I'm wondering which kind of tranny ATF is best for my cars. I currently own:
1990 GMC Vandura 2500, 350 cui TBI, TH700R4 transmission
1991 Pontiac Firebird Trans Am, 305 cui TPI, TH700R4 transmission
1994 Pontiac Trans Sport, 231 cui SFI, 4T60-E transmission
Now for the GMC and the Trans Am, the manuals tell me to use Dexron II
fluid. The Trans Sport manual tells me to use Dexron II-E.
I understand that Dexron II is not in production anymore and has been
superceded by Dexron III fluid. Now if I look e.g. at Valvoline's
product line, I can see that they have mineral ATF und synthetic ATF.
Now is synthetic ATF better for the transmissions or is it just more
expensive? Or would it be better to go with mineral ATF for the older
TH700's and synthetic ATF for the newer 4T60-E?
I don't know what's best for my cars. Suggestions welcome.