courthousedeb

Mine is all city driving and I'm at about 24mpg. Drive to work is 10 miles each way and I can go two weeks at least on a tank of gas. Will report highway mileage when I make my trip to Kansas City next weekend.

SBHHR

I drive a 28 mile round trip to work about 30% city. I am getting a consistent 28 mpg my only mod is a K&N replacement filter and I rerouted my intake hose. I have almost 11k miles on my 2LT.

GCarp

Mainly back and forth to work about 8 miles each way all suburban driving - no highway. Getting consistent 20-21 mpg on 2LT with auto.

Lone Ranger

Below average mpg and excessive oil consumption can be the result of babying it too much during break-in period. If you have been easy on the throttle from day one it may have contributed to your situation. Early on in the mileage of a new car you need to engage in strong robust acceleration to ensure optimum ring seating.

krishaynes

I have driven mine normally since I've gotten it. "It" is a 2007 LS 2.2L w/auto and now has 3000kms. According to the DIC my average mileage is 7.7L/100km which translates into just over 30mpg. Kind of a mix between highway and city... I was averaging 7.4L/100km before a couple of speed burns on the highway though!

nfboy

You're not supposed to drive the piss out of it during break-in.

From the manual:

"Notice: Your vehicle does not need an elaborate
break-in. But it will perform better in the long run if
you follow these guidelines:
• Do not drive at any one constant speed, fast or
slow, for the first 500 miles (805 km). Do not
make full-throttle starts. Avoid downshifting to
brake, or slow, the vehicle.
• Avoid making hard stops for the first 200 miles
(322 km) or so. During this time your new brake
linings are not yet broken in. Hard stops with new
linings can mean premature wear and earlier
replacement. Follow this breaking-in guideline
every time you get new brake linings.
• Do not tow a trailer during break-in. See Towing
a Trailer (Manual Transaxle) on page 4-39 or
Towing a Trailer (Automatic Transaxle) on
page 4-39 for the trailer towing capabilities of
your vehicle and more information."

Someone else here reported a similar problem and it was suggested a reflash might help. If I recall they took it to the dealer, had that done and mileage improved significantly.

tcstoy

I am averaging 24 in town. Haven't been on a long road trip to check highway mileage. Hope to in August. Trying to make plans for the run to Wisconsin Dells.

Lone Ranger

I didn't say full throttle and hard braking, I mentioned strong acceleration. More specifically you should accelerate hard but let off before hitting 75% of redline rpm which is around 4875 rpm keeping in mind the dash tach may be off by a couple hundred so let's say keep it below 4500 to be safe. Once 1000 miles are up, all bets are off and redline (6500) is fair game if you're so inclined. You want maximum cylinder pressure during break-in to seat the rings.

This can be accomplished by leaving stoplights or stop signs briskly, staying below 4500rpm as above and letting off once you're at or near the posted speed limit or 4500rpm whichever comes first.

This practice should only be engaged in when the oil temp is @ 180 or above.

Chizzer

I know this doesn't help, but I get about 11.5-12L/100km. Not bad at all.

Snoopy

Based on how GM "breaks in" their test vehicles (at least before I retired from the Proving Ground), Lone Ranger is more correct than most of the posts on here regarding "break in". They did what was termed "whip schedule" for 500 miles. I use it for EVERY one of my cars in the past 30+ years. NEVER had an oil consumption problem (even using GM's acceptable oil consumption table...which I THINK is unacceptable and excessive).

On a recent G2G with the AZ group to Tucson and up Mt. Lemmon and back to Phoenix I averaged 27.4 MPG with an average speed of 44MPH. Not bad for all the mountain climbing.