Another Gas Mileage Question

[huntnfish]

Does anyone know or have any thoughts on the best way to accelerate for the best mileage? Is it better to get up to speed faster or to be easy on it? Anyone have any thoughts on this?

[Whoaru99]

Easy on the gas, easy on the brake.

[Sandmannd]

Yep, easing into it is way better. Also, let your car warm up for a few minutes before you take off.

[harvey lee]

Without a doubt, slow on the throttle.

[IndyEFI500]

According to all the driving courses I have to take at work, take off easy, brake as little as possible. I can't prove it though because my company car accelerator is like stepping on a banana peel. My foot is always to the floor. I do know that the fewer tools I carry, the better the mileage. Up to 20%.

[Steve Bakken]

My ranger always averaged around 18. Now I go as far as popping it into neutral a quarter mile away and coast up to my stop or turn. That combined with the "granny driving" has netted me a solid 20. It's not Honda milage, but it's enough to make me feel better when I pull up to the pump.

[harvey lee]

Agreed Steve. I shift into neutral down the hills and coast whenever I can. Last week going to Huron South Dakota and back, 9 hours round trip, I averaged 20.9 with the pick up. Thats also with synthetic motor oil and gear oil in the rear end.

Now thats not bad for a 1/2 ton Chevy.

[BobT]

No doubt easing up on the throttle at both ends will improve your mileage not to mention wear and tear on your vehicle. Breaking earlier can extend the life of your brakes and tires considerably.

Try this. Slow down about 5mph from what you normally drive. You'll be amazed!

Want to know how much time will be added to your trip?

d=rt where:

d = distance

r = rate

t = time

You have to guess a little at the average speed but here's an example.

Suppose you will be going 100 miles and you normally drive at 70mph.

100m = 70mph * t

100m / 70mph = t

1.43h = t (miles cancel out)

1.43h * 60 = 85.8 minutes

Now slow down to 65mph.

100m = 65mph * t

The result is 92.3 minutes.

Slowing down will add roughly 6-1/2 minutes to the trip but could save you quite a bit.

My car gets about 29mpg at 70mph but I can get around 32mpg at 65mph. That's about 3mpg savings.

100 / 29 = 3.45 gallons of gas ($13.62 @ 3.949/gal.)

100 / 32 = 3.125 gallons of gas ($12.34 @ 3.949/gal.)

That's a savings of $1.28

Not much you say?

60 / 6.5 = 9.23

9.23 * $1.28 = $12.00 per hour savings.

Bob

[slipperybob]

Does anyone know or have any thoughts on the best way to accelerate for the best mileage? Is it better to get up to speed faster or to be easy on it? Anyone have any thoughts on this?

That depends on engine and gearing. For most vehicles slow throttle is better, because it's already enough to accellerate the vehicle. For some vehicle a faster accelleration is better becuase they waste a lot of gas throughout that process. So they only save you gas while the vehicle is coasting and not necessarily at a constant speed.

Check a dyno graph of your engine specs and on the wheel specs. Compare the optimum torque and engine speed. On an automatic you may not have control of which gear at what engine speed, but on a manual you get a feel for how efficient your car accellerates.

[Black_Bay]

I've been hearing a lot lately of guys trying to keep their vehicles under 2000 RPM, especially when accelerating. I tried it and it's very slow. If you don't have traffic behind you it might be worthwhile doing but it won't work merging onto the highway.

[shizzy]

that is very true. Many guys who have the 3.0L in a Ford ranger (thats what I have) found its "sweet spot" is right around 3000rpm's you ctually get better mileage by not shirt shifting it and not grabbing 5th gear unless you are above 55MPH. even with 4.10 gears in the rear and 30" tall tires I still get 20-21MPG in the city

[fishorgolf]

The biggest thing I see people doing is accelerating to the last second and then hard breaking. Look a little farther out in front of you and let off the gas when you know you will have to slow down or stop up ahead. This may be my imagination but the bigger the vehicle the less I see them doing this. I see people in these big trucks stomping on the gas and slamming on the breaks and I just shake my head. I have a 3/4 ton Yukon XL that I mostly only use for towing nowadays and I drive it like and old lady.

[pisces]

Yes, let's not have anybody getting runover by a semi while coming off the entrance ramp in order to save 0.02 cents. As always, use common sense.

[Scott K]

True! the biggest waist of gas is using your brakes! It is waisted energy! Accell slowly, and look ahead and back off the gas and coast to the stop lights. Slow down! These few tips will help alot in a years time! It may seem like peanuts in one trip, but in a year it will add up!

[huntnfish]

I have a 3/4 ton Yukon XL that I mostly only use for towing nowadays and I drive it like and old lady.

I have been accused of driving like an old lady more than once in my 1/2 ton GMC. I don't drive over 65 and am very light on the brakes whenever I can be and it really helps. A buddy of mine swore that you would get better mileage by getting up to highway speed as soon as possible would get you better mileage. Thanks and keep the comment coming.

[slipperybob]

Keep in mind that every vehicle has a different acceleration curve for most effecient use of gas. Many compact cars are quite effiecient at accellerating quickly the first 30 MPH. As since high torque and high HP dyno graph aligns well through those first few gears. Many mid-size sedans excels at accellarating from 25-55 MPH over compact cars. So how quickly a vehicle gets to highway coasting speed depends on the vehicle.

I believe that taking about 5 minutes to get to highway coasting speed is probably the most fuel effiecient as since it'll bare put a heavy load on engine throttle, but that'll just [PoorWordUsage] people off.

Doing it in 6 seconds is probably a big waste of gas as since you'll find yourself having to brake while someone else is doing the slow acceleration. LOL's

Anyway, maybe I think I see more people rolling through the stop signs. But I have notice that there's not been a crash incident at one particular spot that used to get a weekly bumper bruiser. Maybe it's that people are taking a little more time and care to avoid unneccessary expenses.

[BoxMN]

Has anyone else taken a "Smith System" driving course, or equivalent? It is for safety and fuel consumption purposes. Supposedly it can gain a 10-15% reduction in fuel consumption, and the basic premise is accelerating softer, being more alert, anticpating slow downs ahead, using less braking, and leaving more cushion between vehicles. Pretty common sense stuff. But I really thing it works, I took a short course when I was doing some volunteer work. Also took a Coast Guard course then, and those two courses were both totally worth the time and effort.

[BobT]

Pretty much sounds like my driving habits already. Just ask my wife, who complains that I drive like a grandpa even though I'm not...yet.

Bob

[Hookmaster]

Does shifting into neutral and coasting do any damage?

[Macgyver55]

Although its probably very small, yes, it does cause more wear to the transmission and also to the shift column assembly. Each and every time you shift your transmission it causes a band, a servo and/or a clutch to engage or disengage. Any time a moving part moves, it wears to a degree. My personal opinion is it is probably immmeasurable in as much as is the mileage you may or may not gain by doing so. Most of todays transmissions, when in drive or overdrive freewheel when decellerating, so using neutral should not really gain you anything measurable in mileage.

[slipperybob]

So anyway...my car 5 speed manual subcompact.

I've been paying attention and varying the way I was driving, comparing the same route back and to with three fill ups per each. When accelerating slow and keeping car in gear for longer distance, I've pretty much flat out get my 27 MPG. When acclerating reasonably quick and coasting in neutral, I've gotten 32 MPG.

Now that doesn't mean I actually got 32 MPG, it just means I've traveled in wheel distance of 32 MPG, but the engine and gears itself would only get me 27 MPG hwy just as mfg estimated.

So when I'm stuck behind someone and they are driving slow - it's really hurting me.

[solbes]

I've read some of these enormous fuel saver threads on other sites. I've found out there are some fanatics out there, but there are also some very good tips. I read on one of them that you really don't need to totally granny it either for better in town fuel economy. I may be a little off on the actual numbers, but between 80-90% of max torque RPM was the best speed to stay within for acceleration. So for my 4.7L Dodge truck max torque is 2900, which means the best engine speed for acceleration is between 2300 and 2600 RPM's. Had to do with high sidewall pressures at higher RPM's and also by staying out of the lower low-torque areas. I used to really granny it, and I haven't seen any loss by doing this. My automatic wants to shift around these points anyway if you're not goosing it. Crusing is different though, if you can cruise at a lower RPM then do it.

Staying off the brake by giving yourself larger gaps in traffic helps a lot. Syntetic fluids all around have paid for themselves in probably a month or two of summer driving alone.

[311Hemi]

I have always wondered what the exact difference would be. Being I drive a Cummins diesel, I wonder how much of a difference there is between accelerating so I get to freeway speed and drop the RPM down quickly vs slowly accelerating and having the RPM's higher for a longer duration of time.

[slipperybob]

Every vehicle is a little different in terms of highest torque value on the rubber wheel vs motor flywheel and different in each gear. What's effecient driving for one type of vehicle may be inefficcient in others.

I guess that for the most part, some cars should accelerate reasonably quick and get to a coasting speed. They're more fuel efficient while engine RPM is kept low. While others benefit at a slow constant acceleration, because it doesn't trigger the CPU to 'drink gas'.

So I'll acceleration for 1/4 of a block and coast nuetral the other 3/4 way as it's most fuel efficient for me. I'll also probably drop out from 70 MPH at about 1 mile away from the exit ramp and ride neutral to it.