Bought an 06 SS 2.4/ auto a few months back. Had a four wheel alignment done, low rolling resistance tires @ 38psi, Mobil 1 synthetic oil, K&N air filter, and I get 28mpg hwy with the air off and windows up, trunk empty at 60-65 mph. I thought it would do better than that. I have a 91 Z07 Vette that gets 32.8mpg loaded down at 80mph when we travel! Any ideas?

Thanks

 

Altitude kills. That's all I can say. I also have a 07 2.4, but with the manual tranny. I'm seeing similar mpg. However, this car is mostly driven in the city for short tips, and at slow speeds, mostly 30-40 mph. My car was rated for 29/34. This is exactly why the EPA changed the tests for mpg. IIRC, the current tests reduced the numbers quite a bit and you are seeing mileage that reflects the more accurate results. Also, the tranny plays a factor. You have a 4-speed that weighs more than the 5-speed I have. More weight and fewer gears are bad for fuel economy. Also, I believe the old tests were set to test hwy economy at 55mph. Therefore, at a higher speed, and higher rpm's, you would reduce your fuel economy.

Also, what octane are you filling it with? GM recommends premium (91 or 93 depending on where you live, and your altitude). Lower octanes are okay though.

 

89 octane. Most runs are between Omaha and Kansas City. Altitude is not a factor and mostly level highways. The car gets 21mpg in city driving with the air on.

 

How many miles are on the car? Are you stock other than the air filter?

 

i run 93 octane i get 24-25mpg city and 27-28mpg highway at 65-70mph i also have a 2.4/auto

 

wow... i use 91 and get around 34 highway.... im a 2.4L auto also.

 

The car has 20,600 mi. and is stock except for the air filter. I will try a higher octane fuel and see if there is a significant improvement.

 

when I use 89 I get about 29-30 highway at about 65 on less than 1/2 hour drives. but if its a long ass trip using 93 I avg about 41. 06 2.4 also

I have a lot more miles than you but... mines completely stock.

 

i have 2.4 sedan with automatic tranny i will post my gas mileage tomorrow because i have to drive from north jersey to Baltimore then on saterday i have to drive back so i will get back on the gas mileage .....last time i think i got 33mpg on that same trip but that time i was really good and feathered it the whole way and used cruise control .......usually i get about 27-29 mpg when going 70-85mph no cruise control and not maintaining steady rpms

 

i always run 91 and i get around 31-36 on the highway and 22-26 city

 

Do your guys' avg mpg gauge fluctuate while your driving depending on how you guys drive. Mine barely moves when im going 65 with cruise on it just stays at 25.2-25.4 mpg

 

I have a 2.2/auto but at 65 on the highway I get 34 mpg. With 20k have you changed the fuel filter. I dont know what the recommendation is on mileage replacement but all it one bad tank of fuel and your fuel filter can partly or even fully clog. I had it happen to me once. I installed a new filter before i went on a 1500 mile road trip. Half way on the trip, I filled up for the 3rd tank of the trip and by the end of that tank of gas the car ran like ****. Stopped in to the closest dealer and after some tests they told me my fuel filter was clogged. They replaced it and the car ran fine.

 

spark plugs...

 

just finish my trip to maryland and back i got 25mpg while crusing at 85 to 95

 

I have an '08 G5 GT with the auto. (2.4L LE5) And I use 87 octane. Is that why? If so can I get some good links to why? (My wife doesn't believe it)

I tend to get 23-24 city. And got under 30mpg from Charleston up to Washington DC. I want to know what I am doing wrong. The car has 6K miles on it. Cruise was set 70-80mph the whole way.

 

These cars were rated at and get the best MPG at 55mph. For each MPH over 55 your MPG will go down.

 

I have a 2.2L auto and get 37 mpg doing 70mph & a whopping 45 mpg doing 55mph. Then again I got an intake, full exhaust, full syn oil & ngk IX plugs. City driving i get abuot 26-27 mpg.

GM recommends 91 rated octane(I think) for the 2.4. I used to use 89 or 91(depending on gas station) and I received lower fuel mileade, but then again gm recommends 87 w/2.2L

 

everyone with a 2.2 says they get like 38 i get 28 and my car doesnt see 4k rmp

 

my DIC is inaccurate, find ur MPG the old fashioned way, i personally get about 30 MPG while my DIC says 24