Just to get things back on track and out of rumors, here is a paper on oils for flat tappet engines, the need for ZDDP, the dangers of too much and too little, and clears up the false promises of motorcycle oils.

In discussing viscosity, consider it was written first about Corvair engines, which require the same things except in a 10W-30.

After reading through the 30+ pages, consider all the rumors and what you still need to ask or propagate.

Where a motorcycle oil (meeting MA2) is THE oil of choice is in the Mini with Automatic Transmission.

And synthetics will not run out seals any more than mineral oils. The thing is that if you were using a low quality oil, you have build-up of sludge around the seals preventing them from swelling as desired. Once you put in a high quality oil, mineral or synthetic, it will clean things up and may leak until the new oil gets to penetrate the seals.

I have used Redline 20W50 synthetic motorcycle oil in my car since rebuilding the engine, 8 years now, no oil leaks, engine runs very smooth I change it once a year which is about 3-4,000 miles.  It has the correct amount of zinc.  Has become a little expensive, but once a year is worth it for me.

Steve, that is just what i have heard from people who know more about oil than i do. I have not run/owned a re built engine personally long enough to say when and where do you stop using the extra Zinc after break in but like you have put a lot of miles on Mini's with used engines with no oil related internal engine or gearbox failures with regular 20/50 oil changes.

That being said it i cannot see where it would hurt a Mini engine using the high Zinc oils after break in so for those that want to go ahead. My two Sons and i are using Amsoil full synthetic in our regular drivers and their explanation of it makes sense but it is so hard for me to get my head around those higher mileage oil changes, i am at 8k now on a 15k oil change and i have to say it looks very clean so far so we will see. I run 20/50 in a 267k (original engine/trans) GMC truck which gets 3k oil changes and is used mainly for towing and get blasted all the time for it saying i should run 10/30 but it has worked for me for years so why change.

Just my 02c.

Mal, help me out here, the highlighted part about Zinc. Is it like mumps one shot and your good, once and done? I understand once the damage is done nothing will fix it. Does the need for superior lube and wear protection go away? Cam and lifter break in is a one time shot. Either you get it or you don't? I'm fishing the people I knew who would know are long gone. I'm sure I should look it up again. Steve (CTR) 

Edit: What about the gears? Don't they need high pressure lube? Can't hurt. 

It's amazing how many people don't know or disagree with that Jemal.

VR1 is the only oil that goes in my car.

 you mix synthetic with reg oil you are wasting your money. Once you mix it it becomes regular oil Don't waste your money

I qouldn't use synthetic.

....but, I regularly use Castrol 20/50 Grand Prix 4 stroke motorcyle oil.  ( if VR1 is out of stock ).  It has high ZDDP still...unlike GTX

Agreed, it seems to find a way out!  I don't think it will harm a Mini unless your engine is brand new. Even then it will only slow the bedding in of the new synchros, and possibly the rings.   I'm actually running Motorcycle synthetic 15W-50 (Lucas oil of all things!) in my 1380, and while the engine seems to "like it", much more is on the garage floor than when running my favorite Honda GN4 20W-50.

I think we'd rather change the oil more frequently, and synthetic is much more expensive.  Incidentally, extra zinc is only called for with a new flat tappet cam, and not "necessary" once the engine is broken in. 

I would not use synthetic in my mini. I guess I should say I should not have. I rebuilt the engine and ran it for acouple of months then placed on jack stands for a couple of years. While at the auto parts store I picked up a case (12 qts ) of oil and put it on the counter then went to look for a filter. When I got back the oil was gone and I grabbed another which was a synthetic blend I did not notice till I was done with the change and it runs though my car like a sieve. Steve (CTR)

 Hi has anyone used mobil 1 synthetic 20-50 oil in their mini ? when I first got  a very low mileage mini, i tried to use synthetic oil, only to have it come out the rear main seal. Since then, I've on used the 20-50 with hddp. I was thinking of adding a pint to a quart of the synthetic to 4 quarts of regular 20-50. anyone want to chime in here. thanks jim