[GarysZ24]

Bill, I'm glad you spoke about Royal Purple Oil as you did in your most recent post. My engine builder was a RP user and after I broke in my motor I tried some of it. Back in the 90's it was nearly $9.00 per quart (OMG), while the others were between $2.75 & $3.75. The John Force factor had some to do with my switch, but I mainly went to Castrol because the originally were advertised as the ideal oil for smaller engines (which I certainly have, compared to the behemoth big blocks about Stock Eliminator), and their contingency postings being unequalled by the other products out there (especially in years past).

Bill you and RJ both hit the nail on the head, that testing is the way to know which one is best for your given combo, and that what may work for one engine combo, might not be best for another. That said, I feel that I improved by going to Castrol, and I certainly liked their involvement in all levels of NHRA drag racing (national event contingencies (class wins as well), divisionals, and et bracket finals), which most of the others don't equal. Given that I'm running a motor that was built 13yrs ago, I have to also give credit to the additive "RESTORE", because the tandem has helped my V6 keep on running (good & competitive) for all of these years...thus Castrol can't be all bad! However, when it comes to my truck Valvoline's "Dura Blend" oil I've used since my truck had 15k on it, and my inline 5cyl engine still hauls the Z24 and an 18ft flat bed car hauler around with 87k on it now ('Vegas is looming for it again). If Valvoline was as in to the contingencies as Castrol is/was then I'd switch the Cavalier over to them also. My .02 worth....