[gtfour43]

I dont know if it allows you to rev higher but I do know one thing. I took apart a customers engine once and he used nothing but Mobil 1 synthetic since he broke in the engine and it looked like brand new in there. The car had 130,000 miles on it already and it looked like some engines with 10,000 miles. I was shocked when I looked inside the engine. He usually changed his oil every 5,000 miles too not the normal 3,000 like with regular oil. Ever since I saw that I used only Mobil 1 in my cars. I also noticed that his car didnt have the usual oil leaks like other cars with that much mileage did. I think it also helps prevent the seals from hardening up and leaking. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'>