: Any increase MPG tips?



infin1ty
05-28-06, 12:54 AM
Different tires have made a difference on my car. Unfortunately my new ones have decreased the MPG. Does anyone have any tips for increasing their gas mileage?

danbuc
05-28-06, 02:15 AM
Don't press the throttle as hard.....?:thumbsup:

WOTMODE
05-28-06, 03:11 AM
Pushing vehicle with engine off will result in best possible mileage.

JimHare
05-28-06, 10:56 AM
Well, notwithstanding the excellent, though tongue-in-cheeky replies from the first two posters, here's what I've found to be efficacious:

1) make sure tires are inflated correctly, or a pound or two higher than may be recommended - mfg recommendations are often towards the low side for ride quality. Going from say, 28 to 32 or 33 all around will get you something.

2) Adjust your driving habits - racing from stoplight to stoplight, while fun, is hell on mpg - take off smoothly, with an eye towards getting the transmission into the highest gear as soon as possible. Coast down when you know you'll be stopping - everytime you have to brake, it means you didn't plan well enough ahead. Brakes on my cars regularly last 80-100K.

3) Take any unnecessary junk out of your back seat/trunk - golf clubs, mother-in-law, cement blocks, etc etc. Less weight = better mpg

4) Combine trips when you can. Short trips around town don't get the engine warmed up enough to reach max efficiency.

5) Don't let it idle just to impress your friends. Also, a 'warm' up before driving off is not needed. Start it, count to three, and go. Easy on the gas for the first few minutes, as that's when the mix is richest, before the engine warms up.

6) Make sure there's nothing blocking the air intakes/grill, etc. Frontal area blockage is bad.

7) Keep off the A/C when possible, esp. at low speeds. Turnpike cruising is OK, I don't think the percentage hit is all that noticeable, and the closed windows probably make up for some of it. There have been some studies done as to whether the "windows open, A/C" off mode is better than "Windows UP, A/C on" mode, I don't think they're conclusive, but I'd bet that at highway speeds, the A/C efficiency hit is not all that bad - remember, you're dealing with an engine making 275-300 HP, so the 8 or 10 hp the compressor draws is not a big deal.

8) Use the right oil as recommended.

9) Turn on the DIC to show Instant MPG. After a few days of seeing how often and for how long you are at "9 mpg Instant" vs "54 mpg instant", you'll learn how to adjust driving habits to maximize the mileage you get.

zonie77
05-28-06, 11:43 AM
Excellent post JimHare,

I've seen articles that tested MPG on highway, AC on to AC off, with newer systems the mileage is definitely better with the AC on.

CadillacSTS42005
05-28-06, 11:55 AM
there are also a few mechanical things you can do to increase mpg

1. Clean you TB
2. Replace your fuel filter
3. Replace your air filer
(all apply when they are dirty otherwise theres no point in doing it)

fpmesiIII
05-28-06, 04:07 PM
good post Jim Hare.

Ranger
05-28-06, 04:56 PM
Fuel & air filter will not improve milage.

krimson_cardnal
05-28-06, 11:41 PM
me thinks jimhare hit it - smacked it hard w/ the last point watch the numbers on the DIC

check this for an outside point of view:

http://www.inct.net/~autotips/mpg.htm (http://www.inct.net/%7Eautotips/mpg.htm)

i'm thinking that a clean air filter and fuel filter is going to help the cause, but driving habits are on top of the list...

Ranger
05-29-06, 05:47 PM
A clogged fuel filter will reduce fuel flow. A clean filter will flow more fuel. Now don't get me wrong, I am not advocating a dirty fuel filter, but I don't see the logic in better milage with a new fuel filter.

Likewise with an air filter. That was very true on a carburated engine, but not so on an injected engine. The MAF sensor measures the air flow and based on that information the PCM commands the injectors accordingly. Dirty filter = less air flow = less fuel.

krimson_cardnal
05-29-06, 09:09 PM
i hear you. i also read some where about a clogged fuel filter giving better mpg 'cause less fuel is delivered. that really blew me out.

best mpg is from a well maintained engine/vehicle one should say, so's that's what i mean. keep it up to spec, purring like a kitty and don't drive like a maineeeack.

interesting how this is becoming the concern w/ fuel costs going where they are.

any feedback on the ethanol issues. what needs to be done to a NorthStar to get above the 10%E fuels. think GM is going to move that way??

JimHare
05-30-06, 12:33 AM
A clogged fuel filter will reduce fuel flow. A clean filter will flow more fuel. Now don't get me wrong, I am not advocating a dirty fuel filter, but I don't see the logic in better milage with a new fuel filter.

Likewise with an air filter. That was very true on a carburated engine, but not so on an injected engine. The MAF sensor measures the air flow and based on that information the PCM commands the injectors accordingly. Dirty filter = less air flow = less fuel.


Exactly right - clogged filters will not do anything measureable to affect overall MPG. I had a 1973 Chrysler Newport once that had never had the fuel filter changed. I know this because it had belonged to my uncle and he willed it to me before his demise. I saw that car every day of it's life. On one of my rare days of actual energetic movement, I decided to change it. The filter was literally clogged full of sediment. Looked like it had been submerged at the bottom of the Okeefenokee Swamp for 10 years. The new filter went in, and the mileage didn't move a bit. This was in 1978 and I don't believe things have changed re: fuel filters since then.