Sorry, Another Oil Question

I have an E9 with a complete engine rebuild and have been breaking it in with
conventional oil. As an oil choice from here on in, should I use a Brad Penn 20/50 semi-synthetic, or Mobil1 full-synthetic?

Thanks,

Pat

I would avoid full synthetic oils in pre-80's engines, especially if your plans are to drive the car mostly on weekends.

I'd go with a quality oil from a major producer, that has appropriate viscosity numbers for your climate and is readily available. After that, most synthetics probably so far exceed the state of the art in 1973 that it may be irrelevant which you use.

Manufacturers post test results for their oils, though they may not be simple to find. A little knowledge about what you want your oil to do is useful, and there is a very informative article on the qualities of oil at www.bobistheoilguy.com

The supposed potential for leaks resulting from synthetic oil should not be an issue for a recently, competently rebuilt engine. You'll find out either way: whether it leaks or doesn't.

Pat,
If you trusted the mechanic enough to rebuilt the engine, you should get him to recommend the oil...
Stan

Stan said:

Pat,
If you trusted the mechanic enough to rebuilt the engine, you should get him to recommend the oil...
Stan

Click to expand...

Could not be a better advice.

With a rebuild I have typically been advised to run non-synthetic for a specific number of miles to bed the rings. Then I have gone pure synthetic after.

That said...I gotta think with the new oil technology there may be a break in product which tops the semi old school approach.

I've used Mobil 1 15W-50 in M10 and now M30 motors since the early 80's with absolute success.

On my old 2002 - I pulled the motor out for an unrelated issue and (since it was out) removed the pan to 'look' at things.
The pan and lower end were spotless inside - the fella I was working with (local 2002 Guru) was shocked at how clean everything was. I had about 50k miles and 15 years on the motor at that point (I rebuilt at 180k, the vieweing was done about at 230k).

I use Mobil 1 5W-40 in my E38 as well as in my Porsche 911 (997).

I have 250k in my 2001 GMC Yukon and have used 5W-30 in it since day one - and have not had any issues with that truck at all.

I had 300k in my old Mercedes diesel using Mobil 1 as well and I could go on with all the cars/trucks I've had - 1.7 million miles across them all and all of them on Mobil 1 products. The only engine I rebuilt was the 2002 - and I did that because I wanted to, not because I had to.
From my experience - Mobil 1 is a great product, but I also say that the best thing to do is to do regular changes with whatever you choose to use. And... I think it is good to be consistent with brand and weight.

YMMV of course

Good luck

Oil Choices

My oil of choice is Valvoline VR1 20W-50 Racing Oil. Prior to using that, it was Castrol GTX 20W-50. I use the same oil in my E9 and both of my 2002tiis.

oil choices

I suspect it is possible to overanalyze oil choices until just opting for the one with the most outlandish claims. The M30 is vintage. New synthetic oils are great for the new era of motors, and perhaps even our Coupes, but over the years many M30s have lasted many, many miles on old dino oil. It is correct that back in the day, dino oils offered more zinc, and I feel this is what our blocks crave. My choice is Valvoline VR-1. 20/50 easy to find, higher in zinc.
Mike