Auto FE - It's all about driving style

[Scott_in_Tulsa]

OK. I have been spending a lot of time trying to figure out how to boost the mpg in my 2000 Honda Civic Coupe EX w/ auto transmission for the past month. My whole goal is to save money so spending money on major mods is just not an option.

Outside of boosting the PSI in my tires from 35 to 45, I haven't changed anything to the car in the last month. So I have been focusing a lot on what options I have on driving style. Obviously with an auto transmission, coasting with the engine off just isn't an option. So I have been playing around with my techniques and thought I would share with the group what I have learned so far.

This is for the newbies to this site. I am sure the veterans are all aware of what I am about to list. Most of these relate to highway driving w/ 65 mph speed limits.

1) Reduce Rolling resistance - bump up the PSI in the tires to help reduce rolling resistance and keep an eye on the pressure in each tire. I have two tires that seem to leak air very, very slowly when pumped up to 45 psi.

2) Downgrade Slope Multiplier w/ Neutral Coast - Accelerate quickly down the downhill slope to 5 or 7 mph over the speed limit prior to going up a hill. This uses gravity as a multiplier to boost your mph acceleration with less gas. You can then wait until you have reached the steepest grade uphill and shift to neutral and coast until you are about 5 mph under the speed limit and then add the gas. Be sure to maintain speed with the gas going up hill and not try to accelerate uphill. The less gas you use uphill, the better your FE.

3) Safe Drafting- Never go down the road at highway speeds without trying to be behind someone to catch a bit of draft advantage. Even if it is a pickup truck or minivan, there are advantages to this. Minivans are good because you can often see straight through the minivan windows to see the brake lights of the vehicle in front of it. This gives you more time to brake if traffic slows down quickly. If you can get behind a semi w/ box trailer, your drafting will be even better. I accelerate up close behind the semi (within 20 ft or so) and then shift to neutral and coast for a while. This helps a bunch but this opportunity isn't always available. It also removes the ability to coast uphills as mentioned in #2 above.

4) Side Roads / Access Roads - Most of the time, these roads are much less traveled. If there is a way to drive on these roads at about 10 mph less than the highway or regular route you take, that decrease in speed will help with FE. The trick is avoiding or timing stop lights. That all comes from knowing your route really well and deciding if it really helps or not. With these open stretches with less traffic, you can also add other techniques such as accelerating downhill and neutral coasting up hill. Drafting won't be as much of a benefit at slower speeds.

This is all I have so far but thought I would share with the group. It is so hard to find things that can be used for vehicles with auto transmision that I really thought I should share with the group. These techniques are working for me as I have been able to boost my mpg from 33 to 40 in the last 30 days.

If you have other driving techniques that also help, by all means, add them to this thread. I need more ideas.

[palemelanesian]

I also suggest getting a scangauge. It'll let you see, in real time, what helps and how much it helps. It really helps you optimize your driving style. In a year, it's saved me enough to pay for itself, and now enough to buy another if I wanted.

[tgernon]

so what speed do you reccomend... i just got in to a civic from a crv and i am seeing that the fe speed is not what it was for my crv...

[palemelanesian]

If it's an automatic, whatever speed will keep it in top gear, and just a little above that. Probably 45-50 mph.

Manual - the best speed is slower. Keep the rpms down and use moderate throttle.

[Scott_in_Tulsa]

I agree with PaleMelanesian. It does seem that 45 - 50 seems to be about right for my 2000 Civic. Even if you don't have a ScanGauge (which I don't), you can keep an eye on your RPM gauge and pay attention to when your auto trans shifts gears. With practice, you can learn how to keep it in the lowest range of your top gear for best efficiency.

One correction to my original post, I have since abandoned trying to draft behind trucks, etc. I usually have to run at a faster speed to stay in the draft and it is way too much work to be in that zone and be ready to brake if needed. I have found it is better to run at 63 mph in a 65 and let people fly by me instead. I get much better gas mileage that way and run at a little lower RPM too.

By the way, take a look at my garage log to see the improvements from perfecting these driving practices over the last several months.

[palemelanesian]

Hey, Scott! That's a nice bump in your gaslog chart! Keep it up!

[Scott_in_Tulsa]

Originally Posted by PaleMelanesian

Hey, Scott! That's a nice bump in your gaslog chart! Keep it up!

Pale,

Don't let that last log entry fool you! That was only 3 days of driving over the weekend with perfect driving conditions to hit over 49 mpg.

It did wake me up to the potential of the car though and the impact of driving style on fuel efficiency. I do think that with my daily commute FE will end up around 39 mpg as I continue to put into practice what I am learning.

[1cheap1]

When i first start my old 94 intrepid i put it in gear and just let to go without stepping on the gas pedal. The read out on the gauge that came with the car for mpg starts climbing up to 14 to 18 mpg as i gain speed still not stepping on the gas. It is only going 15 mph but at 18 mpg it is very efficient until warm up and then i start using the gas very gently. This may help you when you start to go in your car.

[Scott_in_Tulsa]

Originally Posted by 1cheap1

When i first start my old 94 intrepid i put it in gear and just let to go without stepping on the gas pedal. The read out on the gauge that came with the car for mpg starts climbing up to 14 to 18 mpg as i gain speed still not stepping on the gas. It is only going 15 mph but at 18 mpg it is very efficient until warm up and then i start using the gas very gently. This may help you when you start to go in your car.

1cheap1,

Thanks. That is interesting. I live on a deadend road so I have a 1/2 mile to go as fast or as slow as I want with no traffic problems. I will hav to try this. It may not be as much of an issue in the warmer summer months as the car will warm up faster or even start out somewhat warm.

[brucepick]

Hi Scott - good going.
I've been hypermiling my auto-tranny car for a bit more than a year now and my bag of tricks is just about identical to yours. I drive mostly highway too.

I also found that drafting is good for FE but I just don't like following that fast and that close. Occasionally I'll find something I can follow at 55-60 mph but not very often.

I've gotten used to driving slower on roads posted 65 mph. I find I'm able to drive 50-55 if that's what I want to do. I do have a big 'MPG' sticker on my back window so maybe that helps people understand why I'm not going 70.

My tires are labeled 44 psi but I have them at about 53. No, I'm not afraid of a blowout. Side topic: with a commute of 60 miles each way I carry a full size spare. If a tire does quit on me for whatever reason I want a fully capable one to complete my trip. I like donuts to eat, that's all.

Carpooling really improves fuel economy. Hurts your mpg just a bit but can double or triple your fuel economy!