Whats up with our LZ1 mileage?

Had good success with some Malibu rentals both 4 cyl and 6 cyl models. My wife who drives very conservatively got combined mileage above 20 mpg on every rental. She had a 4 cyl RAV4 before and got good mileage in the mid to high 20's combined. We just bought a new 2012 LZ1 and now have 1500 miles on it. She is getting 15 mpg combined and 20 with high highway content. What gives? The fuel trims look good on a scanner, all under 3% and there are no codes. Car runs good, she loves it except the mileage. Tried different gas. Her calculated mileage agrees with the avg computer mileage within 1 mpg. Is it the unique combination of the 4 cyl and the big wheels and tires of the LZ1? None of the rentals had that combo. This thing get worst mileage than my full size pick up truck and the same as my old Tahoe. We passed on the 6 cyl of the LZ2 to get the mileage and suffer the performance but it is actually worse in both areas.

Whats up with that! :uhoh:

Thanks,

George

I've only put 2 loads of gas in my LT, but was a bit surprised as well. City numbers are disappointing this early in the game.

Good evening,
I'm sorry to hear that you both are having some frustration over the fuel economy of your new vehicles. New vehicles will not obtain their optimal fuel economy until the engine has broken in. A typical engine will take 3 to 5 thousand miles to break in and during this time period a gradual increase in fuel economy can be expected.

Even so, your fuel economy will almost certainly vary from EPA's fuel economy rating. This is based on a number of factors, such as weather, road conditions, driving and maintenance habits, and the use of air conditioning. For more information on how your fuel economy can vary, or tips to improve your fuel economy, please visit Your MPG Will Still Vary (http://www.fueleconomy.gov/feg/why_differ.shtml) and Gas Mileage Tips (http://www.fueleconomy.gov/feg/drive.shtml) on www.fueleconomy.gov (http://www.fueleconomy.gov/).

I hope this is helpful for you! Please let me know if I can ever be of assistance!
Sarah
GM Customer Service

Estimated mileage is 22/33(26 combined).....not a good sign.....mileage on our car within 1-2 miles from the get go.....

GM has a break in procedure......all you can do is follow it....I love the one where you are not suppose to drive at a constant speed......

The break in period may have something to do with it, the latest mileage was 19 combined. We were careful to break the car in properly during the first 1,000 miles.

Another issue may be the AC compressor load. The system has been intermittently malfunctioning since new. The compressor gets stuck in always on mode and that is probably costing us some fuel economy. It started with the first use of the remote start function but now it is "spreading". Disconnecting the battery resets the system but that is of course not a long term solution.

The A/C problem should be looked at at the dealership....