When you dyno a automatic do you dyno with the Tow Haul on????

 

i'm inclined to say no!

 

The Guy at the Dyno place said to turn it on when dynoing it... I didnt know if I lost any HP because of that or not.....

 

well, the tow haul button doesn't make hp. all it does is raise the line pressure and allow the engine to get higher in the rpm band before shifting. unless you have an aftermarket tune that all the performance is set up for your tow haul i don't see it helping you. i don't see it robbing you of power either tho. in my way of thinking anyway.

 

I have an aftermarket tune.... and when the Towhaul is set on it makes the firm shifts go away....