Have a few Questions

[PhqChevys]

Originally Posted by Longshot270

If you are focusing mainly on economy, tow tunes have a tendency to get better fuel economy. They may also be beneficial in the type of driving you do. They are designed to get tires turning and keep them turning. My tow based tune gets better mileage than my performance tune because of that. It is also better behaved in crowded city driving because it isn't as jumpy due to a less aggressive throttle map. With the tow based tune my truck is actually the same speed as everyone else, just with more grunt power. The only problem is it does not have the same get up 'n go as the performance tunes until you are at upper highway speeds. If you dont usually use 91, that might be worth considering.

Funny... my truck is exactly opposite of yours. My truck get's around 15-16 mpg in 87 performance tune and around 13-14 mpg in 87 tow tune. I asked Bill about this and he said that with the tow tune the A/F ratio is much richer to keep the cylinders cooler while under the heavy load of towing... makes since to me...