I've run both VR-1 SAE 30 and SAE 40 in my MG in the summer. The manual says either SAE 30 or 20W-50 depending on your local temperature.
Honestly, I'd probably run either all year if I didn't have to worry about low temperatures. Among other things, with the tired rings in that engine(I'm tearing down a spare engine now that I hope to have finished with the rebuild in the next few months) I got a lot less blow by. Also, in summer stop-and-go, my oil pressure seemed to stay a fair bit steadier than it does with 20W-50. I don't have a way of directly measuring the oil temperature in that engine, but figure that dropping oil pressure accompanied by rising coolant temperature is as good of an indication as any that the oil is warming up a fair bit.
If I read the datasheets correctly, VR-1(silver bottle) essentially has the same additive pack in both monograde and multigrade. Oil engines love the high levels of ZDDP in it, although catalytic converters may not.
I haven't used it in a while because, here, it's not uncommon to see sub-zero and over 100ºF in the same calendar year. The car is in an unheated detached garage, and I want to be able to start it at any time of the year. That means I end up dumping the monograde in October or so. Also, others have mentioned the cost-20W-50s are often on sale, including VR-1, while the monograde versions almost never are. Cost IS significant to me because even though it blows out less monograde than it does 20W-50, it's still enough that I rely on my inexpensively bought stashes of oil(or Supertech 20W-50 in a pinch) to keep it fed.
Honestly, I'd probably run either all year if I didn't have to worry about low temperatures. Among other things, with the tired rings in that engine(I'm tearing down a spare engine now that I hope to have finished with the rebuild in the next few months) I got a lot less blow by. Also, in summer stop-and-go, my oil pressure seemed to stay a fair bit steadier than it does with 20W-50. I don't have a way of directly measuring the oil temperature in that engine, but figure that dropping oil pressure accompanied by rising coolant temperature is as good of an indication as any that the oil is warming up a fair bit.
If I read the datasheets correctly, VR-1(silver bottle) essentially has the same additive pack in both monograde and multigrade. Oil engines love the high levels of ZDDP in it, although catalytic converters may not.
I haven't used it in a while because, here, it's not uncommon to see sub-zero and over 100ºF in the same calendar year. The car is in an unheated detached garage, and I want to be able to start it at any time of the year. That means I end up dumping the monograde in October or so. Also, others have mentioned the cost-20W-50s are often on sale, including VR-1, while the monograde versions almost never are. Cost IS significant to me because even though it blows out less monograde than it does 20W-50, it's still enough that I rely on my inexpensively bought stashes of oil(or Supertech 20W-50 in a pinch) to keep it fed.