Scotty, I've got a 2002 Chevy Blazer ZR2 with 200,000 miles and the original engine I always keep well maintained.
100% Conventional oil seems to be getting harder to find. Should I switch to a synthetic blend?
I've always used 100% conventional 5w-30 oil as the owner's manual says, but that grade of oil is getting harder to find.
Many products I once used that were not advertsied as "synthetic blend" now are and I'm not sure what's safe to use in my GM 4.3L Vortec engine.
I currently have an oil leak at the rear main seal, and would switching to a 5w-30 synthetic blend make it leak worst? I understand that synthetic oil of the same viscosity rating as the conventional counter-part are thinner and that worries me.
Yes, it will make it leak worse. You're going to have to fix it anyway, then you could use a synthetic blend. My personal opinion is that these so called "synthetic blend" oils have so little synthetic in them that it doesn't make any difference. It's just a marketing ploy to get you spend more money. Why don't these oil companies ever tell you how much of this "blend" is synthetic and mineral?
