Pretty much all motor oil manufacturers formulate their products using some form of additional additives. I'd imagine all these different oil manufacturers have to reach some sort of compromise between which type of additives will both work well, and also be priced to allow them to profitably sell their final product in their targeted price range.
I don't know a whole lot about any of these oil additives sold at auto parts stores
(like Dura Lube and many other brands) but I've done a lot of research on motor oils specially formulated to be used in high RPM racing 4-stroke kart engines.
After my research I came to the conclusion that if your running a stock kart/industrial type engine with the governor intact at 3600rpm, you'll probably be fine using whatever oils the engine manufacture recommends.
(and If you wanna pour in some extra additive that's truly a good product, it'll probably help the oil work better) But for these industrial engines that are race prepped to turn much-much higher RPM's, Its better to use some of the oil brands that are formulated/sold especially for 4-stroke kart racing engines.
Here's a link to few of those:
http://www.google.com/products?sour...sult_group&ct=title&resnum=12&ved=0CDkQrQQwCw
I've ran across lots of very credible sounding race kart engine builders/racers claiming that motor oils formulated to work just fine in a cars pressure-type oiling system aren't necessarily the best type for the splash-type oiling systems used in these high RPM kart race engines.
I don't wanna get into any debates on this subject here but If anyone's interested in doing their own research, I'd recommend they perform a search using the term
oils at this race kart site:
http://karting.4cycle.com/forumdisplay.php?f=81
(then just look for the thread titles that seem to be oil related) You'll run across several posters on that forum that are very knowledgeable/professional race kart engine builders that truly know what their talking about.
