I just got a 2002 Toyota Tacoma Prerunner. It's 2WD and has a 2.7 liter 4-banger with a 4-speed automatic transmission. The tranny has a button on the selector for overdrive. Since I don't have the owner's manual to this vehicle (yet), does anyone know if it's alright to just leave the overdrive on all the time? It only makes sense that it should be okay, but I thought I would ask anyway. Thanks!

yes its ok....but you should have got a 4wd

overdrive is pretty much like a 3rd or 4th in the auto trans.  If you need to go to a lower gear just press the button,  thats pretty much what it is.

You can leave it in OD all the time if you want. Its a Toyo and they design for durability. Technically its more wear and tear to do so for most around town driving, but in a  vehicle like that, its almost a non issue. I usually dont use OD when I drive around town because to me its preventative maintenance and less wear but I also have two trans coolers and use Mobil1 syn fluid. I change fluid 1x a year and filter every other year. I have always been like that though no matter what vehicle I drive becuase of my experience with Mopar transmissions. You have to baby those things.

Thanks for the input. I've been a Toyota owner for several years, but I've always had a manual transmission. Just traded my '97 RAV4, and all I ever had to do to it was just regular maintenance(brakes, tune-up, oil change). They really do make a good truck.

Overdrive doesn't work very well on these trucks. When you get above 50-55mph, just shove the gear selector on up to "Race". Look for the "R".