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So I've been lurking for some time, and have learned quite a good deal of Hypermiling techniques - just starting to put them into practice.

I have a MT, and have always thought it is plain logic that the lower the RPMs, the less gas usage. Therefore, I try to get up to 5th gear asap even if I am going down a side street. Of course I am aware of the lack of a power band when I do this, but I'm always prepared to ds if need be. I'm assuming that I'm using less fuel when I'm going 30mph down a street in 5th at 1500 rpm versus the normal 3rd gear at 2700rpm.

However, I've recently heard some critics of this technique on another message board.

Here are some responses:

Does this actually save gas? When I shift early, I always feel like the engine is working harder when you let the hears climb.

More then likely the engine will have to work more to catch up to the gear and in turn waste more gas.
Stay within the gears RPM's and drive normally will more then likely yeild you the best mileage.

Yep, this puts too much stress on the engine. Have you ever ridden a mountain bike before? Imagine putting it in the highest gear and trying to pedal from a start... pretty much impossible, right? That's what it's like for the car. There's a list that Toyota recommends for when to upshift and downshift, fortunately somebody just posted it elsewhere, so I can post it here.

That is crazy... I get 31MPG using my 4th gear when climbing hills at 80 when I'm breaking in my tC.
So 5th gear has to make your engine work so much harder to go to a certain speed than the gear that speed is supposed to be on. (REMEMBER, 5th gear is OD!)
Lets say the car is going 35 MPH, and you use 5th gear, it's like the same consumption of fuel as in redlining 2nd gear. (You should always keep your RPM at 3-4K RPM and your tires at 35PSI to get best mileage.)

I used to shift at 2500 assuming it gave better gas mileage. But with how the gear ratios are setup, it makes the engine work much harder to get up to speed than to just ride out those extra 500 rpms. For optimal fuel economy, shift at 3000. And it's not too boring that way too.


So there is disagreement on if this is an efficient way to drive, and if it does any harm.

I do this on flat roads, if I'm on an incline I'll shift according to the demands of the road. I can't see how riding out 5th at 25+ MPH can damage the car, and how it can't help save fuel.

Thoughts???

There IS a minimum rpm that will work for the given conditions. It varies based on load, slope uphill or downhill, and whether you're accelerating or decelerating. If you can floor the pedal and nothing at all happens, you're too low. You'll need to learn that limit for your car.

Once you are above that minimum, keeping the rpms as low as possible is good.

For reference, on my car, I can maintain as low as about 33mph in 5th gear. That's about 1500 rpm. If I have to accelerate at all, I have to shift. Except when merging on a freeway, I keep my rpms below 2,500 at all times.

Welcome, TC_Spool!

Oh boy. Some of those quotes make me cringe!!!

In general, you are correct. Highest gear with lowest RPMs will give the best mileage. If you have total control over acceleration rates (meaning, not pressured by traffic) you can always get better mileage by shifting early. Just don't make your accelerations TOO slow -- then you'll spend more gas just because you are staying in lower gears longer and still also spending gas increasing your speed instead of maintaining it. There is an optimal acceleration rate which will depend on your particular vehicle.

Personally, I'm typically in 5th at just barely under 30mph when accelerating, though I can loaf along at less than that. I tend not to do much steady state driving anymore as coasting in neutral uses so much less gas. Coasting with the engine off is even better. That's a bit more advanced than what you are probably ready for, but the basics of shifting remain the same.

I highly recommend a ScanGauge if your vehicle is new enough to use one ('96 or newer) -- there is a link you can buy one from in the left column of every page on this site -- look for the image of the red and black box. If you get one you can see the fuel usage differences in real time as you try each of the scenarios suggested above in your quotes and you will see that you get worse results that way. As long as you are careful not to lug the engine and thus avoid extra high strain on the engine you should be just fine.

Good to have you and keep asking those questions!

It sounds like you could really get a lot of value out of a ScanGauge or something similar.

I also love to use 5th gear frequently, but "lugging" is not a good idea....got to determine the best rpm - it may be around 1500. In my instance of driving an Insight, upshifting too early puts more of a strain on the hybrid battery pack. :(

There are times I wish for a 6th gear to for going downhill - other situation I'm not using gas.

Hi TC Spool:

___Like Sean (Right Lane Cruiser) pointed out, some of those quotes made me wince in agony :angry: Remember who your target audience is wrt the real answers vs. “My granddaddy told me …”. This is where the real FE is achieved and running anything up to 3K is a total waste :( Easy on the accel pedal and shift as fast as you feel but at lower RPM’s and higher throttle plate openings (ICE is doing work but in a more efficient manner) and you will discover what works in short order once SG-II equipped.

___As for steady state cruise, FE while in 5th at 1,500 will absolutely trounce 3rd at 2,700. No doubt about it in anything with a stick I have driven.

___Accelerating in fifth … now here is one that is a real concern. Dropping the hammer at a low RPM while in 5th can burn a lot of needless fuel and a downshift or two would definitely be best practice depending on how hard you need to accel. If it’s a shallow grade but only few block long upward slope with no impediments (no signs, lights or you are on the highway …), DWL while in 5th is even better.

___Good Luck

___Wayne

In general, you are correct. Highest gear with lowest RPMs will give the best mileage. If you have total control over acceleration rates (meaning, not pressured by traffic) you can always get better mileage by shifting early. Just don't make your accelerations TOO slow -- then you'll spend more gas just because you are staying in lower gears longer and still also spending gas increasing your speed instead of maintaining it. There is an optimal acceleration rate which will depend on your particular vehicle.

What I usually do is get up to my speeds through quick shifts while keeping an eye on the rpms. So let's say I'm on a side street that's 25mph. I'll get up to that speed using all the gears, ending up in 5th but at a very low rpm. I always do neutral coasting when possible along with FAS'ing.

However, can you please elaborate a bit on the 'too slow acceleration' you speak of? Are you saying that if I'm in 5th gear on that same side street and the speed limit goes up to 45mph, don't stay in 5th - rather jump down a gear, get to the speed limit and go back to 5th for the constant speed? Is there a good measure of my acceleration being too slow (besides the obvious taking forever to get to my desired speed!).


I highly recommend a ScanGauge if your vehicle is new enough to use one ('96 or newer) -- there is a link you can buy one from in the left column of every page on this site -- look for the image of the red and black box. If you get one you can see the fuel usage differences in real time as you try each of the scenarios suggested above in your quotes and you will see that you get worse results that way. As long as you are careful not to lug the engine and thus avoid extra high strain on the engine you should be just fine.

Good to have you and keep asking those questions!

I'm thinking about the ScanGauge - I see it also offers traditional CEL functionality so I get the two tools I want combined into one - pretty cool. Regarding this tool - how does it differ from the factory 'real-time' mpg estimating (I don't have this feature). Can I actually read my MPG for a set trip - such as to work and then reset it?

Thanks for answering my questions - I'm sure I'll have tons to follow as I perfect my techniques!




For reference, on my car, I can maintain as low as about 33mph in 5th gear. That's about 1500 rpm.

Is there a reason that you don't go under 33mph in 5th? Limitations of your engine - too much strain?



I also love to use 5th gear frequently, but "lugging" is not a good idea..

Can you please define lugging in your words? I know the concept - I'd like to better understand if I am doing it!

The car will "shake" when it luggs - it like climbing a hill shifting too high on a bike. I'd expect more metal-to-metal contact when lugging - bad.

The lowest rpm to avoid lugging depends on the load - higher if going uphill, lower if going downhill with no gas.

What I usually do is get up to my speeds through quick shifts while keeping an eye on the rpms. So let's say I'm on a side street that's 25mph. I'll get up to that speed using all the gears, ending up in 5th but at a very low rpm. I always do neutral coasting when possible along with FAS'ing.

However, can you please elaborate a bit on the 'too slow acceleration' you speak of? Are you saying that if I'm in 5th gear on that same side street and the speed limit goes up to 45mph, don't stay in 5th - rather jump down a gear, get to the speed limit and go back to 5th for the constant speed? Is there a good measure of my acceleration being too slow (besides the obvious taking forever to get to my desired speed!).


Yes, for a 25mph to 45mph change I drop from 5th to 3rd, upshift at about 32mph to 4th, run 4th up to 42-43mph, upshift to 5th then to 45mph. (assuming that I'm going to now do steady state 45mph). Rate of acceleration without a ScanGauge I'd say keep your foot at just about 1/4 throttle or slightly less. With SG, I vary between watching LOD (60-80%) or GPH (for my 2.3L I try not to exceed 2.5GPH). If you accelerate at only 1/16th throttle, it will take you a lot longer in distance to reach 45mph, reducing the length of your potential coasting, whether it be feathered throttle while in gear, NICE-ON coasting, or a full-on engine off FAS.

Lugging is trying to run the engine at too low of an RPM for generating power like accelerating, for example trying to accel from 20mph in 5th (900 rpm for me) would be lugging it, but it will maintain steady speed with just a touch of throttle or not without lugging. In typical Chicago crawl and maul, I am jumping through 5 gears from 0mph to 20 mph for the typical rubberbanding of crushing traffic. I can beat EPA highway mpg in this kind of stupid traffic, which most of the people where I work think is impossible.

It s a bit complex... Generally from what Ive seen, keeping the speed moderated in the 30-50MPH range, and using a direct drive fourth gear, if you have one (i.e. gear ratio is 1.00:1) yields best fuel economy, compared to doing the same speeds in OD 5th gear without lugging. This has to do with driveline efficiencies induced by a direct drive gear.

Saab had written a report some time back indicating that skipping gears could be a good idea, as if only mild lugging is encountered, no significant wear was induced, and the engine was fine with it, in fact providing higher efficiency. Im sure this is within reason, of course.

If you are rolling real low RPMs, and need more power, please learn how to double clutch well. Just because your synchros will makeit OK doesnt mean it is thebestthingfor your trans.

JMH

TC_Spool, both Chuck and Ken have given good answers so I'll address your other questions.

The too slow acceleration I'm referring to is when you creep up to speed. You may expect that to save gas but in fact you'll be using more over that interval. If you speed it up what you will find if you monitor the gas usage is that from creeping accelerations you'll get better overall mileage as you accelerate faster until you reach a certain point (again dependent on your vehicle) at which accelerating faster will start returning worse numbers again.

In other words, there is a sweet spot for the acceleration rate that will give you the best mileage overall and you will get worse mileage if you accelerate either faster OR slower than that rate.

As for trip mpg tracking, yes the ScanGauge is very useful in that respect! It even is intelligent enough to reset back to 0 if the car has been off (as in ignition key in the off position so none of the electronics is running) long enough. It only does this for the "Current Trip" meter, but also keeps track of Tank, Day, Yesterday, and instantaneous mileages. Actually, come to think of it the Day and Yesterday reset as well -- guessing based on how long the car is off, again. I never actually use those so I tend to forget about them. :o

If you want to reset any of those earlier than it would automatically do it for you, there is a reset menu selection for each readout.

I hope that you do purchase one of these marvelous gadgets -- they are absolutely indispensable when learning how to drive most efficiently, and even after that they are a significant boon in the pursuit of ultimate mileage on any route. If you click on the banner in my signature you'll see what I mean. I got the device and joined this site in April -- the results speak for themselves. :)

Is there a reason that you don't go under 33mph in 5th? Limitations of your engine - too much strain?


My limit is about 33, depending on the situation. My older civic only has a 1.6L 105 hp engine, which means there's no power right off idle. I keep it in a range where the rpms are as low as I can, while still being useful.

When I'm accelerating, I'll shift 1-2 as soon as I'm moving, then 2-3 at 20mph, 3-4 at 30, and 4-5 at 40 mph. Usually, I go straight into an engine-off coast, so I rarely actually cruise at 33 or whatever.

It s a bit complex... Generally from what Ive seen, keeping the speed moderated in the 30-50MPH range, and using a direct drive fourth gear, if you have one (i.e. gear ratio is 1.00:1) yields best fuel economy, compared to doing the same speeds in OD 5th gear without lugging. This has to do with driveline efficiencies induced by a direct drive gear.


I disagree. There is some inefficiency introduced, but it's minimal compared to engine efficiency. Keeping the engine in an optimum range is MUCH more valuable.


And a big YES to getting a scangauge. I bought mine in April - 20%+ improvement since then. See my Mileage Log below.

Hi JMH:

___Unfortunately in the real world, fifth will eat up a 1:1 4th in 85 + % of driving scenarios.

___Something that I hope you will take with a stiff upper lip and in stride. Please become a serious hypermiler first before you begin to post with authority. Some of the stuff you have upped today is so far from the mark I do not know where to begin :rolleyes:

___Good Luck

___Wayne

Hi JMH:

___Unfortunately in the real world, fifth will eat up a 1:1 4th in 85 + % of driving scenarios.

___Something that I hope you will take with a stiff upper lip and in stride. Please become a serious hypermiler first before you begin to post with authority. Some of the stuff you have upped today is so far from the mark I do not know where to begin :rolleyes:

___Good Luck

___Wayne

Ummmm, as an engineer and the analytical sort, I have performed this test at length and with replications. I can tell you that with my BMW E30 and its direct drive 4th gear, given the RIGHT speed range, 4th will kill fifth in fuel economy.

Unless we are making apples to apples comparisons, any global statement, is generally incorrect. We all can only post from experience and whatever REAL, statistically significant analysis we have performed.

Im hoping to learn a lot on here, but want tobe sure not to get caught up in the false economics ofsome of this stuff. If bringing this point out is offensive, I apologize, but it still is reality. And, NONE of us have done enough of the analysis in that regard to make any real statements. It is all hypothesis from what I have seen.

Since I cant and will not present point data, Ill be sure to provide adequate citations from now on with my comments, so that they have more clout... I guess my ability to consistently obtain extremely high longevity and consistently high MPG beating EPA highway numbers by 3-4 in MIXED driving isnt enough... Perhas I should submit my statistical evidence to show that I was in the club before I ever heard of this site, without any of the gimmicks presented :rolleyes:

If youre comment about me bing incorrect is due to the comment on the Odessey, excuse me for not knowing that it is flat towable - wasnt aware that this should be common knowledge. As for 12V battery SOC voltages, thatis somewhat common knowledge, look at the industry standard (BCI) charts for calcium and antimony doped lead acid batteries... those charts indicate the accepted values. My comment on 4thgear is based upon real testing that I have performed under documented conditions with my vehicle. So what is the issue???? Please note that most everything I have posted has been questions, because I am looking to learn and improve upon what I know.

JMH

Hi, JHZR2!

With due respect to your engineering background, all of my vehicles have also consistently returned 3-4mpg over the EPA highway rating for entire tanks of mixed driving. I've always been concerned with vehicle longevity as well and I can tell you that on three separate occasions not long ago the mechanics at the dealership actually requested to meet the owner of the car they'd been working on. All three mechanics said they had a hard time believing the car had more than about 20K mi because of the wear state of all components. It was very obvious to them by looking at the mechanicals both that I'm assiduous about my maintenance and very easy on my vehicle. I have also made it a habit (unless there is extreme need for acceleration) to shift into 5th no later than 40mph in all of my vehicles and I've received the numbers you seem to be implying are the result of remaining in 4th gear.

Please don't take the above as criticism or even a disproval of your observations. It is just to establish a common understanding with you.

This site has many members who have done a lot of testing over many tens of thousands of miles in their vehicles. We love empirical data here which should strongly appeal to your engineering bent, and a number of us have done detailed experimentation to help determine the best methods of obtaining good mileage. If you search the forums you will find that there have been extensive and thorough studies done on gear selection, acceleration rates, engine load parameters, road conditions, oil viscosity, and other related minutia. I don't recall any that show that a direct drive gearing enables parasitic losses from the transmission to be a larger factor than engine rpm in terms of efficiency, but I think I speak for all here when I state that we'd be delighted to learn any new ways to save even more fuel by being more efficient!

With that said, if you have repeatable results that work on more than just the vehicles you have access to, we'll all be glad to change our habits. So... in the spirit of peer review could you detail what you have done to test out the 4th vs 5th gear question? Do you have instrumentation that allows you to do instantaneous fuel consumption comparisons in order to help with this? The SG is an excellent tool for this purpose and I can tell you that my car either doesn't have a direct drive gear (haven't checked, honestly) or for some reason it doesn't behave the way yours does. I know that my last car did not behave that way either, but I can see it directly with the SG in my current vehicle.

With respect to the battery, I do not know what to tell you other than I just replaced my OEM battery at 91K miles -- after 5 years of solid service? I've been turning the engine off any location I know I will have to wait for the entire life of the car and it was finally starting to complain. That seems like an awfully long time to last given your statements, but maybe mine was special somehow?

Longevity is a really good concern to have, but I can tell you from observation of the results obtained by many drivers here -- and Wayne in particular (hypermiler extraordinare if you haven't noticed!!!) -- over the course of many many miles, in many many different vehicles that when hypermiling is done correctly there does not seem to be much in the way of measurable adversity to automotive components.

So please stick around and post your thoughts and experimental results. If we can help you progress, great! If you can help us out, so much the better!!

I look forward to reading future posts from you. :)

Hi JHM:

___First off, 3 – 4 mpg over the EPA means little to most of the experienced members here. Everyone reading this could perform that feat in their sleep and double it under the right conditions. If you think this is false economy then by all means continue to beat the EPA year round by 3 – 4 mpg and be happy with the result. I do suggest that you purchase a more fuel efficient vehicle and drive that for 3 – 4 above its EPA instead for all our sakes.

___Let me present a bit of evidence to you about the real world vs. any tests you may or may not have performed vs. what we have done.

http://www.cleanmpg.com/garage/images/11.png

___Again, you are presenting yourself as a knowledgeable individual and I respect that but what you have posted (especially about the 4th gear stuff) doesn’t match what I have seen in maybe 100 vehicles to date and with a paltry 3 – 4 mpg above EPA, you are nowhere even close to figuring out what your Beemer is or isn’t actually capable of in any gear let alone speak with absolute certainty about it.

___What I hope is that you go out on a clinic with a rated hypermiler near you (if you are in Chicago, I would be glad to give you one) and then you will have a template of sorts to see what is actually available to you. Right now, you are in the baby step phase and with a fair amount of reading, some practice on more desolate roadways and some real world experience will eventually show you what works and what doesn’t. Right now, you are just to green :(

___Good Luck

___Wayne

I do appreciate all of the insight, and while I will be the first to say that I do not know it all, at the same time have been driving with a keen interest in improving fuel economy at all times. To the crowd here, 3-4 over EPA highway (old numbers) in mixed riving may not be all that great, but the consideration that I run AC all the time and have never had the (what some would consider) inconvenience of shutting down an engine, taking corners without brakes, withstanding PA's horrible roads with 70 psi tires, etc., I cannot complain.

I want to be able to see and determine what works and what may not work. Having 100k+ worth of data and experience is a great inroad into proving the validity of something. Surely havng replicates of this tells even more. Information overload sets in easily when being new to a forum that has LOTS of posts. Learning and an understanding of some of the more "historic" discussions/battles (every forum has them, this one surely does as well) will certainly help.

As I stated in my introduction, economics is the most important thing to me. Not 'greenness', not happy happy pollution reduction, but rather bottom line effects on my wallet. To me, a car is not broken in until 100k, and if 200k cannot be obtained with minimal effort, the vehicle is junk. Some will disagree, and this is fine. To this end, my ultimate method of obtaining efficiencies in vehicle ownership is to have them last. Contrary to this end is the idea of buying a new car, which is a horrendous pollution addition between paint sprays, metal forges, carpet, foams, etc. Thus, I cannot agree with this:

I do suggest that you purchase a more fuel efficient vehicle and drive that for 3 – 4 above its EPA instead for all our sakes.

Because it is a poor use of money, 100k mile vehicles owned since new, and it does in the act of making something, intorduce extra pollution to the environment, which is my third (at best) concern.

That said, there is a lot of great wisdom in this forum, and it certainly seems like a fun place to read through threads. It will be a good place to spend my lunch hour! I appreciate everyones' responses to my questions, posts, etc., and look forward to learning from everyones' insight as I go through the process of digesting all of the historical threads in this forum.

Best,

JMH

Hi JHM:

___May your reads here at CleanMPG be good ones ;)

___As for 100K miles to start, there are quite a few great used Hybrids available for decent prices that may interest you vs. the Beemer you are currently driving? The fuel savings alone over the next 100K miles should take care of any premium costs needed to procure such a vehicle and thus save you all the green you want while doing the right thing in so many other ways.

___As a footnote, I took a couple out on a clinic in a brand new 05 Prius loaded up with camping gear, 3 adults and A/C set to a comfortable 75 a few years back. 85 + mpg over a RT 15 – 20 mile drive was the result. Prius’ do everything automatically all the while being quiet as a mouse and in a league of their own while under EV if you care to take one out for a drive ...

___Good Luck

___Wayne

I like the idea of a prius, and after my BMW wears out, then I may well look at one (though since its justme driving, an insight size car would be better for that application). Unfortunately I dont have paths to ride a bike to work on the nice days... talk about green! Wouldnt be interested in used cars though anyway, I only buy new by personal choice. Since I keep the cars so long, depreciation is really a non-issue.

I still maintain that the best solution to minimizing costs and minimizing total carbon footprint, if you will, is to get good life out of what you already have. a 1.8L BMW isnt a 6.0L SUV. There dont seem to be issues with 1.8L corollas or civics, why a BMW? If I can consistently get 40 MPG in that car (currently getting about 31 mpg in my no interstate, six stoplight, 8.9 mile commute), whats so bad about that??? Its an existing automobile, no manufacturing related pollution has been made in me consuming a replacement for a car that currently runs like a top. Trading the car in and getting a new one when there are no issues with this one is not the choice for me, as it would take a LOT of fuel savings between 31 or 40 MPG and 60 or 70 MPG to make up the cost...

Hopefully before too long theyll bring us some hybrid or diesel station wagons... then Id be ready to trade up!

Best,

JMH

JHZR2: I for one appreciate your concept of keeping a vehicle long term: just look at the vehicles in my signature. They all have at least 130,000 miles and are maintained fairly well, tight money at times restricts some things. I used to drive the 98 Ranger as my primary vehicle, it was originally provided by work as a company car, and then was given to me as a bonus. I let wife and kids use it now, I drive the 96 with the 5 speed as my primary vehicle because I generally put on more miles per month and its the best mpg machine out of the bunch. We were getting about 19-21 mpg with the 96, and if you look in my logs you can see its now quite a bit different. Yes, I am pulling out all the stops and then some. I'm not sure right now what I'd get if I went to only mild hypermiling techniques.

Perhaps a better comparison for you might be my 98 Ranger with AT. We generally got about 16-18 with it, and if you look in the logs you'll see that the wife (mostly) and the kids (sometimes) are generally in the 16 range, which is EPA city, and have some tanks up near the combined EPA of 18. Several times I have driven it recently with my younger son to show him some mild techniques, no engine shutdown at all, and easily get 21-23 mpg. This is in a suburban environment. That beats the EPA city number by 5-7 mpg, and the combined by 3-5 mpg. With shutting off at long lights, the mpg will rise, amount depending on length of trip. So what I'd say is that if you are getting 3-4 mpg over EPA city in city driving, you are doing 'OK' - much better than the average driver for sure. A little tweaking of technique, even without engine shutdown at long lights may gain you another couple mpg. Shutting down at known long lights on your regular commute may gain you another couple. Timing the lights so that you don't come to a complete stop (while not impeding traffic of course) may gain you another couple mpg. Little things make differences. Of course, you don't NEED to go to the more advanced or some might say extreme techniques... I understand that, and for example I won't show or encourage my kids or my wife to do most of what I do to push the envelope. I have gotten as high as 29.0 mpg in the 98 Ranger from home to work (11.5 miles suburban/city) using every trick I know. If I use only mild techniques, I get about 22-23.

I guess what I'm saying in rather a long winded way is go for the level of techniques that you are comfortable with. Get a ScanGauge so that you can build your own datastream of results from your driving of your car. The ScanGauge gives the important feedback to adjust your style: I use different rates of acceleration, different pulse points, different coasting points, etc. between the two Rangers.

I look forward to seeing more posts from you.

So what I'd say is that if you are getting 3-4 mpg over EPA city in city driving, you are doing 'OK' - much better than the average driver for sure. A little tweaking of technique, even without engine shutdown at long lights may gain you another couple mpg.

Im getting 3-4 over EPA highway in mixed driving, FWIW. I do have a scangauge, have had it for a good while and like it a lot.

My one question would be what constitutes a long light? Daimler did some analysis way back that said that it takes about 30 seconds worth of fuel (assuming idle fuel consumption) to restart a vehicle, when one assumes increased alternator load, light off fuel load, etc.

Ive since read (IIRC, it was an analysis by BMW) that stated that modern engines utilize the equivalent of 20 seconds of idle fuel consumption to start the engine.

Its tough to time things like this sometime, though shutting down to coast into a light certainly increases the time.

So, what is your criteria for a 'long' light? Have you noted any real numbers for startup fuel consumption to determine the break even point? I'd be interested to know your strategy.

Thanks,

JMH

I've been working off the idea of about 10-15 seconds as break even point, based on articles and comments both here and at a couple of other websites. Most of my highway driving I do NICE-ON coasting as my Ranger doesn't seem to coast long enough to get 15 seconds of glide to warrant engine off. I think I have an idea of a way to use SG to do an experiment to compare fuel consumption at idle vs. restarting. It would be fun to see the results.
BTW, went 35 miles in mostly heavy traffic on 294 today 38.5 to and 40.8 on the way back, and when traffic was at speed I ran between 50-57 mph (way back was mostly at good speed) this was with all NICE-ON coasting.

Hi JHM:

___Transport Canada has been promoting a 10-second anti-idling method for years with there own tests. A modern day FI ICE uses ~ 7 seconds worth of fuel for a start. If you have ever driven a hybrid, you will find they shut down at every opportunity once warmed up.

___Good Luck

___Wayne

thanks! Id imagine that the setup on a hybrid is a bit difference, but its good to know that 10 sec is a rule to go by these days.

Appreciate the info!

JMH

Just a little food for thought re: gear ratios and fuel economy. To me, the real magic of the Prius isn't the battery and electric motors. It's the way it uses its CVT to manage ICE operation to keep it working at peak efficiency across the load range. Something we have noticed is that, for the most part, the engine is operating at moderate to high load (75%-85%) and increases and decreases engine speed to meet power demand. So in effect the accelerator pedal acts like a gear shift rather than a throttle actuator. To me, this is suggestive of best practice for people with manual transmissions.

Of course, the Prius doesn't run the engine at such a low speed and wide throttle opening that it's rattling itself to death. Below about 1600RPM it starts to close the throttle plate and use it to control power down to minimum speed of about 1200RPM. It's worth mentioning that its small size and atkinsonized valve profile don't make for anything that you would call "low end grunt." So the electric motors and battery come back into the picture there. But I figure "normal" engines should operate well at least that low in the RPM band. My Accord was fine down to 1200-1300RPM as long as I didn't need a lot of power. I just down-shifted if it sounded "unhappy" or couldn't produce enough power to get me up to speed.

Aww, now you've done it. You've made me miss my clutch pedal...

You people may think you know it all , But from what I read your all a little crazy, Dense, and just love to spend the few bucks you may be saving in gas. If you want to know the most efficent way to operate any car, or truck. Go to Autometer and buy a Vacuum Guage. They cost about $45 with the panel to mount it. Once you people learn how to opperate and read the guage you will understand how the engine works and what creates "load" on it. The guage will read about 18 to 20 inches at idle with no load. The closer you can keep the engine to this "no load" condition the more gas you'll be saving. I don't care if its at 25mph 75mph or what gear. Watch the guage and use the gears to accomplish this "no load" reading on the meter and you can't do anything better. You people want to spend a million dollars to save $5. A little understanding of basic physics wouldn't hurt you either. Putting the car in 5th gear at anything under 50mph is just plain foolish and heartless to the poor car. You have to have the horsepower (torque) to be able to turn those gears. Your just putting strain on the poor engine and wasting gas. The name "oldschool" was not dreamed up. I've been in the automotive field longer than most of you have been alive. I could go on about gear ratios and tire sizes and many other things, But you young people don't listen, You have to have all the latest Tech nonsense when all you really need is some sense.

Well you sure told us oldtimer.:Banane14::rolleyes:

My Element loves 5th at 35 and 1750 rpm.

How stupid of Toyota and Honda to put anything more than a vacuum gauge in their vehicles.

I declare a troll. Two posts, neither one with anything but insults.

You people may think you know it all , But from what I read your all a little crazy, ............................ You have to have the horsepower (torque) to be able to turn those gears. Your just putting strain on the poor engine and wasting gas. The name "oldschool" was not dreamed up. I've been in the automotive field longer than most of you have been alive. I could go on about gear ratios and tire sizes and many other things, But you young people don't listen, You have to have all the latest Tech nonsense when all you really need is some sense.

While I agree that sometimes people don't pay enough attention to the wisdom of their elders, I don't think all the elders went to the same old school. "Putting the car in 5th gear at anything under 50mph is just plain foolish and heartless to the poor car." probably isn't advice you should give without knowing a bit about the gearing, engine and load on the car. My Grandfather's (born 1905, died 1997, former ship engine mechanic and auto mechanic who lost his garage in the Depression) advice conflicts with yours on this point. "Shift as early as you can without lugging the engine unless you need to accelarate." I rode with him driving that way many times in a variety of Ramblers and Subaru's.

Following my grandfather's advice, my wife's Aveo and the F350 Turbo Diesel I often drive at work both do fine cruising in 5th at 40 if they don't have a load on, but fill the Aveo up with people or pull a skid loader behind the F350, and I need to use higher Revs in 4th to pull more torque to climb hills at 40. Of course I won't win any drag races hitting 5th at 40.;)

Another piece of useful advice that my grandfather often gave me (usually about unfamiliar vegetables) was "don't knock it till you've tried it." For a Do-It-Yourselfer like me the scangauge gives access to a lot of useful information from the computer besides just being a vac gauge/FE calculator. It's dead simple to install and switch between OBDII vehicles (two minutes tops). For someone like me who switches between vehicles at home and work it is way cheaper than installing several new gauges in about eight vehicles. Besides, It makes me feel smart to help my friends by reading/resetting their cars' error codes.:)

Yeah, like anybody else, some of the people here are a little nuts sometimes, but if you have an open mind you'll probably pick up a few worthwhile tips.

I declare a troll. Two posts, neither one with anything but insults.

boy... at least Im actually asking questions within my doubtful statements ;)

Hope Im not a troll...

JMH

Hi Old School:

___I think you better go back to new school and learn the new math. Calculating fuel trims in real time with an abacus just doesn’t work these days :D

___Good Luck

___Wayne

Back in my day, we just put a brick on the gas pedal and let er rip. It's obvious the faster you get there the less gas you use. Then we'd deploy a grappling hook if we needed to stop in a hurry.
And if we were going a long way, we'd carry a spare can of gas in the back seat and have ole Earl lean out and pour it into the tank on the fly.
Yep, we just zipped along with our brick on the pedal, ripping up the tarmac with our grappling hook, spewing gas in our wake and we liked it that way. We loved it. You young whipper snappers with your fancy cruise control and wiper blades and seat belts think you know it all don't ya?


:D