 foot bed, it's actually better to have the gate down. but, I'm carrying loads and don't have that option available.

I need a four door truck because I drop off 3 children at school in the morning.

With all due respect, I think this is a silly reason to have a four door. Unless your kids are of high school age, there is no reason they can't sit in the back of a two-door for a ride to/from school.

I did a little research on the F-150, and it looks like the 8-ft. bed isn't an option with the V6. With 2000lbs of weight, the V6 would do alright. How about a smaller truck with a bed extender?

When not towing, keep your RPMs as low as possible. I'm assuming you're in an automatic, so gently roll on the throttle and keep your revs under 1500. Cruise in your highest gear and lowest RPM. Predict traffic/stoplight changes and coast up to them in neutral with the engine switched off. Do not idle at lights more than 20 seconds. Limit highway speeds to 60 MPH and on-ramp RPMs to 2500 RPMs.

It sounds a bit drastic, but if you want 50% gains, you're going to have to work for it in that beast. Lots of engine-off time, lots of coasting, and lots of very slow starts. :)

And you can artifically increase your gear length. Try starting off in second gear & shifting up to the next gear just before the current gear feals comfortable. However, if you end up compensating for the difference in gears by giving more gas, it may hurt your economy.

As far as covers go, this is true and false. Go to discovery & look up myth busters or try to watch the show and it will explain the details, but it looks like the following things come into play...
Assuming the bed is empty & tailgate is up;
1. Just behind the cab, a vortex will form, like a tornado on its side. When the truck was designed, it had those in mind and adding a cover will change that vortex, usually making it smaller. That may help slighly in economy, but isn't very noticable.
2. behind the vortex, in the remainder of the bed will be dead space where air doesn't move very much. Since it isn't interacting with the air passing over the truck it doesn't represent much drag, and covering it with a cover won't help.

With the bed empty, and the gate down;
1. remains mostly the same, but the vortex is someone unstable, and everytime is changes size, speed, shape, additional drag will be created;
2. the air that was stable & unmoving can now flow out the back, and it does. This also creates interaction with the air moving around the truck & increases turbulance & drag;
1&2 combine to DECREASE full economy, however a #3 may be added to the equations
3. If the gate isn't just down, but removed, 40-100 pounds are no longer being dragged around by your truck. That will improve fuel economy.
Like the old quesiton, which is more efficent A/C or window ventilation...the answer depends on speed. As low speeds, the loss of weight from the gate being down is the primary factor & you should see an improvement in fuel economy. At high speeds, the extra drag created by the turbulance will be in control and you will probably see reduced fuel economy.

With the bed full, and the gate up;
1 & 2 become questionable. What is in the bed may change the aerodynamics to make them turbulent. In this scenerio, covering up the bed (or really the non-aerodynamic cargo) can improve fuel economy.

With the bed full, and the gate down
? too many variables; between possible turbulance, difference in weight, etc, there really isn't a single answer but same ideas apply; At highspeeds, turbulance will have more effect & at low speeds weight will have more effect. However as an addtional note, a cover combined with a down/removed tailgate can sometimes produce a nasty vortex in the rear of the truck bed that may cause small loose items to be blown out and can also reduce fuel economy.

The last thing I'll mention was the economy winner for mythbusters, a net tailgate. It should have produced similar effects to having a tailgate without the weight penalty of dragging one around. If they are strong enough to hold your stuff in the bed, they are a great idea. However it should really matter if they are a net or a solid cloth/plastic design as long as they don't do one thing...flap. Flapping indicates that turbulance is occuring & can actually allow the turbulance to occur, so make sure they are tight enough to stay mostly ridgid.

I have a few friends who are contracts and they have to carry arround all their tools in custom made boxes in the back of their truck...Usually very heavy and their economy is terrible, but its great to see somebody in that situation trying their best to increase economy. You never mentioned it, but what is the reason you are trying to improve mpg? If its either $ or green factor, making hardware changes may not be the best idea since you will have a long time recouping cost and whatever gets replaced may not be recycled completely. If you just long for great numbers, who am I to get in your way.

Best of luck!

Another thought: it seems that you are paying a heavy penalty for that once a month you have to haul 2000lb. Would it be possible to have that load delivered or handled in some other way (for example piecemeal on succeeding days if it fits into your daily route)? A trailer? If you could avoid that load on your truck, you might manage with a smaller lighter truck.

In another thread about a week ago I listed a web page that had info on wind tunnel tests done on full size trucks with 6' and 8' beds. On 8' beds a full tonneau cover was best, and it sounds like you are there already. Over on gassavers.org there is a thread for aerodynamics, and take a look at a Dodge pickup that is aero modded.

As for aero mods, do a google search on
Phil Knox pickup
or
Phil Knox Toyota

It's worth looking at.

Are your tires "highway" tread or off-road knobby things? Smoother tread design will help mpg.

re fuel economy vs rpm:

low rpm is not necessarily the best fuel economy. The lowest fuel consumption vs torque is what your looking for. Example: accelerating at 2mph/s and cranking 1600rpm is better than 1mph/s and 1000rpm.

Throttle pressure is an indirect gauge of torque. The best way to increase the fuel economy is either get a ScanGauge or check your tach and run at the lowest rpm/unit speed. This may not be the lowest rpm possible. For example, my 4th gear kicks in at 55 but its most efficient speed in 60-65 even though the rpms are higher because the rpm per mph is lower. The calc is (RPM/Speed) and you try for the lowest quotient.

Good Luck.

[QUOTE=warthog1984;45059]For example, my 4th gear kicks in at 55 but its most efficient speed in 60-65 even though the rpms are higher because the rpm per mph is lower. The calc is (RPM/Speed) and you try for the lowest quotient.QUOTE]

Thanks! Didn't know that one.

I have a few friends who are contracts and they have to carry arround all their tools in custom made boxes in the back of their truck...Usually very heavy and their economy is terrible, but its great to see somebody in that situation trying their best to increase economy. You never mentioned it, but what is the reason you are trying to improve mpg? If its either $ or green factor, making hardware changes may not be the best idea since you will have a long time recouping cost and whatever gets replaced may not be recycled completely. If you just long for great numbers, who am I to get in your way.

Best of luck!


It's my business and I am, unfortunately, stuck with this type of vehicle. I am doing this because I grew up driving small cars and I like efficiency. I had a honda crx and enjoyed driving that more than my friends mustangs/camaros. then I got a toyota echo hatchback and loved that too. This is not about money for me, I just find it personally offensive that I have to put up with 13mpg. All my friends bought the same type of vehicle but 4X4. They use the 4wheel drive maybe 2 or 3 times per year. Their mpg averages around 10/11mpg. Each 1mpg I can raise my average is only another $400/year in my pocket, which in my business is a drop in the bucket. I'm not trying to sound high and mighty, that's just how it is.

this is personal with me. If I analyze it rationally, logic has nothing to do with it.

...I am doing this because I grew up driving small cars and I like efficiency. I had a honda crx and enjoyed driving that more than my friends mustangs/camaros....

Been driving a CRX since 1985

86 CRX HF
88 CRX HF for 250,000 miles
2000 Insight (essentially a radical makover of a CRX)

re fuel economy vs rpm:

low rpm is not necessarily the best fuel economy. The lowest fuel consumption vs torque is what your looking for. Example: accelerating at 2mph/s and cranking 1600rpm is better than 1mph/s and 1000rpm.

Throttle pressure is an indirect gauge of torque. The best way to increase the fuel economy is either get a ScanGauge or check your tach and run at the lowest rpm/unit speed. This may not be the lowest rpm possible. For example, my 4th gear kicks in at 55 but its most efficient speed in 60-65 even though the rpms are higher because the rpm per mph is lower. The calc is (RPM/Speed) and you try for the lowest quotient.

Good Luck.


I'm not sure I follow. My TQ locks in 4th gear and holds consistently at 1200RPM at about 35mph. Isn't this my optimum fuel economy speed for this vehicle in its current configuration? Unless you have a CVT, how are you changing your RPM/speed equation in top gear?

I'm not sure I follow. My TQ locks in 4th gear and holds consistently at 1200RPM at about 35mph. Isn't this my optimum fuel economy speed for this vehicle in its current configuration? Unless you have a CVT, how are you changing your RPM/speed equation in top gear?

The fuel usage for a vehicle is not linear (straight). There is a threshold to maintain operation (600-1000 rpm depending on vehicle) that just keeps the ICE and powertrain running. This is "wasted" rpms/fuel.

Beyond that, fuel usage goes up linearly with rpm. However, POWER (not rpm) is what supplies the energy to overcome friction and aerodynamic drag. However, the available Power to the wheels does not go up linearly. It varies according to the "Torque Curve" because of the nature of an ICE. Thus, fuel usage and speed are not proportional.

Also, aero drag is a function of the SQUARE of the Speed, so it takes more power at higher speed to maintain cruise.

Thus, every vehicle has a series of overlapping slightly misshaped bell curves that determine the most efficient speed at each gear.

The most efficient point is each gear is the point with the lowest RPM/Speed qoutient for each gear. The most efficient overall speed is the speed with the lowest RPM/Speed quotient period. Generally one of your top 2 gears.

Going back to my truck, it turns at 1600 rpm at 55 and 1800 at 65, which means it is 5% more efficient per MILE. At 75, it turns 2300, which is 5% less efficient than 55 and 6% or 7% less efficient than 65. At 45, it turns 1325, which is less efficient than 55 but saves the acceleration gas.

Hope that helps.

.
The most efficient point is each gear is the point with the lowest RPM/Speed qoutient for each gear. The most efficient overall speed is the speed with the lowest RPM/Speed quotient period. Generally one of your top 2 gears.

Going back to my truck, it turns at 1600 rpm at 55 and 1800 at 65, which means it is 5% more efficient per MILE. At 75, it turns 2300, which is 5% less efficient than 55 and 6% or 7% less efficient than 65. At 45, it turns 1325, which is less efficient than 55 but saves the acceleration gas.

Hope that helps.

I'm a bit confused. RPM/Speed is a linear function, how does torque come in? I mean to say, if I calculate RPM/Speed for my car in fifth gear, I'll get .25 for every combination starting with 1500 RPM and going up. I'm guessing that it's the same in the other direction (lower RPMs). So how do I find the most FE friendly speed in fifth?

swap that gas truck for diesel. the ford f250/350 4x2 diesel gets around 17mpg and maybe 15mpg fully loaded( can easily handle the 2000lbs vs the struggling 5.4L)

I'm a bit confused. RPM/Speed is a linear function, how does torque come in? I mean to say, if I calculate RPM/Speed for my car in fifth gear, I'll get .25 for every combination starting with 1500 RPM and going up. I'm guessing that it's the same in the other direction (lower RPMs). So how do I find the most FE friendly speed in fifth?

Most efficient speed is influenced by engine, gearing, aerodynamics, rolling resistance (friction), mechanical friction and several other factors. The Only way to find the most FE Friendly speed is to take a Scangauge out and find the highest FE or do a test run noting the rpms and speed for your car and doing the rpm/speed calc.

In an ideal world, it would be a simple theory calc, but in reality, other factors heavily influence FE. That is why hypermiling is better for FE than steady-state driving: a car on the roadway is not a theoretically mechanically perfect machine and it experiences heavy energy losses.

Hi,

I have been reading this thread, no nothing about trucks, but.. I hope you do go ahead and try and get the best mpg possible to get out of the Beast (you can have that name-- I had a car that I named that once). Anyway, I don't know if it sounds like for economic reasons you can just sell the thing and get something else. However, I am hoping to see your mpg figures and get that "skilled hypermiler" by your name, even if it only means you are getting 17 mpg or less.


I do think a Scan gauge will help a lot. I have already paid $25 on it for my first month (that much saved in gas).



--des

swap that gas truck for diesel. the ford f250/350 4x2 diesel gets around 17mpg and maybe 15mpg fully loaded( can easily handle the 2000lbs vs the struggling 5.4L)

I researched a diesel but it's not cost effective whatsoever for my application. Loaded yes, they are very impressive vs gas motor, but for my application, which is really a light load, their benefits are very small in real world applications.

If they come out with a smaller diesel motor for a 1500 series truck, I'll be the first in line to get one.

Going back to my truck, it turns at 1600 rpm at 55 and 1800 at 65, which means it is 5% more efficient per MILE. At 75, it turns 2300, which is 5% less efficient than 55 and 6% or 7% less efficient than 65. At 45, it turns 1325, which is less efficient than 55 but saves the acceleration gas.

Hope that helps.




so on a steady state cruise, all other factors being equal, which of the above examples nets you the highest MPG?

what are your MPG numbers for those speeds?

it's a dakota, right? what's the rear end gearing?

thanks.

so on a steady state cruise, all other factors being equal, which of the above examples nets you the highest MPG?

what are your MPG numbers for those speeds?

it's a dakota, right? what's the rear end gearing?

thanks.


Steady state the 60-65 mph band is the best (lowest rpm/speed at 27.7). Exact speed depends on washed truck, drafting, etc...

Normal driving I'm getting 15.5/18 for 50/65 mph. Paying attention to FE, 17/22 without much effort (watching acceleration, A/C use).

Hauling rebar in the field, 15 or 16 mpg from the office into the field (offroad) and back.

If I Pump up the extra shocks I put in, I can haul a long ton and get 13 or 14 MPG on a 50/50 city/highway route. Don't drive it for long like that because its supposed to be a half-ton and braking takes a while.

Stock gearing, I'll check what it is. Tires are slightly oversized for offroad use.

Yeah its a Dakota Club Cab. Yeah its got a 318 (5.2L) in it. Yes, I can smoke the tires without double footing. :D

If that truck could swap engines for daily driving I'd never let it go.

BTW- if you can drive steady state and note the rpm at 5mph intervals, I can tell you which is most efficient.

BTW- if you can drive steady state and note the rpm at 5mph intervals, I can tell you which is most efficient.


1100RPM/35MPH
1200 38
1300 41
1400 44
1500 47
1600 51
1700 54
1800 57
1900 60
2000 63
2100 66
2200 70
2300 73

1100RPM/35MPH
1200 38
1300 41
1400 44
1500 47
1600 51
1700 54
1800 57
1900 60
2000 63
2100 66
2200 70
2300 73

How many gears do you have? Are these observed rpms or theoretical? Usually this would cover 3 gears and a range of mechanical and friction losses. Remember, there will be slippage and friction losses in a truck.

Remember, this is a rear gearing and a reduction gear in the tranny Also.

this is top gear RPM/SPEED. with the TQ locked. I calculated off of tire diameter/rear end ratio/top gear ratio. observed results off speedo/tach. match exactly.

example. at 60mph, I am turning exactly 1900RPM.

What does slippage and friction losses have to do with this. this is top gear(4th) with converter locked up.

Your engine rpm/vehicle speed results are linear across a 35mph range. This is physically impossible. Power transmission from the cylinders (rpm measured) to wheels (speed) is imperfect. These results violate Newton's 2nd law (KE=1/2 mv^2), Bernoulli's theorem (drag is prop. to v^2), and the nature of an ICE engine (combustion energy vs power as inertia changes and engine overspeeds flame front).

Not to mention, if this is fourth gear, what are you doing with your other 3 gears? Usually each gear covers 20-25 mph. IE, 1st 0-25; 2nd 25-45;3rd 40-55;4th 55+. If this is correct, You're probably running horribly deep gearing. No wonder your gas mileage is bad. What do you do, tow semis for a living?

Your engine rpm/vehicle speed results are linear across a 35mph range. This is physically impossible. Power transmission from the cylinders (rpm measured) to wheels (speed) is imperfect. These results violate Newton's 2nd law (KE=1/2 mv^2), Bernoulli's theorem (drag is prop. to v^2), and the nature of an ICE engine (combustion energy vs power as inertia changes and engine overspeeds flame front).

Not to mention, if this is fourth gear, what are you doing with your other 3 gears? Usually each gear covers 20-25 mph. IE, 1st 0-25; 2nd 25-45;3rd 40-55;4th 55+. If this is correct, You're probably running horribly deep gearing. No wonder your gas mileage is bad. What do you do, tow semis for a living?

Nah, since he's got the heavy duty package, I bet he has a granny first gear that doesn't get used much that is provided in case he wants to tow a backhoe around. For purposes of light duty hauling it's probably about like having a three speed.

Before you start worrying about Newton's law vis-a-vis RPM/MPH you have to realize that you can have different torque/energy output for the same RPM-MPH combination. Think about your torque and throttle position for steady-state uphill vs steady-state downhill at the same speed. It takes a lot more torque and throttle up-hill vs. down-hill. I think you over-simplified your analysis someplace.

ok, I'm officially confused.

Your engine rpm/vehicle speed results are linear across a 35mph range. This is physically impossible.

I get similar results, that is to say rpm/speed is linear across the entire range (up to 3000 RPM anyway, which is as high as I go) in fifth and fourth gear. I think this should be normal, except for any losses between engine and wheel (by losses I mean inefficiencies, which are probably not linear). These are relatively small and account for the error when reading RPM and speed from the dash... at least, that's how I see it.

If you take out inefficiencies (like the loss you get whenever you transfer the motion, in the gearbox for instance...), then RPM/Speed IS linear.

Nah, since he's got the heavy duty package, I bet he has a granny first gear that doesn't get used much that is provided in case he wants to tow a backhoe around. For purposes of light duty hauling it's probably about like having a three speed.

Before you start worrying about Newton's law vis-a-vis RPM/MPH you have to realize that you can have different torque/energy output for the same RPM-MPH combination. Think about your torque and throttle position for steady-state uphill vs steady-state downhill at the same speed. It takes a lot more torque and throttle up-hill vs. down-hill. I think you over-simplified your analysis someplace.

Well I was thinking this was all on flat ground with slow, steady acceleration.. I wasn't going to get into uphill vs. engine braking and all that jazz.

Still, having only the one gear for that big a range can't be the most efficient. Using OD would probably save some gas at the top end. Why are the rest of the gears so deep? I can buy a granny gear, but can't see why the 2nd and 3rd would be so deep. And again, Where's the OD? I haven't seen a 4speed auto on a truck yet.

warthog,
I thought you were talking what my most efficient speed is at a steady state cruise, top gear with the torque converter locked. that is the graph I gave you.

on my truck, I'm assuming that cruising at 1200rpm/mph is my most efficient cruising speed since below that rpm the torque converter hunts quite a bit and won't consistently stay locked.

so, is my theory relatively sound? the most efficient STEADY STATE cruising rpm on a modern non-carburated vehicle is the lowest point in engine speed that the vehicle can stay in top gear with the TQ locked consistently.

I did order a scangauge, BTW.
thanks.

Nah, since he's got the heavy duty package, I bet he has a granny first gear that doesn't get used much that is provided in case he wants to tow a backhoe around. For purposes of light duty hauling it's probably about like having a three speed. .


it's a 4speed automatic, and yes, you are absolutely right. with the mandatory 4.1 rear end gears this truck comes with, 4th gear is way too high for efficient cruising. it's insane to have a 5.4L V8 with a very wide and flat 365lb/ft torque curve turning almost 2000 rpm at 62.5mph. this engine can pull this truck at that speed, even with minor grades, at 1400/1500rpm without any problems. I can understand for someone who tows large loads they would need these gears, but for my application, the fact that I need a 4 door with an 8foot box pigeonholed me into a truck that is set up from the factory, no choice, to tow 10000lbs of weight.

it's a 4speed automatic, and yes, you are absolutely right. with the mandatory 4.1 rear end gears this truck comes with, 4th gear is way too high for efficient cruising. it's insane to have a 5.4L V8 with a very wide and flat 365lb/ft torque curve turning almost 2000 rpm at 62.5mph. this engine can pull this truck at that speed, even with minor grades, at 1400/1500rpm without any problems. I can understand for someone who tows large loads they would need these gears, but for my application, the fact that I need a 4 door with an 8foot box pigeonholed me into a truck that is set up from the factory, no choice, to tow 10000lbs of weight.

This might be a case where shelling out the $ to have someone drop and regear the tranny would be worth it. If you have a flat torque curve and truly don't need the full load/tow capacity, switching to taller gears (include an OD gear )might save big bucks on gas over 2 or 3 years. That would leave a granny gear, low speed, medium speed, and OD and still leave load capacity. Just be warned that pulling the tranny runs about $1000-$15000.

Also, for your truck, 35-40 depending on idle might be the best right now. Let me know what the SG says.

Your engine rpm/vehicle speed results are linear across a 35mph range. This is physically impossible.

It's not impossible. In fact, it's the only way it can be.

If a car is locked in a gear, its wheels (mph) are mechanically linked to the engine (rpm). They vary together linearly until the torque converter gets in the game (or your foot with the clutch).

If someones sees a non-linear dependence between car speed and engine rpm _while in the same gear_ it's because of a torque converter slipping (if the torque converter is locked and this still happens, then you have a _faulty_ torque converter).

I repeat: once locked in a given gear, your speed will _always_ vary linearly with engine rpm. That's what a gearbox does.

received the scangauge today. will test out different cruising speeds and see what it shows.

endura, good stuff

Before you get overloaded in all of the rolling numbers, find out what you consume idling (AC off and AC on). That's important for determining how slow you can coast while idling and still be improving your average. For instance, if you burn gas idling at the rate of 2.5 LPH and you're trying to better an average of 14 LHK, then you wouldn't want to coast much at under 20 KPH (2.5 x 100/20 = 12.5 LHK, at 15 KPH, you'll be hurting your average at 16.7 LHK) unless the engine was off.

You might also want to keep in mind, that slow acceleration can also hurt FE. I'm sure you'll notice that the only time your truck is improving its average is when it's in OD (or coasting in N). I've found that 60% LOD is better than using low loads on my short commutes (and I kept getting more and more lightfooted and expecting better and better results). Try and get into OD quick and then you can accelerate slower after that.

Keep a little log for you short commutes. That way you can gauge the effect of different strategies on standard drives like dropping off the kids.

I'm surprised by the coasting. I'm near the lake in miss and I can coast from the QEW to Lakeshore and then from there again down my street.

It's the little things... if you're cresting a hill, let the speed slide as you go up it and then you can add it back coming down.

Have fun and good luck...

1-this scangauge device is a fantastic tool.
2-I'm showing 17mpg at a steady 70mph cruise.

peak mpg seems to be what I thought. lowest rpm at which TQ locks in top gear. 28mpg at 38mph.

at a steady cruise, I tried 3rd and 4th gears to get an idea of fuel consumption increase. It's 2mpg lower in third and the revs are about 900rpm higher. which pretty much kills my plans of changing the rear end as I was looking at a 500 rpm drop which probably gives me 1mpg. not very cost effective.

certainly is an eye opener.

How many GPH or LPH at idle?

How many GPH or LPH at idle?

.42GPH, I think.

the fuel economy is about 17mpg at 60mph, and it just gets worse after that. now that I can actually see how much fuel it's consuming in real time, I am even more disgusted with this truck.
I've got the average fuel economy up to a steady 15-16mpg.
I weighed everything in the bed. it's about 1500lbs. Quite a bit more than I thought.

the fuel economy is about 17mpg at 60mph, and it just gets worse after that. now that I can actually see how much fuel it's consuming in real time, I am even more disgusted with this truck.
I've got the average fuel economy up to a steady 15-16mpg.
I weighed everything in the bed. it's about 1500lbs. Quite a bit more than I thought.

If I can offer advice. Go to a Ford dealer, take a "test drive" in a F-150 with 4 doors and a 3.31 rear axle. Out of Sight of the Dealership, plug in the SG-II and get those numbers.

I really think the difference in FE will be substantial enough to warrant regearing the tranny or rear axle (again, at $1500, you'd save that much in a year or two).

Okay so right off the bat you're up between 15 and 23%, amazing what a ScanGauge and improved skill from feedback can do. Excellent start!!!

I too would try it out on a 3.31 geared Fiso. A more expensive option would be an external OD bolted to the end of the tranny - that would kick serious butt. Leave it off when urban for easier slower 4th entry and lockup, and then out on the open road it would be engaged and slowly roll that V8 over to maximize the efficiency. You'd have to shut off the ext. OD for hills and it would mess up your odometer in your favor whenever used. Tough part is how it would affect your warranty. Okay... so it's a pipe dream while on warranty at least.

If you doing a lot of 50 KPH speed limit driving, figure out the slowest speed in which you can get the truck into 4th. Whatever increase in geaing you get will increase that speed. Too relaxed a gear and you might not be hitting 4th in the city or risking tickets doing so and this would effectively bring your overall average down.

Good work though... the 401 is pretty tolerant of people doing the limit or less through the city so you could try that if you can have an extra couple of minutes between transit points.

1-this scangauge device is a fantastic tool.
2-I'm showing 17mpg at a steady 70mph cruise.


Seems like you're becoming hooked, welcome aboard :D

As to the 17 mpg at a steady 70 mph: I haven't done 70 mph in months, and I'm sure there are people here who don't really know what 70 mph IS :D

revised figures.

taken from scangauge. all variables other than engine rpm constant. 10km distance.

60MPH/4TH GEAR/2000RPM/AVG. 18.4MPG
60MPH/3RD GEAR/2850RPM/AVG. 14.4MPG

-a change from my 4.10 to 3.55 gears drops engine by 250RPM at 60MPH.
-based on above data, reasonable to assume highway gain of approx. 1-1.5 MPG.

-not cost efficient at 50/50 city/hwy. driving/yr. at approx. 20000 Miles/yr.

Ordered a 2007 Honda Ridgeline. Loaded the same stuff from an F150 extended cab with an 8 foot box into a truck with a 5 foot box.

How is that possible you ask?

The in bed trunk is HUGE. The tailgate opens sideways so access to the bed is fantastic and there is a ton of space under the rear seats for my tools.

I wouldnt' have believed it myself but the dealership let me take one home to see if everything would fit.

Thank you Honda.

Good bye Ford.

Keep us posted on how that works. How is it rated for towing? I'm particularly interested because this winter they will be replacing the F150 I've been driving at work and I might have some influence.

Instead of the expense of changing your gears, try a plus two tire size first which would yield you about 3 mpg. For instance, if your stock tires are 265/65/R17 try a 265/75 or a 275/70 tire size. Lower rpms = improved mpg.

Also, are you running full synthetic oil like a 0W-30 blend? This could give you 1 to 2 mpg as well over stock recommended oil viscosity. Another trick I have had good results with is water wetter in your radiator lowering overall engine temp by at about 10 degrees. I live in Southwest Florida so I can run almost pure water with water wetter in the radiator. If you live in hot climate try an 80/20 mix of water/antifreeze with water wetter. Otherwise a 50/50 mix in cooler climates.

Ordered a 2007 Honda Ridgeline. Loaded the same stuff from an F150 extended cab with an 8 foot box into a truck with a 5 foot box.

How is that possible you ask?

The in bed trunk is HUGE. The tailgate opens sideways so access to the bed is fantastic and there is a ton of space under the rear seats for my tools.

I wouldnt' have believed it myself but the dealership let me take one home to see if everything would fit.

Thank you Honda.

Good bye Ford.

Way cool! Looking for Ridgeline numbers. Post away!

Also, are you running full synthetic oil like a 0W-30 blend? This could give you 1 to 2 mpg as well over stock recommended oil viscosity. Another trick I have had good results with is water wetter in your radiator lowering overall engine temp by at about 10 degrees. I live in Southwest Florida so I can run almost pure water with water wetter in the radiator. If you live in hot climate try an 80/20 mix of water/antifreeze with water wetter. Otherwise a 50/50 mix in cooler climates.

Colder is not always better ;)

I'm trying to find more ways to keep the temps higher as we speak.

Do you have a 195 degree thermostat in your truck?
Next time you need tires, go for the ones with the best rolling resistance.

this thread proves the point that all cars should have iFCDs - well done with the hypermiling !

please post a review on the ridgeline truck, i heard it sucks for towing. Wouldn't the underpowered 3.5L be bad for towing and result poorer mpg than a 4.5L V8 that can be in its efficent powerband without being overloaded?

15.5 mpg on the first tank.

-no load, hibernating until march.
-50% short trips, cold weather. truck barely warmed up before turning off.
-25% cruise at 65mph
-25%cruise at 80mph.


-my 1992 acura legend got 15mpg with the above mentioned driving pattern.
-1994 accord got 17mpg.
-don't have a direct comparison with the F150 for this exact pattern, however, best ever on it, lightly loaded and majority highway at 60-65 mph + drafting was 15.5mpg.

ok, update on the ridgeline.

same loads, same general driving patterns, same driver, etc.,

f150 was getting 13-14mpg average.

ridgeline is getting 17-18mpg average.


thank you honda.

I just joined today and am very pleased to see this thread. I bought a Scanguage for my boyfriend for his birthday to help him out with his '02 Ford F150 supercab and I'll send him right to this site when he gets it. Thanks so much for sharing all your knowledge.