I have just installed a Superchips Microtuner 1715 on my F250 SD with the 5.4 gas.I measured the tires like the directions say and it measured 33" even though they are 315/75/16. But they say to measure from the ground up while mounted with the weight on it. The speedo seams to be fine now. Also made a much better shift. At first i tuned to the towing performance, i could tell a little difference but not much so i had to try the performance without tow, now i can tell quite a bit of difference. I only tow in the summer time when i pull my pontoon boat to the lake. I was gonna just gonna tune to the tow performance and leave it, i was kinda afraid of setting to the max performace and leave it for just every day driving and just change it to the tow when i tow the boat. Is this ok, good or what do you guys think? as you know this is a very heavy truck and i got the large tires, i dont want to damage anything. Iaso not sure on the customs opions either like the shift points and stuff, now its set at max and shifts later than stock and seems to tach out to around 5 when i punch it but seems fine during normal acceleration.Please feel free to comment

 

Yes, its okay to leave it in that mode when not towing. When towing you might experience engine ping if you don't have it in tow mode. Tow mode also has different shift characteristics.