5W30 in a 302 '68?

[jv68gt]

hi guys.

i dropped my 68 302 gt off at the garage for an oil and lube yesterday, and when i came back for it, i saw on the invoice that they put in 5w30 oil. i usually run 10w30 in it.

any opinions on if 5w30 is ok in this car? they service a lot of classic cars there, i even saw another 68 mustang on the lift when i dropped mine off. however, i just want to be sure and not take chances.

thanks,
jim

 

[d.r.moss]

I just talked to Alternative in Michigan, my dyno place. He told me to run 5W oil in my 302. I thought it was strange, but he knows more than I do.

 

[Loup-garou]

If you have a flat-tappet camshaft, you might want to find out more about the oil that they put in. I don't know for sure, but I suspect that the 5W oils are more likely to lack the levels of that zinc anti-wear / detergent additive that your engine prefers (thanks a lot, EPA...). These new oils are intended for engines with roller lifters or OHC designs. Unless the lighter viscosity causes some ticking lifters or other noises, the oil is probably heavy enough - it's just the additive listing you should be concerned about.

 

[zigmont]

5W30 oil

I agree with Loup-garou about the zinc. A while back the EPA mandated that catalytic converters had to last 100,000 miles. At that time the zinc level in automotive oil was causing the converters to get clogged up too soon, so the oil manufacturers removed most of the zinc. This generally spells death to flat tappet camshafts as they need the zinc to survive, especially high performance camshafts that require higher spring pressures.
I am currently putting a zinc additive in my oil in my 65 at each change to prevent premature camshaft wear.
Rotella T diesel oil used to be the oil to use, but even they are lowering the zinc levels because of the diesel catalitic converters on the newer trucks.
Valvolene racing oil currently has enough zinc, but the lightest weight is 15W50. Amzoil also has enough zinc, but is a bit pricey at $10.00/qt.
I hope this helps

 

[DailyDriver_68]

Zinc Additive

I am currently putting a zinc additive in my oil in my 65 at each change to prevent premature camshaft wear.


So what zinc additive are you or anyone else using?