Oil weight for 560SL?

[bhatt]

Hello all,

I have an '87 560SL (M117) and live in Canada (Toronto).

What weight of oil should I be using in this car? I'd like to use the same grade all year round if possible.

I know many people use 20W50 in the summer and that should be fine here (it is usually not much higher than 80 degrees fahrenheit in the summer here, but can go to 90-95 for a week in the summer if we have a heat wave)

Our winters can get as low as 0 degrees fahrenheit .. can I still run 20W50 for the winter?

I'd can buy my oil by the case, so I'd rather buy one kind if possible. If not, would it make better sense to buy a case of 20W50 for the summer/10W40 for the winter??

Neal