I use the Rotella 5-40 no problems. But Matt Letard is correct about the extreme heat. I ran it on the way to NH rally last year and got caught in 95ºF temps with bumper to bumper traffic on the expressway (with no exit or anywhere to go) for several hours and the bike got so hot I had to stop and let her cool, but then again so did every bike on the road too. But this was a very severe example of heat, never had any issues other then the one day. I will continue using it as I have been very happy with it.
