Because Diablo tends to have a bit more timing than Superchips, if you're towing heavy loads use good quality, name brand fuel of the highest octane you can find. Carry a bottle of octane booster just in case, though its rare to have problems. Just remember that octane booster, best case, is going to give maybe 1 full point of octane (not 3-8 like most claim).
I've only run into a problem with ping while towing on one occasion and it was very minor.
Chips are programmed for premium, 89 isn't enough.
