View Full Version : overdrive


kirkjerk
08-21-2004, 02:53 PM
Can someone explain Overdrive to me? I'm kind of a weenie when it comes to understanding car engines.

In stop and go traffic, the car seems peppier with O/D off...or is that my imagination?

In terms of: stop and go, highway, stop and go w/ hills, and highway w/ hills, when does it make sense to turn it off? Can you get a sense of that by looking at the tachometer?

What are the implications for engine wear and fuel economy?

Thanks.

Houston40387
08-21-2004, 03:17 PM
I asked a question like that befor and i never really got an answer. I do know that it does give you better gas mileage but i dont really know when you want to turn it off.

GloriousMidget
08-21-2004, 04:01 PM
I also was wondering the same thing . . .

elwood58
08-21-2004, 04:26 PM
The overdrive on the xB automatic is an electric final stage overdrive. It creates a taller forth gear when turned on. The overdrive will keep RPMs lower and save fuel, but at a cost of responsiveness in certain situations. I turn off the overdrive when:

1. Climbing steep hills at varying speeds, and feel the car lugging a bit
2. When going down a steep and lengthy incline. This saves the brakes by using gear ration and engine compression to slow the car naturally.
3. In situation where I need a quicker response to mashing on the gas to avoid a traffic issue or pass quickly.

empleh
08-21-2004, 06:03 PM
overdrive basically gives you a fourth gear. with overdrive off you have only three gears. you want overdrive on when you're on the freeway, and off when you're in stop and go traffic. that the gas mileage part. it's somewhere in the manual.