39 dodge d11 oil?

Hey guys. Just wondering what should be the recommended oil for these 218ci engines. Straight 30 weight non detergent or a multi viscosity with detergents. Need to change oil and am curious which would be best for car.

I'm either getting straight 30 non detergent or probably 10w-30 with detergents.

Just need to know which is recommended.

I use 30 wt non detergent

I use 30 wt non detergent

Depends on your engine. . . If it is fairly clean inside then I think the case for using modern multi-viscosity oil is very good.

If it is worn and full of sludge then there is an argument for using a straight weight. But there is also a pretty good argument for at least pulling the pan and valve covers and cleaning out the sludge.

For what it is worth, my '33 Plymouth has a very similar engine and the instruction book says

Cleaning Oil Pan and Screen

At least once a year, preferably in the fall, the oil pan should be removed from the engine and thoroughly washed. The oil strainer should be removed and washed at this time.

Doing it once a year may have been necessary back in the days when everyone used straight weight non-detergent oil and 90% of the road mileage was unpaved. It is probably not required nowadays but doing it at least once when you get the car is a very good idea as it also allows you to inspect the bottom end of the engine.

And if you've done that then you've removed the gunk that people who recommend non-detergent oil worry about and you can get the benefits, like better start up lubrication, that multi-viscosity oil gives you.