Sully, I got a block heater with my NH TC48DA. My neighbor saw it and bought one outright for his TC35A, it was only $20. I've bought also some of that Wally world Rotella 5-40 "synthetic". Because it's easy to find. Now I also bought a 5 gal pail of NH Mastergold Ambra 10w-30 diesel oil before I found the Wally world 5w-40. It was only $2 qt. in the 5 gal pail. Pail was $40 of course. I was concerned about the cold weather starting also. Remember even tho the pour point may say -40F, the pumping of the oil is usually 20 degrees higher. So a -40F pour, is really a -20F pumping, and even then it's a tough haul for the oil pump. Better to have an easy flowing oil for winter. Rotella post their specs on the web. I had to contact an Ambra sales rep, at the Speciality oil site. Even then he only gave me exactly what I requested, one being the pour point, and the other being the TBN, which was an 8. I believe that Rotella is 11.5, and Amsoil is a 12.2, and another oil, which slips my mind was a 12 also. The TBN is the ability of the oil to handle soot, and neturalize the acids that burning diesel creates. The sulfuric acid may not be much of a problem as the sulfur content is reduced in future fuels. The piston injection pumps tend to handle the lack of sulfur better than the rotary injection pumps. IH3444