An interesting thread that went a little haywire. I'll add my.02 . If sunruh says that he has evidence that a 1.00 quart of car oil will provide sufficient, quality, excellent, or just darn good lubrication for a certain bike application, you can bet your next pay check he has the facts available. The same as oil marketers wouldn't give out proprietary info on their products, he should not be expected to produce his information on research he has performed, that is his "proprietary" info. Harsh, but true... go pay for your own used oil analysis and find out what works for you.
As far as your YZ-F... modern MX bikes can turn 14k RPM's. IMO, an oil with extra AW additives will fare better than an SM rated oil, especially to protect the top end. The 20-50's and 15-40's will not be carrying the energy conserving labels, and may still have the extra zinc and phosphorous desired for protection, along with thicker oil films in the beginning for protection. The synthetic/conventional debate is moot when you are changing the oil every couple of hours. If you want a synthetic, go for it, but YOU will not likely see any benefit over the long haul in a modern MX bike, IF you maintain the machine as it is intended. For other applications and variables, there is a very good possibility that you would see a long term benefit from a synthetic.
The simple fact is that oil and fuel are the least expensive cost of any racing effort. The mechanics are into the engines every week, and in most cases, between the heat and mains. The engines are fresh on Friday, run maybe 2 practice sessions, 1 heat, and 1 main. There is literally an hour and a half on an engine over the weekend. Pro's like Carmichael, and Bubba haven't got a clue what is in the bike. For example, Carmichael was caught running an illegal fuel during a race this year. The absurd part of this situation is that he didn't purchase the fuel, or fill the semi's holding tank, or put the fuel in the bike. His job is to train, eat right and ride his butt off. It has been noted in interviews that he doesn't even clean air filters on his practice bikes, you really think he even has a clue what is in the crankcase? He could win with Wesson in the bike if it would run long enough to finish the race, because that is his job.. to ride better than the next guy.
It has been said over and over.. racing is 98% rider, 2% bike. Carmichael has won on Kawasaki, (sponsored by Bel-Ray and Maxima Castor 927), on Honda ( Pro-Honda and or Amsoil, depending upon who you listen to
) and on Suzuki, (again sponsored by Maxima). The debate can rage on forever, but it is unlikely that if a change were made from Maxima to Amsoil, Carmichael, or any other pro would begin to win or lose races.
