Dough_Boy.

and technically doesnt mean the old seals are bad conventional oil sweels the seals up more than a synthetic oil which allows the synthetic oil to leak unlike they did with a standarn motor oil.

Fabrik8

You're still saying that the seals are bad. If they've shrunk so much that only thing keeping them functioning properly is the swelling properties of the oil, they're fucked. That means they aren't working the way they're supposed to and are completely relying on chemicals to distort them so they'll do even a passable job. These aren't wine corks we're talking about (bottles are stored laying down so the cork stays wet), they're engine seals.

Plus, most/all off of the synthetic oils made in the last 20 or so years (possibly more..?) have swell additives in them to make them more compatible with old engines in questionable condition that use outdated types of seals.

Dough_Boy.

All seals swell rather them be new or old so no they are not bad. And newer synthetics are just conventional oil with additives mixed in.

Fabrik8

None of the synthetics are just conventional oils with additives mixed in. Conventional oil is just conventional oil with additives mixed in. Blends are blends of conventional and synthetic, to make them cheaper and still perform better than straight conventional oil.


If you're talking about hydrocracked oils like Castrol Syntec, you're partially correct. It starts with crude oil base stocks that are highly refined (Group III base stock), so it technically isn't synthetic oil in the usual sense. It's still refined to the point that it is chemically different enough than conventional oil though.

Most all of the other synthetics (Mobil1, Amsoil) still use PAO base stocks (Group IV), and those are what are traditionally called synthetic oils. A lot of the cheaper synthetic oils use a blend of PAO and the cheaper Group III stocks, so although they're called synthetics they don't have the same levels of PAO stocks that the better synthetics have. Syntec used to be a blend of Group III and PAO, but they removed the PAO IIRC so they're only Group III now. I can't remember if the Valvoline and Pennzoil are Group III and PAO blends or just Group III.

Anyway, none of the synthetics are just conventional oils with additives mixed in, no matter how little PAO they actually have in them. That would be like saying that an apple is just a walnut with additives because they both grow on trees.

Jake.

Fabrik8 jus shittin all over everyones hopes&dreams nbd.

marlinspike

Not really hard to do in this thread though. The stupidity, the stupidity!

Laserjock

Ya but he left out Astroglide

Jake.