I have a '04 Chevy Colorado, 4x4, 3.5L, 5 cyl. base model. The owners manual says to use Dex III for the transmission, (or I'm assuming Dex VI, which is the synthetic.) I have some Amsoil Synthetic Universal ATF that I'd like to use. The Amsoil site states that it can be used to replace Dex III-H. So my ? is what's the difference between III, and III-H, and can I use the Amsoil? Thanks.
You'll be surprised what you'll never have to do if you put it off long enough