Royal Purple XPR Racing Oil

[Spaniard]

Can you please elaborate more on what the difference is between regular Royal Purple and their Royal Purple XPR Racing Oil? What is the difference, is it good, bad? Also, why would they say:

"Royal Purple’s motor oils are API certified. For those seeking enhanced performance in high performance vehicles not under warranty, we recommend our XPR – Extreme Performance and Racing motor oil."

Not under warranty? why?

I use the 5w-30 Royal Purple oil and it is great stuff, need to under-go another change of oil and I thought I would check out their site to see whats new. Whats the deal with the XPR Racing oil?

 

[jdub]

Read the posts on RP in this thread:
http://www.supramania.com/forums/showthread.php?t=38768

RP oils have always been formulated for the racing crowd...the "regular" RP oils have an additive pack that meets API certification, but is still not as stout as other synthetic oils out there. Again, I'm not saying RP is a bad oil...it's actually quite good, but for the $$$ there's better available IMO.

RP's XPR line of oils are a true race oil. It's add pack does not meet the API requirements for a street motor, but is formulated to provide the protection needed for an engine that is run hard for extended periods. The result is the oil does not last as long and is missing additives to keep TBN at levels required for street use. Therefore API will not certify the XPR oils. Car manufacturers require API certified oils for use in the engines that make them go...failure to use the SAE grade/API certification voids the car's warranty.

 

[Spaniard]

very cool. thank you!