I have been reading on another forum about high detergent levels may be good for longer lasting oils, but it also removes the ZDDP that is needed for high performance engines. So it's really a balance of the two additives or like a lot of things with engines.....It's a compromise between the two. Would seem to make sense when you look at Joe Gibbs Racing Oil for break in. Here is what their web site has to say for their Break In oil. Product Features: * Used by Joe Gibbs Racing to break-in and dyno all their engines * Petroleum oil provides the highest levels of zinc and phosphorus for flat-tappet engines. * Additive package promotes ring seal and provides maximum protection available for cams and lifters during initial break-in. * Requires no additional additives. * Good for full power pulls on the dyno, one night of racing or up to 400 miles on the street. * Provides maximum compression and generates maximum horsepower. * Compatible with methanol and high-octane race fuels. http://www.joegibbsdriven.com/products/breakin/br.html viewtopic.php?f=54&t=10186&p=40285#p40285 Any opinions or comments ???