[briank]

In drive-by-wire throttle does the gas pedal position correspond directly with the actual throttle opening? I drive an automatic Scion xB 2nd gen, and one of my objectives when accelerating in 4th (overdrive) is to just push the gas pedal enough to keep the torque convertor in lock-up/ and to not downshift. It would be interesting to know if the manufacturer has set the throttle opening and fuel duty cycle map to continue to slightly increase even if the gas pedal is at the same position. The reason I suspect this is happening is that the instant mpg stays at an almost constant value as I accelerate from about 40 to 55 mph. If the throttle opening remained constant one would expect the instant mpg to increase by 37.5% as 37.5% more distance is covered at 55 mph compared to at 40 mph with the same gas pedal depression amount.

As an aside, I'm thinking of rigging up a resistance spring under the accelerator pedal at the point where the trans TC stops remaining locked. Right now I find that if the instant mpg goes under about 18 or 19 mpg, I am pushing the pedal too much and it go out of lock-up or downshift if I'm around below 42 mph.