Hello from Metro NY

[Thymeclock]

Hi everyone,

Some of you may recognize me from Ecomodder. I'm on Long Island and have a new 2009 Aveo5. Satisfied with it except the disappointing FE in city driving. I'll be visiting a Chevy dealer soon about it and I'll post details about exploration of possible cause and remedy.

[Daox]

Hello Thymeclock.

What kind of mileage are you getting in the city with the Aveo?

[Thymeclock]

Hello Thymeclock.

What kind of mileage are you getting in the city with the Aveo?

22 mpg in all city driving. That's with using a scan gauge and driving conservatively. It makes no difference how slowly you accelerate because the car is simply remaining too long in the lower gears. The A/T is late in all the upshifts and doesn't go into high gear until 45 MPH (and most of our driving is below 45, unfortunately). I think there is a problem with the way the transmission is programmed. Here are the details: http://ecomodder.com/forum/showthrea...tml#post165578

[Mervap]

Wow....I hope it's just an issue with the A/T programming and not actually a "design feature". That's a big drop-off in economy vs the manual.

[MetroMPG]

Let us know how it turns out with the dealer.

If it's "operating within spec" or whatever the dealer usually says to absolve themselves of responsibility, Orange4boy over on EM was working on a hack that permitted manual control over torque converter lockup. Not sure if you want to get into that with a warrantied car though.

The other thing I'd wonder: if you're driving mostly short-ish trips, the ECU is likely programmed to hold lower gears longer until the coolant temp is nice and toasty (to light off the catalytic converter). So an engine block / coolant heater would probably make a noticeable difference in that case. So would a heater for the transaxle oil.

[Thymeclock]

Let us know how it turns out with the dealer.

If it's "operating within spec" or whatever the dealer usually says to absolve themselves of responsibility, Orange4boy over on EM was working on a hack that permitted manual control over torque converter lockup. Not sure if you want to get into that with a warrantied car though.

The other thing I'd wonder: if you're driving mostly short-ish trips, the ECU is likely programmed to hold lower gears longer until the coolant temp is nice and toasty (to light off the catalytic converter). So an engine block / coolant heater would probably make a noticeable difference in that case. So would a heater for the transaxle oil.

I began a new thread about it in 'Fuel Economy' so this information will receive more notice.

The weather is now unseasonably warm here (over 60 degrees today) and it does the same thing. Ambient temperatures are not involved, as the programmed shift points are immutable.