Rotella T is the same thing. Rotella has a little higher parafin content than the other three, but if you're changing it often enough this won't cause a problem.

Rotella is probably almost as easy to find as Delo, but I started wtih Delo many years ago and have stuck with it. I don't like changing oil brands. I would rather keep the engine seeing the same stuff. Just my anal retentiveness I suppose.

Have a great day,