Originally Posted By: NHHEMI
Originally Posted By: StevieC
To touch on NHHEMI's point...
With Amsoil they claim to meet all the spec's under the sun but only one of their oils is tested and certified by the API and that's their XL-7500 series oil. All others is done by their own in house testing and verified by a 3rd party lab.
I still use it with confidence because the company knows how to make certified oils as shown by their XL series, but chooses to put this "Certification" cost into the oil rather than in the pockets of the API cronies. I like this way of thinking...
A company that has been growing exponentially and beating sales forecasts for over 30 years is enough evidence for me that they know their stuff, and gives me the confidence to use their product and sleep easy at night knowing my engine is extremely well protected even with long OCI's.
Not always is the API certification the deciding factor. During the warranty period of your vehicle maybe, but after that I toss it out the window and go with what I feel is the best oil for my application regardless of API-certification approval.
Now I'm not saying RP isn't as good, as I have only tried it once, but for the price which is almost the same I feel that Amsoil is a better bang for the buck!
You do realize that RP's regular SAE oils are API certified right? It is their XPR Racing oil that is not API certified. Mostly SL but a few SM. Kind of sounds like you think they do not offer any and that is why you think Amsoil is better.
RP does not submit for mfg standard certifications for the reason you say Amsoil does not submit their other oils for API certification. Most of their certified oils are only to API SL because they feel the ZDDP reduction required for SM makes the oil inferior to SL.
Oh no... I know that their oils are API certified... I was talking about Amsoil. Sorry for the confusion.