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So my commute right now is a 10 mile trip from my house to the Park & Ride, where I then ride the bus for an hour with homeless people and regular people that don't know that soap is require for showers to work properly.

Anyways, right now the majority of the 10 miles is on a freeway. I've been doing 70mph to 55mph glides on it, but I really notice how quickly the car slows down in the wind. Scangauge on average has been telling me 28mpg even on the trip there.

So I'm going to try taking the frontage roads instead tomorrow. I leave the house at 10am so there isn't much traffic on the roads, but there is enough on the interstate to where I can't go lower than 55mph. On the frontage roads I should be able to do a 60mph to 45mph glide with no problems. Plus my glides should be longer since there is a lot less wind resistance. The only problem I see is possibly getting stuck at 1 or 2 lights. I can shut off my car then but scangauge still reads fuel usage.

I'll report back here tomorrow and let everyone know how much better or worse it is.

Hi Bomber991:

___Frontage roads with slower speed P&G’s are the bomb! Literally :D

___Good Luck

___Wayne

If you lower you pulses from 60-45 down to 50 to 40 I would bet you could do even better.

Yeah, so it's completely not worth it. I get stuck at every single light, and traffic is still pretty heavy. Makes no sense to leave 15 minutes earlier than normal for a 20 minute trip. I don't think my numbers were too high cause there wasn't much coasting either. I couldn't really tell though cause the sg still counts fuel usage at all the lights even with the car off, but it said I was at 25.7mpg.

Hey, at least you tried. I've tried dozens of routes and sometimes you get a few flops before you get a good one. I like to break out google maps and piece together the most direct surface-roads path as a starting point and systematically find work-arounds for the really bad bits. The winner is the path that results in the smallest total fuel burned, which isn't always the highest FE. (Depends on the relative distances.)

Stick with it! I was able to get a 29 MPG tank out of the STi this past summer before I even knew what I was doing.

The year before I managed a 26.x tank on a huge highway trip in 95° weather with AC on. (Pre hypermiling days).

I still haven't figured out how to get the most out of the STi, the usual techniques never seemed to work the way I expected.

I have had a little experience on frontage roads. There is one in particular between Wadsworth, IL and Oak Creek, WI...:D

I'd venture that a flat 55 mph steady state cruise will yield way better results on the highway than a 70-55 P&G routine. Much less work with a slightly lower average speed...

Assume average speed with P&G is (70+55)/2 = 62.5 (probably lower due to faster speed reduction at high speed)

10 miles at 62.5 mph = .16 hour = 9 min 36 seconds

10 miles at 55 mph = .181818... hour = 10 min 55 seconds

1 minute 20 seconds saved with the P&G routine. I'd guess you're taking 5-6 mpg off your potential by doing it also.

I'll leave the rest of the math (fuel savings) to you to find out if it's worth it. :)

High speed P&G just isn't what most would hope for, as the aero makes you throw a lot away. Now if you have some nice hills, as I do on my commute, DWL up and FAS down while keeping average speed close to 55 is the winner all day long. Easy 100mpg+ in an Insight...

Ben, what you are saying definitely works in the Insight...

HOWEVER...

For my Elantra steady state cruising at 55mph on flat land nets me about 42mpg. When I drove it to Milwaukee over some VERY hilly terrain with BIG hills I used a high speed P&G routine with NICE-ON for the glides (purely because of ECU reboot times throwing the SG way off at the high rates of slowdown at those velocities) with an average speed of 67mph :o I know that is really high but I did want to get there in a reasonable length of time... The result was 51.3mpg -- over 366mi or so. I duplicated this on my drive back and kept the tank at that level.

If you keep an eye on the trip mpg and push for improvement on every single cycle of P&G, you can pull better numbers than steady state. You have to be ultra dedicated to do it, though...

IF the lights can be timed, you could do better. If the lights can't be timed you will do worse. Learning about the lights can take some time. I think it took me a good month or two to learn how to time the lights on my current commute. I do pretty well and going to work it is not at all uncommon for me to miss every single light (or at least stop at only 1-2 out of 15). There are a couple extra the other way and I can never do it, but I still only stop average of 3 times. Timing the lights is the key. If they aren't timeable, and this is possible then you will make worse mileage, even if you turn the gas off at the lights. Turnign the car on and off, and the rev up will steal your mileage.

--desx

Well I just looked it up on google maps to see how long the actual freeway portion of the trip is, and it's 7 of the 10 miles. I can get the scanguage to read about 32 to 36 mpg and it'll hold that at about 58mph. Though more often than not it's at 32 and not 36.

On the way back home tonight I tried doing 60 to 55mph glide some of the way since that range seems to last the longest. So lets assume the glide is 2x longer than the pulse, it's probably more like 3x or maybe even 4x longer, or maybe even shorter at 1.5x as long. Anyways, if I went 1 mile accelerating at 15mpg, and then coasted for 2 miles at 150mpg, (yep much larger than normal but it maintains the 2 to 1 ratio). It would come out to 1/15+2/150 gallons of gas used over 3 miles for 37.5mpg. So it would seem p&g is still slightly higher.

Anyways for tonight I ended up with 29.2mpg when pulling into the driveway.

I guess Wednesday I'll try doing just 60 to 55mph glide instead of 70 to 55mph glide on the freeway and report on that. And then maybe next Monday I'll try the steady driving at 55mph and see how well that works.

Good luck, I usually do a 45 35 p&g, seems to work out well.

When using the highway between Wayne's house and and the MiHG meeting in Oak Creek, WI, the FE is good for 70-75 in my Prius. There was a time back in August(?) when we took the frontage roads and pulled into the meeting(~38 miles) with 99.4 showing on the SG2. I had just over 100 ~3 blocks from the meeting but I couldn't hang onto it.:(

I tried the 60 to 55 glide today on the way there. Ended up with 30.8mpg and the tanks at 29.2 now, 110 miles on it, and still about a mm above the 3/4 mark.

Got stuck slamming on my breaks leaving the neighborhood cause there was construction going on, and the guy in front of me didn't know what to do so he randomly stopped.

I don't think I'm gonna try solid state cruise at 55 because the sg reads about 32mpg doing that, and averaging that in with my overall trip probably wouldn't be past 30mpg.

Forgot to add, I gotta keep myself from filling up tonight. Tempted to see if I'm really at 29.2mpg or not.

ah! Don't do those short fills!

From what I've seen the lower the tank is, the more accurate each SG calibration will be after you fill up.

But keep up the good work!

Edit: changed the title of my car :D

ah! Don't do those short fills!

From what I've seen the lower the tank is, the more accurate each SG calibration will be after you fill up.

But keep up the good work!

Edit: changed the title of my car :D

No worries, didn't fill it up. Yeah, I always get everyone asking me if my car is an sti. There are no bugeye sti's in the states. Right now the sg is calibrated to display about 10% lower than it's default values. It was right on the money last fill up, but it was a small one, plus I think I didn't fill up completely before. So hopefully it's numbers are a little bit under what the actual numbers are. That'd be nice if the tank average was actually more like 30.2 instead of 29.2 right now.