T4 is "Natural, free range, gluten free" oil.. T5 is a blend of T4 and some synthetic stuff .. T4 is a better oil for your older engine because of its different additive package.. It is available at Wal Mart for a good bit less than West Marine.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.