I'm looking for a good oil for my '82 Porsche 928 4.5 V8 16 valve with flat-tappets.
The car's had a diet of Castrol GTX 20W-50 for several years, so the engine is heavily varnished now, and the owner before that owner ran 20W-50 as well, but I don't recall the brand. I think it may have been Swepco.
I'm thinking the heavy 20W-50 is serious overkill because the engine never really gets a good workout around here in Va Beach. Redlines at 6500, but the tach never gets over 2500.
I'd like to step it down to a 10W-30 or lighter, but I'm worried about not getting enough Zinc.
I want to use a lighter oil because I think the heavy stuff really bogs the engine down and robs economy, too. Right now I've got PP 15W-50 plus a bottle of Lucas Zinc additive.
I can almost watch my gas gauge needle move as I poke around town.
I also want to run ARX, but I want to run it with the best synthetic I can that won't counteract ARX's cleaning abilities. Frank says that Amsoil XL line will work, but I'll probably need to add some Zinc to it.
Any thoughts?
The car's had a diet of Castrol GTX 20W-50 for several years, so the engine is heavily varnished now, and the owner before that owner ran 20W-50 as well, but I don't recall the brand. I think it may have been Swepco.
I'm thinking the heavy 20W-50 is serious overkill because the engine never really gets a good workout around here in Va Beach. Redlines at 6500, but the tach never gets over 2500.
I'd like to step it down to a 10W-30 or lighter, but I'm worried about not getting enough Zinc.
I want to use a lighter oil because I think the heavy stuff really bogs the engine down and robs economy, too. Right now I've got PP 15W-50 plus a bottle of Lucas Zinc additive.
I can almost watch my gas gauge needle move as I poke around town.
I also want to run ARX, but I want to run it with the best synthetic I can that won't counteract ARX's cleaning abilities. Frank says that Amsoil XL line will work, but I'll probably need to add some Zinc to it.
Any thoughts?