If you run an engine set up > for Super on regular, it will damage it. > > Just my 2p > > Martin > I disagree- an engine will not receive any damage running 87 instead of 93, 104, etc., OR the other way around. I have a extremely expensive Ford 390FE engine now a 447 after the stroker with the combination of custom pistons, cam and heads I chose, I'm supposed to run at least 97, runs best with 104-this is only because of the performance-not damage. The lower the octane you use for a high rated octane engine, it will run horribly and provide less performance (just ask a professional machine shop). Gasoline only enters the engine through the intake and valves (or FI system), sits on the piston until it explodes and then is gone; higher density (higher octane) the better performance as well as fuel economy youâ??ll have-no damage either way higher or lower. If you have a poorly built or designed engine that's going to start knocking anyway, manufactures will tell you to use higher octane only- to prolong the inevitable knock otherwise, they will tell you to use higher octane so youâ??ll get the performance (especially on turbo engines). Now if you were to run leaded fuel in an unleaded car then you'll have valve seat problems, if you run unleaded in a leaded car-you'll just have noisy valves, no damage. Also- Higher octane DOES clean some of your engine-it is a proven fact that the added detergents clean & keep clean parts of the engine. -----Dani B. #5003 To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/