THought I'd throw this out to the masses and see what people think. This is not about brand or type, this is about weight/grade. I've been running 10w40 in my SM610 (98% street duty) all the while of 54k miles. With the new engine now in it, I wonder if it would be better to run 0w40 (like I do in the dirt bikes)? Or stick with 10x40.
40W is 40W. Only difference will be how quickly it flows to the bearings at startup. In my opinion, fast = good.
The lower you can get the cSt at ambient, the more flow you will have at start up. For example, 10W40 may start at 110cSt while 0W40 is 72cSt. Both will take some time to heat up and become 13cSt at 100°C. The 0W40 just gets there sooner.
Kinda what I was thinking...*but*...It was hard and expensive enough for the engine job this time (got lucky and found a complete new engine for less than overhauling my old transmission), in another 50k miles I reckon it's going to be even harder and more expensive. Just thinking about staving off any extra little bits of wear that I can.
