slosrtnick

I have a 2004 cts-v that is hp tuned and has magnaflow catback. I'm wondering how I could get the best gas mileage out of the ls6. Gearing is 3.73 t56. Should I try a stock camaro gearing to make the gears taller? What could I change to the tune to have better fuel economy? I would like 30mpg on the highway. Right now I average 20-22, mostly on the highway, with a little city driving mixed in. Any thoughts?

Nick

pwrtrip75

iTrader: (8)

What is your AFR at cruise now? Lean it out a little and test it. You can only go so far before it starts to idle high.. Only thing to watch is the leaner it is the more heat it creates so watch your engine temps. When its hot outside is when you could start running too hot if you are too lean.

Rhino79

iTrader: (7)

Honestly, you will pickup more mileage from timing tuning in those cruise areas of the timing map. Once you get in the upper 15's and low 16's afr you are less efficient and will lose mileage, some setups will even start cutting out in the 16 afr range. Tune the timing and watch the map kpa on logs, a more efficient setup can be observed by lower map kpa and lower tps at a given speed/rpm.

slosrtnick

Ok, thanks for the advice. Do you think I would benefit by putting taller gearing in? I think ls1 camaros are 3.42??...it would lower my cruising rpm. I will check the timing at cruise speeds and partial throttle and make sure it's in check too.

Nick

Old Geezer

iTrader: (3)

I seriously doubt that the 3.42 gear will pick up 8-10MPG.

ctd

iTrader: (1)

Maybe you can run some additional advance @ cruise RPM. You can also run leaner by changing your R/L o2 switch points.

DMM

If your CTS-V is stock, might try some LT headers (Kooks, OBX, etc) rather than try screwing around with a tune to try to get MPG out of an LS6. You can try getting a 3.42 rear out of an SRX and swap it in, but I think that has already been tried and the benefits were not worth the hassle. FYI, the rear diff's on these cars are not interchangeable with Camaro's or G8's, only the Solstice. The rear's are junk and even our upgraded ones do not last long. The tunes are pretty spot on in these cars from the factory to be honest with you, unless you have modded something.

Rather than try to get a 2 1/2 ton sedan with an LS6 to get 30 MPG (which will never come close to happening), why don't you do what I did and spend the $1500 on a Cavalier that gets that or better.

CalEditor@PCMCalibrators

iTrader: (4)

I do a lot of MPG tuning.
Look over this thread.
Please feel free to add to it if you have anything that will help
http://www.performancetrucks.net/for...tuning-489108/