Eric...In my CK30, it doesn't seem to work that way.....I wrote this in another post:
"So last spring, Rotella ran a rebate offer, and Walmart a special, and I picked up a couple of jugs. With 479 hours on the clock, I made the switch. Everything works fine, no leaks, drips, or oil consumpsion issues, but there is a noticeable decrease in oil pressure when operating at sustained rpm for 2 or 3 hours straight.(as in mowing or the like) I have both oil temperature, and mechanical oil pressure gauges mounted. Delvac always provided 54 psi, at 2150 rpm's. with oil fully warmed up to 180*. It takes a good 45 minutes, on an 80* day to reach that temp. In the winter it will never come close to 180. This summer, with the Rotella synthetic, I'm only getting 50 pounds of oil pressure at the same 2150 rpm, with the oil temp at 180*. Next oil change, I'm going back to my Mobil Delvac 15w/40....advertised as "the million mile motor oil", and time and time again, proven to be correct in over the road trucks."
I'm not saying that T6 is crap....I do run it in my 2011 Camaro. I just prefer the 15w/40 in my tractor, lawn mower, motor scooter, and all 3 of my motorcycles.