Oil change time - what to use, Penzoil high mileage at Wal-ly World Options

[djm914-6]

What oil do y'all use?

I've been looking at the 5qt jugs at Wal-mart yesterday and found Penzoil 10W-40. It said something about for higher mileage cars. After looking at the price, I figured this stuff was a no-brainer... Regular price for the 5qt jug was $9.14 (IMG:style_emoticons/default/ohmy.gif)

I wold have bought it right then if there were either more than one jug or if this one was 6qts.... get it $9.14 for 6qts... Maybe I'm alone in my humor (IMG:style_emoticons/default/huh.gif)

[ArtechnikA]

I thought that you couldn't use Mobil 1 on these older motors. I thought i read that this stuff will leak though about every seal in the engine...

partly that's old data, partly it's strue...

the original Mobil-1 from the late '70's wasn't completely compatible with some seals (donno if Porsche seals fell into that category, but some cars had issues...) and it had very low viscosity - like 5.

i wouldn't use any of the new 0W or 5W synthetics in an old aircooled engine, no matter how big the big number was.

i decided to check it our for myself in the 911, and i've been running 15W-50 for a year now. new valve covers and proper gaskets and new oil strainer cover and gaskets cleared up most of the leakage. i've still got a pretty good leak at the back that i hope is the crankshaft pulley seal although statistically it's the #8 main bearing O-ring i can't do anything about.

i made the first couple of oil & filter changes pretty close together in case any gunk got stirred up, but otherwise there are no issues. once we get another running car in the stable i'll replace the crank pulley seal and see what that does.

there probably is -some- risk that it'll leak worse with a synthetic...
what we used to use in the aircooled cars before Mobil-1 was available and affordable was Duckham's Q, a 15W-50 dino oil. i haven't seen it in years.

before that i ran 20W50 Valvoline Racing Oil. that was in SoCal - i donno if 20W isn't a bit heavy for a New England winter, but i'd think a 10W40 (if there is such a thing) would do nicely.