I’m due an oil change.

Currently has 15/40. Car is usually in New York.

Since sorting out a load of vibrations and rumblings, rear bearings, feathered tires, I can actually hear my engine.

I think I’m detecting some cam noise. Very feint.

It’s cam side of things because it seems half the rpm of engine. I want to protect that situation as much as possible.

I’m in South Carolina for the year, what would be a recommended weight for the summer?

 

You can keep running 15-40. My D2 spends a fair amount of time in SC and I have never changed out my 15-40. Car resides in Fairfield County, CT.

 

ok. Solid. Appreciate it.

 

I use Mobil 1 High Mileage 10w40 all year here in South Carolina.

 

i was reading a P38 forum and most of the UK owners run 20w50 in their engines.

same engine as our D2s and considerably cooler climate than the Southern U.S..

 

Oil always going to be a struggle I run Royal Purple 10/40 HPS the Disco is running nice and quiet - other than the exhaust leak.
The Brits run 20/50 in pretty much all versions of the Rover V8, when the engine was designed, single weight oils were common - my oil pressure is good so I do not see any need for any higher than 10/40

 

20W50 is a good choice but not sure worth the cost premium over 15w40 or 10w40

 

My first D2 I ran 15w40 in the summer and 10w40 in the winter. That was the only D2 I ever had this issue with, but I noticed on cold days in the morning, first start, I'd have a bit of clatter for a few seconds with 15w40. 10w40 resolved that.

All the rest I've run 15w40 year around.