broncobuyer
Registered User
what is a safe rpm range for an idi on a long haul towing? my 89 f250 has a zf 5 spd 235/85/16 tires and at 65 mph it revs 2600 rpm, at 75mph it revs 3000 rpm and at 83 mph its hitting 3400 rpm which is in the yellow, im assuming i have 4.10 gears because of the high rpms, what would be a safe cruising rpm when towing with these trucks?