Quote:
Originally posted by TXTERRA78:
In response to the "does turning the O/D off actually increase acceleration" question:

The answer is yes, and not just for an Xterra, but pretty much any vehicle with an automatic tranny and overdrive. Same thing as driving in "D", as compared to "O/D". By driving with the O/D off the transmission allows the engine to rev higher before shifting gears up. OD is great for the highway when you're at a fairly constant speed as it keeps the RPM's lower and thus conserves fuel usage.
I'm not quite sure if turning the overdrive off changes the shift points and I'm not inclined to root through the service manual to check, but it may be the case. However, it's more the fact that by turning the overdrive off and forcing the engine to kick down to third gear vs. asking it to strain against fourth gear, you'll get better punch. Otherwise it will simply unlock the torque converter in 4th gear and while the engine will rev harder, much of the output and gas is going towards stirring the fluid in the torque converter. Eventually it will build power to the wheels, but not nearly as efficiently or as effectively as it will in third where the TC does not unlock except in a few rare conditions.

Brent
_________________________

Tip: see if your question has already been answered before asking it. Try our handy-dandy search tool!