DEXRON III or ATF4+ is good.
one is for gm and mercon is ford now days they make a dexron mercon mix acceptable to both Dexron III and Mercon V have different specs. You should not use Dexron III in place of Mercon V.
dexron 3 replaces dexron 2, so you could mix them but the dexron 3 is better
No, there is not. General Motors skipped Dexron V to bring out Dexron VI, with the Roman numeral for 6 matching the 6-speed automatic transmission introduced in the 2006 Corvette. The Clevite Kid
Yes dextron 6 can be used in applications otherwise requiring dextron 3
yes
Yes, you can mix ATF3 and ATF4 fluids, as both are automatic transmission fluids designed for similar applications. However, it's generally recommended to use the fluid specified by your vehicle's manufacturer for optimal performance and protection. Mixing different types may affect the fluid's properties, so check your vehicle's owner's manual for the best guidance.
Dexron III. You can Dexron, Dexron II, Dexron IIE, Dexron III, and Dexron V as suitable substitutes depending on availability. Lower numbers indicate a shorter lifespan of the fluid before you need to change it. Do no use Dexron IV (aka Manual Transmission Fluid) as this is likely to cause problems.
Dexron V or VI
No.
Yes . . . All dextron iii applications can use mercon v
Yes . . . All dextron iii applications can use mercon v