Been running my 5 star tuner the last few months on 87 performance. Loaded the 87 tow this weekend...gonna hook up the 5th wheel this week and head to the Oregon Coast....will see what it does.

 

Truck ran good with the 87 tow tune. Plenty of power and fuel mileage was good.. tried the 89 tow coming home and it was ok...ended up with a P0171 and P0174 code.....also a P1702 and P1783 codes. Have to check these out.