Are there any straight weight synthetics? The previous owner was using a Shell Rotella T5 synthetic blend. I've got about 300+ miles on the truck since I bought it & she does no seem to have much if any blow by. Unknown actual engine mileage. Have I gotten the impression that switching between full synthetic & conventional is a non issue? I have always run Rotella T1 in both my gas & diesels but being out of the loop thought I'd get some more input ~

Thanks!