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Originally Posted by Aveomiler
I can select and hold my car in 1st, 2nd and 3rd gears but I can't hold it in 4th if I go under the speed that it's supposed to shift at (I can't upshift early).  |
Unfortunately, you are misinformed about your car's transmission. I also have an Aveo ('09) but it has the same automatic transaxle as yours.
The "hold" button does not work for the higher gears, or the way you think it would - it is only meant to keep the car in a lower gear when on ice or snow so you don't spin your wheels.
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Although since I am able to select and keep 3rd gear, it might be more fuel efficient to shift into 3rd earlier than it normally would as I'm accelerating. I've recently been getting used to "foot-shifting" my car into the gear that I want, but maybe I should try using the gear lever too.
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Again, your perceptions are not correct. I have done a lot of research on this and the problem is with the way the transmission is programmed. The tranny is a 4 speed and is electronically controlled, but unfortunately the shift points cannot be changed. However the biggest problem for fuel economy is the set point for it to go into torque converter lockup. On most cars this happens at around 40 MPH. On the Aveo (and some other Chevy models) this does not occur until 45 MPH - which is way too late if most your driving is being done at 40. When it does lockup it actually feels like a shift - you will see the RPM's drop and suddenly your MPG goes up dramatically.
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As for your other comment about GM's "economy" car, I agree. The 2004 Chevy Aveo was sold having the worst fuel economy in its class.
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Not exactly. The figure for highway MPG is correct and it is excellent at 37 MPG. But the figure for city MPG is inflated - it was probably 24 and the best you will get is 22 MPG, which really sucks. The very wide disparity between city and highway mileage is due to the late TC lockup. (AKA a "slushbox".)
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It kind of makes me frustrated when I tell people that my best tank was 34 mpg doing combined driving, and they aren't the least bit impressed because that's what they expect my car to be able to do. Maybe people will start paying attention when (if) I start getting 40 mpg (Time to work on the aero mods).
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Forget the aero mods. I tried, and it won't help. What we need is way of controlling the programming of the transmission to get it to do the TC lockup sooner.