The only true way to find out how fast your car or truck will go is to radar it yourself. Different elevations will change top end speed. And it does not matter what nitro content you use either. The higher the nitro comtent the quicker you will hit your top speed. Nitro content will not give your engine more rpms. When its maxed, its maxed. We tested 20% tuned to 250 degrees and the cen car ran 49mph consistently. We put 33% fuel and retuned engine to 250 degrees. Again we hit 49mph consistently, but it got there quicker. You can buy a radar gun for about $79.00 on ebay. Just search radar gun.