Fuel efficiency

**V8MUSCLE** · 06-18-2009, 08:10 PM

I realize having a V8 and fuel efficiency in the same sentence is kinda bass akwards, but what is the most fuel efficient way to drive our m6's.

Ive driven a lot of manuals, but one was a truck, and the others were gutless wonders.

I know somebodys going to chime in about babying a ls1, or how our car is made to rape other cars, which i still do, but when im just going to and from work how can i get the best mpg.

Ive done a little experimenting and have found that cruizing around in 6th at 45 is worse than being in 5th at 45.

There is no way that the skip shift function helps with gas mileage, everytime it kicks in and i go to fourth it bogs way down.

typicaly i shift around 1.5-2.5k rpms depending if im going uphill/load.

i was wondering what anyone else has found helps or hurts our mileage.

**Orcus79** · 06-18-2009, 08:15 PM

what may help is to remove the skip shift, there are few ways to do it from kits, to resistors.

Once that is done, I shift short like about 1500, doesn't seem to hurt anything.

**V8MUSCLE** · 06-18-2009, 08:21 PM

from what ive experienced there is a fuel efficiency "window." To many rpms and you burn a lot of fuel, to few rpms and you have to get heavier on the gas to make enough power to accelerate. i just want to know if anyone has found that window.
For me it seems to be 1.2-1.5k rpms cruising, and 1.5-1.8k accelerating.

**Orcus79** · 06-18-2009, 08:22 PM

Thats about right where I am.

**V8MUSCLE** · 06-18-2009, 08:27 PM

The tornado TB spacer gave me about 5mpg, but it whistled loudley. screamed at WOT. so i took it off.

**david_viny** · 06-18-2009, 08:34 PM

From a start I skip from first to third some times. Usually if the road is flat or a little downhill and I know I wont be slowing down I'm in 5th at 35mph ish. I try to stay under 2,000 rpm for reg driving, I'm getting 22-23mpg mixed driving. This includes several WOT runs though. I cant make it a full tank without spirited driving lol.

**V8MUSCLE** · 06-18-2009, 08:37 PM

Originally Posted by david_viny

From a start I skip from first to third some times. Usually if the road is flat or a little downhill and I know I wont be slowing down I'm in 5th at 35mph ish. I try to stay under 2,000 rpm for reg driving, I'm getting 22-23mpg mixed driving. This includes several WOT runs though. I cant make it a full tank without spirited driving lol.

lol, i have the same problem. i keep telling myself that i wont get on it, then i find myself 120 on the highway running the first thing to rev at me. i have gotten a lot better about burning out everywhere i went. tires are freaking expensive.

**karpetcm** · 06-18-2009, 09:18 PM

sometimes ill start in 2nd, other times ill go from 1st to 3rd 4th to 5th in city driving. The only time i go WOT is when im on a on ramp. Otherwise i hate going WOT for no reason. Either way without really trying i get about 17-18mph and thats mostly city, if i really tried i would get a bit better, since i hardly ever drive my car id like to have a little fun with it by changing gears as often as possible and thats usually 2500-3000rpms shifts at best lol. These cars have good torque, unlike my E46 M3 i had to rev the Sh*t out of it to get any type of feeling that its fast.

**silverWS6** · 06-18-2009, 10:56 PM

i guess i've been wasting alotta gas!!

i shift at like 2300 or 2500 or on a slow drive, which hardly ever happens

, i shift at like 2k... maybe its the 4.10's? and ooooooooo boy do i love just flooring it as soon as i shift to second and feeling the back go side to side!! or even just driving 1st normal, 2nd normal, and 3rd floooooor it!

anybody else do this?

**DaddySS** · 06-19-2009, 01:42 AM

Conserve momentum - anticipate stops so you use less fuel to get going again. The energy you burn up in braking has to be replaced.
Keep the RPM between 1600 and 2200
1-3 shift
Keep it under 65MPH
As the old shell ads used to say - treat the gas pedal like there is an egg between it and your foot.

Now having said that, I can't make it through a tank of gas without breaking the rules, but those are the guidelines.

**zparker** · 06-20-2009, 03:37 PM

my 98 m6 gets about 25 to 26 mpg to work 28 to 29 mpg on atrip with ac on stock 3.42 rear . drive like you want lifes short whats a few gallons .

**cammed goat** · 06-20-2009, 03:46 PM

I shift around 2500/3k and if I am traveling in a 25 mph zone, I leave it in 4th. 35-45 mph I leave it in 5th. Highway is in 6th. Coming to a stop I either trans-brake or leave in neutral until fully stopped.

**SSnow** · 06-20-2009, 07:00 PM

1st, 3rd, 5th about town driving, 4th & 5th on back roads. A liitle blast now and then to get it out of my system. I've done 26 mpg on cruise control at 70 on the highway. Never less than 20 mpg on a tank full of fuel.

**Firebirdjones** · 06-21-2009, 11:10 AM

I shift around 2,000 rpm around town driving. And anything at or above 25 mph I use 5th gear with stock 3.42's. I cruise around town in 35 mph zones in 5th gear all the time, and routinely chug the motor down to 7-800 rpms if we have to slow down a bit, rarely go to 4th unless we slow below 25 mph.

Once above 40 mph I use 6 gear exclusively. Motor pulls fine down to 800 rpms or so at 40 mph.

Around town driving like this I get 21-22 mpg consistently.

On a recent highway trip with cruise control set at 80 mph and the AC blowing,,,we got 29 mpg. Cruising rpm of about 1900 rpms.