I've made some minor changes this year to the engines this year.

First changed the t-stat for a 160 instead of 140, replaced the spark plugs and stepped up in heat range because of the bad fouling last year and finally switched oil from gulf mineral 15w40 to Royal Purple fully synthetic 10w40. I also moved to RP in the drives.

We will do a 15 hour change this year to see what the oil looks like but so far I'm happy with the RP.