how many use synth oil?

I use Amsoil 5W-20. I change every 7500 miles. My '96 has 180k on it now. Sold a 2001 with 150k, and I had an oil analisys done before selling. They told me no signs of wear, pus the oil could have gone longer than 7500 !

Mobil 1 is good to, but a BIG waste of money if you are going to dump it every 3k. Just use Dino oil.

G-Man

Mobil 1, if I can get the right grade. 5W20 no longer avilable where I live, so it's Castrol synthetic, as everyone who wants their wheels to last forever.

technically, i doubt /anyone/ here is using a true synthetic oil. most everything sold as "synthetic" here in the us is in fact a group III mineral oil, including mobil 1. don't get me wrong, m1 is a fine oil, but all this hoopla about "synthetic" is marketing semantics, not chemistry. true synthetics are specifically labeled as to what their base oil is. if the oil is not so labeled but still called "synthetic", it's a group III. the [mis]information you see on the interweb on this subject is quite extraordinary in its utter pervasiveness. i guess wishful thinking is easily cultivated with a little strategically placed bovine excrement.

There is more speculation and misinformation on this subject than one can ever hope to sort out. No, Mobil-1 isn't using a Group III base oil. Yes, some other synthetics do. However, the bottom line is that the Group III vs. Group IV (PAO) base oil debate is pretty much over and it has been widely demonstrated that extraordinary good motor oils can be made with either one. Group III synthetics start with crude oil for the feedstock of the chemical transformation process. Group IV oils start out life as natural gas. Why some people get working into a lather about the distinction of starting with natural oil or starting with natural gas is a bit mysterious to me. That said, Mobil-1 still uses PAO as the base oil.

I have yet to see any bottle of motor oil from any company which spells out the base oil and additive chemistry used.

John

no, mobil 1 has only 5% pao. therefore, pao is /not/ the base, it's simply a [minority] additive.

there is indeed more speculation and misinformation on this subject than can be believed. mobil 1 may have been pao base at some point in history, but that's not the case today.

forgot: "I have yet to see any bottle of motor oil from any company which spells out the base oil and additive chemistry used."

here are a couple of examples of products identifying the base:

msds info often gives additive info, although it has to be said, msds filings are woefully inadequate, incomplete, inaccurate and untimely in this arena.

Well, doesn't that just suck!

The transmission company that I work for is switching exclusively to Mobile 1. It's a somewhat large company, and Mobile 1 is actually going to start packaging it in gallon containers just for us. The guys in the tech dept. claim it's the best tranny fluit out there. As a matter of fact, we're going to start recommending trans fluid changes every 5 years instead of every year because of it.