When in the air from a jump and are about to hit the ground, try to land on the start of a hill's downslope. You will pick up more speed. You will then have lots of speed to go over another hill. You will sail across the screen and save time racing the track.

When you are going downhill in the long downhill, press [Up] + [Left]. When you cross a bump, keep doing the same thing. This will make your truck do backflips. By doing this, you will skip a lot of rough terrain, thus saving you time.