[cfguy2000]

I would like to remind you that I have a 3 speed. If I don't over-ride the auto my acceleration is really bad, so it takes me a lot longer to get up to the good gas mileage speeds (35-55 mph in my car). I am a student, and I have a job, so I find myself doing a lot of short trips on city streets. I have only been keeping my fuel log since January, so I can't tell how much of my improvements in MPG are from driving habits/mods and how much is from warmer weather. I might try to do some experiments on this.

I think delaying the up-shift is a trade-off that can hurt or help gas mileage depending on how it is used. My car's early shift to 3rd gear (at about 20-25 mph) lugs my engine out something fierce, so I have to press harder on the gas pedal to only move slightly faster. I usually delay it to whatever cruising speed I choose (35-55 mph). I look farther up ahead on the road to make sure it is worth it for me to accelerate faster (waste gas) to cruise longer (save gas) versus going slow the whole time (get OK but not great gas mileage). I use my Scanguage almost all the time, it would be impossible to know if there was a difference without it.

I think downshifting manually is better for gas mileage, because I still have control over the throttle (compared to flooring the gas to make the car downshift on its own, like you mentioned). On some hills, I have to downshift manually.

I tried an experiment where I would barely accelerate for a whole gas tank (1 mph faster every 5 seconds or so). This actually resulted in worse gas mileage than driving normally.

Does anyone know if the shift points in an automatic can be adjusted? That would be great.