Quote Originally Posted by FormulaZR View Post
I use 0/40 for everything, including my boat. I use to swear by the German Castrol 0/40, the one that specifically says "Made in Germany" on the back. However, once I started seeing 0/40 Mobil 1 on the shelves for $25/5 qts, I just switched to it because of the price difference.
The 0/40 M1 is an excellent oil. People see the zero and get all jittery. I hardly pay any attention to the W number. If you don't live where it gets below freezing, its a useless number.
Interesting fact about the 0/40, its the oil Mobil recommends for non racing performance use in place of their racing oil. The other being the 15/50 if you need a heavier oil.
I only mention the 10/40 High Mileage for people that bring themselves to use a 0W oil.