[gmachinz]

I only use Mobil 1 and either a Mobil 1 or K&N filter. No need for "high mileage" synthetics-just use the regular Mobil 1. I don't even use the SuperSyn stuff. If anybody really wants detailed info on oil differences I could go on forever BUT-Im sure people will say "what about RP? What about Joe Gibbs Racing" ? blah blah.

Here's the scoop-unless an oil company discloses actual performance numbers, I don't care what they "claim". Here's the two most important aspects to look for in an oil:

1.) Rate of evaporation
2.) Film strength

IMO everything else is moot if these two numbers are poor. Rate of evap. refers to how much heat an oil can take before it begins to break down (oxidation is another term...that's the varnishy brown junk you see under your valve covers, etc.) and synthetics are much higher than conventional oil here. Film strength is the pressure at which an oil can resist being squeezed out from between two surfaces (ie bearing/journal)

All non synthetics are considered a Group III hydro cracked carbon and here are their numbers:

1.) 350F
2.) 1200 psi

Now, Amsoil is rated as:

1.) 600F
2.) 3000 psi

Amsoil is tops but I should note Mobil 1 is only barely below those numbers so I'd rank them 2nd best.