Long time Shell Rotella-T user here...
Got no problems, and tear downs don't reveal any problems...
I get a little lazy at times and lengthen service intervals to 5,000 miles.
Yeah, I know...I know.
The car doesn't get run hard nowadays.
1987 Turbo II
13BT
Haltech E8
Last put down 240hp at the wheels on a DynaPack dyno
Daily driver
10 - 12psi of boost max
Premix'd with Valvoline Multi-use premix in the blue bottle
-Ted