Differential Oil... Synthetic or Regular with Posi additive?

[TA_GTA]

Hey guys just wondering what oil i should use on my 88 GTA its the borg warner rear end. Just wondering if theres an improvement by using full synthetic rather than conventional oil with posi additive?

[79 Z28]

no dont use synthetic, use non syn. and the gm posi additive, good to go

[TA_GTA]

no dont use synthetic, use non syn. and the gm posi additive, good to go

Thanxs man :sanchez:

[89vert]

no dont use synthetic, use non syn. and the gm posi additive, good to go


what do you got against synthetic?

posi additive is a must

[91Vert]

I watched on Horse Power TV a while back buy using ROYAL PURPLE sythentic in ur Engine, Trans and Diff and adding a coolant additive could reap u gains of up to 15h/p.
Jason u seem to be all about power so whats your beef against SYNTHETIC.

[iroc22]

theres a guy on the net that dynos all the changes he does to his 96 WS6 and when he changed to redline synthetic in his tranny and rear end he netted 5 rwhp.

[79 Z28]

no dont use synthetic, use non syn. and the gm posi additive, good to go


what do you got against synthetic?

posi additive is a must
its not as good for the clutch discs believe it or not. but if you got a locker or spool syn is fine. ive heard this from rearend gurus. they believe in it, and thats how i roll.

[79 Z28]

theres a guy on the net that dynos all the changes he does to his 96 WS6 and when he changed to redline synthetic in his tranny and rear end he netted 5 rwhp.
garunteed most of that was from the tranny. power loss in the diff due to oil is purely oil drag on the ring gear. unless you have a thinner oil etc. its still gonna be the same parisitic loss.

[383TA]

Newer ford explorer 8.8 rearends take both synthetic and additive...Not sure of the clutch pack material though. Synthetic is pretty potent stuff, you're not supposed to use rtv silicone to seal the cover up, it will leak.