Anyone run Shell Rotella 15w40 in their 8.1, or am I the only one?

It's a little thick to run in a gasser. But I run 15w40 in all my company trucks its hard not to when you have a 500 gallon tank of setting their.

From the many pages of oil research that I have read, I would stick to the mfg suggested oil. Thick oil will usually do more harm than good in most applications that do not call for it, especially at startup!