The manual for my 1998 Frontier recommends shifting from 1st to 2nd at 15 MPH, but two days after the dealer changed my oil, the engine cries out to be shifted into 2nd at 10 MPH. Manual also says that max speed in 1st gear should be 30 MPH. Now, at only 20MPH, it sounds like it is way over-reved. Shift points have lowered for evey gear, and mileage has gotten worse. I took it back to the dealer, and he says that nothing is wrong, but I know it is totally different than before.
Do you have any idea what the problem might be. Thank you.