A lot has been said about the 912uls cooling. I have had CHT temps over 240degF for over 2 years in the summer. Not to red line but Not Comfortable to fly any distance with. I have over 1100 hours S7 and my Evans "lifetime" coolant and was ready for a change. I read an article, (I think by Roger) about using 50/50 Antifreeze instead of Evans would bring the temps down 25 to 30 degrees.
It works!!!! My CHT and Coolant Temp are down 25 degrees today with the same OAT as when they were in the 240 range. I am ready to take a summer trip again. BTW, I chose Prestone DexCool (Orange).