bigalnash

Im going thru a quarter of a tank from just everday driving, sure im not light on it. But im getting 14.6 miles to the gallon. I think when My car was in the shop they thought it was the mass air flow sensor but that wasnt it (replaced it anyway) Im thinking maybe they used the wrong one or didnt tune it right? .... I just replaced my 2 rear tires due to the car being out of alignment. I used the eagle f1 all seasons for the rear and still have the potenzas up front ... maybe that has something to do with it? and i had the car realigned as well. If anything that should have improved the economy but nothing....... any ideas I dont think 14.6miles is normal.

bugzy530

iTrader: (1)

CONSIDER URSELF BLESSED I HAVE AN IMPALA SS MAKING 12.8 MILES A GALLON ID KILL FOR THOSE MILES U GET

JP_GXP

What are the driving conditions, stop/go, long highway, mix? Around town (stop and go) bet I get is 18, worst 11. Highway, best with DoD removed 30, normal 28.

bigalnash

mixed mostly and when i merge on the highway I like to put the pedal to the metal till i have to stop then its just smooth sailing. Then I get the routine stop and go .

keviiinn

iTrader: (1)

I've gotten as low as about 8mpg on a tank from 100% city driving before. Best I've ever gotten from a full tank is about 21 when I was on cruise control 75mph for like 90% of the time. So your numbers sound about right as far as I'm concerned. What are you expecting from a full size V8 sedan?

Hell'sChariot

iTrader: (24)

I had an 06 imp ss and it got around 22 hwy. Now I got an 04 goat and am getting around 24 hwy...I'm much happier with the goat!

JP_GXP

Why is the Impala's mileage so bad compared to the GP?

Panther427

Stop and go kills your MPG in these cars. The wost i have got is like 13 driving in first and second gear around town. usually with mixed driving i'm at 18-19 mpg. 23mpg high speed hwy, and close to 30mpg on secondary hwys 65mph spreed limits
Try accelerating below 2500RPMs dont let it get any higher than that on flat roads/slight grades.

06 SS

high stall, low STR converter + stop and go traffic = low MPG.

20SS07

My normal driving which is strictly stop and go driving in the suburbs where there's stop lights or stop signs all over the place I never get more than 14.5. When I do get on the highway I can get mid to upper 20's. During the summer I travel alot during the weekends and with not driving a whole lot during the week(my commute to work is VERY short) I've been getting around 20.

Pauls325

iTrader: (1)

are you running a tune? if you changed your cat overtemp controll you may have melted the element in the cat. otherwise any exhaust leaks upstream of the 02 sensor or even a bit after couald be causeing extra fuel to be added.

other than that try unhooking the battery for ten minutes this will erase the learned fuel map or whatever and make it re-learn you will know when its reset when you have to set the date in the DIC

06 SS

The LS4 car's are heavy for being so small. They are also in V8 mode in stop and go traffic, they also suck a lot of fuel for being relatively little engines (I idle mine all day sometimes at work during the winter and they burn more at idle than either of my LT1's). The torque converter is horribly inefficient until it locks up. These things all add up. If you are almost always in stop and go traffic, it might pay to get a different torque converter. Assuming the computer could be appeased with a tighter converter, and that it not necessarily a given with the throttle by wire, it would change the demeanor of the car considerable. You would have quicker throttle response and more efficiency down low. You would get a little twitchier launching as it would be harder to not spin and would probably feel the DoD switch more. If I drove in only around town conditions, I would seriously consider changing it though.

BuffaloSS

iTrader: (3)

That's good info, Doug. I'm with the majority above, and my 11mpg with pretty much straight City driving all day and 20s sounds about right. When I'm on the highway, it's 75+ or bust, so there's no helping there on the short trips that I do make.

Where would one go, and what would they look for, in a new TC? Certain brand? Model? Stall speed regardless of brand?

nitr0racing21

iTrader: (5)

for the GXP you are hitting boost to much

06 SS

Like all things, it pays in the long run to go for quality. Pick a well known manufacturer with a good reputation, ask if they could make you something in the range of a 2000-2800 (your choice) stall with a 2.0 or so STR. If they can do it with a smaller diameter case, that is always a plus. Just be as sure as you can that you can program it to work before you start.

06 SS

Too much boost? Methinks you are confusing the LS4 (small alum 325 V-8) with the supercharged V-6 of the GTP.

Bryan921SS

I get around 14.5 in the city and 23ish on the highway at 75 mph.

The boost comment was funny...he is a little special with most of his posts....


I am sure you guys could get more out of these cars with a fuel conscience tune.

Mgpeagle

iTrader: (6)

I just put in a smooth intake elbow and got rid of the accordian style one that is factory and I gained .2 mpg. I paid 20 bucks for the elbow and the car has smoother acceleration too. This was a good economical mod. Just throwing this out there.

-Mike

02gmc5.3

iTrader: (11)

My truck with a 5.3 never gets much worse than 14.5 around town, but then again the best tank on the highway was only 19. It's odd that a car with the same basic engine and about 1500lbs less weight would get mileage worse than my truck.

bigboy3l

I get 15mpg on my daily drive. lots a hills 20-40mph some lights and stops.

When my Filter gets dirty It starts dipping in the 14mpg range clean re oil back to 15's.

On the highway I have gotten up to 27 mpg on some trips all cruise. but try to stay 70 or under. otherwise it drastically drops.