how many miles on ride I have been debating on wether to use auto oil or stick with moto oil. I have been doing research for about a year and a half on all the pros and cons, then I ran up on a post of this guy had a cbr 900, the first day he got it, he put regular castrol auto oil in it, ran up to 100,000 miles, then raced it awhile, then at about 200,000 got him another, but still kept that one and said it still ran like the day he got it. So my mind is set, I use castrol gtx 1040 in winter and 2050 in summer, in all my bike now and cars. Hope this gives you some insight on all this ( you are only supposed to use moto oils in motorcycles) crap. Of course the dealers are going to tell you to use this, because they make money off the high price moto oils. Like I said I have done research on this, about the additives, ingredients, talking to people and conclusion is you can use automotive oil, just pick the right one.