Whats the differance between Amsoil and Royal Purple...??? Amsoil has their new blend of 0-30 wt... they say It will last a full year ..also It can replace your 5-20wt...outlined for your 5.7 hemi... Is that adviseable to change to this different wt..??? Whitch do you use and why...Royal Purple or Amsoil...???
Thanks,, Doug

Amsoil is a much better product, made with genuine Group IV base stocks. Royal Purple oils are decent, but it seems like they create a lot of bogus hype to sell their products. Putting dye into motor oil to make it purple is silly.

Use a search royal purple thins out quickly its a race oil not really an everyday oil... amsoil is a great product

have royal purple in my truck for 2 oil changes now, i love the stuff, gained mpg and noticable power increase over the conventional oil.