Hi guys, Thought I'd post this up and see what you think! I had Valvoline Synpower 5W-40 in my ute and ran up 215 rwkw (down 30rwkw but that's been fixed up now!), it was checked and was running that curve consistently, so it was rolled forward, dumped the oil and oil filter and changed to Belray EXS 0W-40 Superbike oil. It was warmed back up, checked the oil level and ran again pulling out a 226rwkw... That's a 10rwkw gain from oil.... And yes it was a change to thinner oil but not by much, especially at running temp. Interesting gain for the dollars huh...... Dave (I'll try posting the image right way up!)