ocshaman

The way I see it, more economy comes from more effeciency. I know that buying a muscle car to get the most MPG isn't what it is about, but it seems that having 300something ft/lbs of torque doesn't mean using 25 ft/lbs should cost you alot of fuel. I have read about lean cruise with EFIlive, and am pretty sure that most external mods will increase efficiency therefore reducing fuel usage when not WOT. I have set a goal of 300hp, and 30 highway mpg for my next car. I have wanted an LS1 since they first came out.

Now, with MPG in mind with modding, what kind of MPG do you think would be possible with a full weight camaro/firebird/GTO? Corvette is a little out of range, although I am told it would be better. Wideband and tuning will be the most important, but I was just wondering what is possible with the F-body with lid, intake, full exhaust, and TUNING?

NIUhuskies

iTrader: (4)

30 mpgs is obtainiable with a 6 speed cruising at hwy speeds

ocshaman

I know about that, but was wondering what had been done by those trying to get the most MPG.

theguyulove2hate

iTrader: (5)

I was pulling 32 highway with a six speed. Do all of the bolt on's, get a really good tune and that should do it. Its also about how you drive. After you get the MPG your looking for kiss it good bye. Once you feel what those few things do to your car you will want more. Ask me how I know.

ocshaman

I am not after building a car purely for MPG, hence the full weight. Just trying to get the best efficiency. Boltons will give more power when I need it, and allow better MPG when I don't.

lemons12

iTrader: (71)

Possible? All highway? 33-34mpg realistically, I would never expect more... I would actually have to see it to believe it, as in me drive the car and do the math myself.

Stock ls1 fbody M6 should get 28-31 on the highway and around 23-26 in town depending on how you drive.

People make fun of ls1 owners when they want better MPG.. But **** you already have a car that will murder 90%+ percent of other cars that equal it in MPG.. Why not get a few more mpg WHILE adding power? I see nothing wrong with it.

ocshaman

With the rpms as low as they are with stock gears, would going lower be beneficial at all?

lemons12

iTrader: (71)

It gets to a point where higher gears (stock manual 3.42s to auto 2.73s) would hurt. I do not think this would be good.

Lugging is not good... I really can't see you ever using 6th gear, hell probably not even 5th unless on the interstate.

Blk98Vert

iTrader: (2)

Shorter gears would help in a m6 because you can use 6th. For mpg you want max efficeincy. Complete 100mm intake tract, 1 7/8s headers, true duals and 3.73s at minimum so you can use 6th. Also little things like using a 0W oil and making sure you have good fluid in the trans and diff add up.

ocshaman

BLK, if my only goal is highway MPG, wouldn't staying longer be more helpful?

lemons12

iTrader: (71)

In town, 410s would be better than 342s... On the highway, 342s would be better than 410s. 373s would be a good median.

Ronny_02_WS6

iTrader: (6)

I here in Germany and in the Autobahn (Higway) theres no speed limit, so I'm going to stay w/ my 3.42' and already bought my full bolt ons, but when I get back to the States I probably do heads, cam, 4.10 Gears and a Clutch. Trying to save gas money and have to be filling the tank all the time. When I first got the car I stepped on the pedal real hard but now I learned that Fuel efficiency is really important specially for a DD.

ULTIMATEORANGESS

iTrader: (4)

leaving something stock and driving conservatively will optimize fuel mileage.

why stock? because after you mod youl want to drive it aggressively for obvious reasons.

Blk98Vert

iTrader: (2)

No because you want to be able to use 6th gear. 3.73s will allow you to. If you were an auto it would be different. I have 2.73s and hate them getting up to speed, but they do the job. I know I could go longer and be ok. I believe there is somewhere around 2.50 and 2.20 gears.

staleycornell

iTrader: (6)

I have never seen anywhere near 30. Most I have ever got was 24.7 and 90% of my driving is on the highway. I have the basic bolt ons and HpTuners....plus I drive it like it was a Honda.

ocshaman

Staley, by drive it like a honda do you mean rev the h#ll out of it at every stop light, or drive it like there is an egg under the gas pedal? I think some mpg might come from a firmer start at stop lights, higher tire pressure, narrower tires with less rolling resistance.

Latch

iTrader: (8)

I wonder if bumping up the compression (more efficiency) would help fuel economy?

S8ER95Z

iTrader: (3)

I average 26-27 per tank after my cam swap. I spend most of my time highway in 6th gear but it does great. Stock I normally saw 24-25 per tank (dividing miles by gallons).

With the in town driving and passing people on the highway occasionally I have to be pulling 30 something highway. Good enough for me.

Starz T/A 17

iTrader: (6)

For the best MPG I would do BASIC mods. A cackback, lid, and UD pulley. From my experience going too big (LT's, Intake, etc) will hurt MPG UNLESS its tuned properly. The PCM cane only compensate so much to mods

JD_AMG

FWIW 6th gear is very usable with the stock 3.42 gears (which I would suggest keeping if you want to go for gas mileage).
You can comfortably cruise at 50mph (which is a low highway speed) in 6th gear, I know I do.