Synthetic differential fluid

[siskokid]

I'm sure this has been discussed in other threads, but since I'm new here goes. I've got a 99' K1500 Burb with the G80 "locking differential". (I know this because I have the original window sticker and have checked all the RPO codes). The question is "What are people using in the rear and front differential, transfer case, transmission and getting good results"? I know it's kind of a generic question, but I'm trying to do everything I can to up my mpgs. Keep in mind that I have taken care of all the basic maintenance of the vehicle. Any input helps, Siskokid

 

[dirtclod]

synthetics

Synthetic tranny and gear oil is the way to go. It maintains lower viscosity (thickness) and pressures in cold temps. Your engine has less resistance rotating the gears. And supposedly, it doesn't break down or need changing as often. Some say, it has twice the life expectancy. But it is a thinner fluid and has a tendency to find small pin holes in gaskets, sometimes causing new drips.