ah, okay, if you're blasting around at 100+ sustained, the 160f makes more sense under those conditions. (i sort of suspected as much....it would take an incredible cooling system to keep the oil at 140-160 around town.)
what are the specs on your motor? you might be a candidate for an auxiliary oil cooler (or two
) if you're on the track a lot. the old suzuki superbikes used to run multiple (as in upwards of 3 or more) oil coolers, and even then, they would run too hot and start to lose power.
oil tends to run hotter than coolant because it's in direct contact with the hot running internal parts.....oil is fed to bearing journals, cams, rocker arms, valves, tranny gears, sprayed underneath the pistons, etc. coolant basically just flows through water jackets in the motor.
and oil also unfortunately doesn't give up (or absorb, even) its heat as easily as water does.
if somebody could come up with an oil that is as thermally efficient as water without sacrificing any lubricative properties, there would be no need to have a separate (coolant based) cooling system.
[ 10-23-2001: Message edited by: jeff ]</p>