Suitable oil

[r.tec]

https://www.enginelabs.com/news/synthet ... -debunked/

[Exminiman]

https://www.enginelabs.com/news/synthet ... -debunked/

Thanks for sharing, but to be honest I dont think the article really clarifies anything, except the idea that synth oils can be used in older cars. Maybe they dont consider it matters, but no reference to “flat tappets engines” either for or against.....

Seems the author is no more qualified than you or me “ Greg has spent seventeen years and counting in automotive publishing, with most of his work having a very technical focus. Always interested in how things work, he enjoys sharing his passion for automotive technology with the reader”

Is there anyone on here who is qualified to shed more light on the viscosity or ZDDP question?

[timmy201]

There's a paper here written by a mini-owning oil engineer. It compares modern oils, has some info on what old oils were like & gives some recommendations based on the needs of a mini and the oil clearance specs etc

https://www.widman.biz/mini_pics/classic-mini-oil.pdf

[Peter Laidler]

Dear o' deary me..... this subject is destined to run - and run and...... Maybe the subject of 'what oil....' ought to be put in the same category as religion, politics, waterless-coolant and silicon brake fluid. Not permitted to be discussed in the Junior Common Room, the Mess, the Lodge, reunions, forums, soshal-meja or in polite company anywhere.

Everyone has an opinion. And according to some experts, even the manufacturers choice is simply their opinion. Nope, I don't get it either

[111Robin]

One thing he says is he expects 500,000km from an engine before rebuild. How long does he expect to live ?. That would currently take me 150 years. It's all very interesting granted but ultimately it's a rabbit hole and life is too short to be that bothered about it. Someone should do a report on which oil is best for a car sitting doing nothing for most of its life, that would be far more relevant.

[timmy201]

I will say after reading his article the main thing that stuck out to me was that I was having a delay on the oil making it to the top end of my engine. I was using the usual 20/50, so when cold it's pretty thick and my engine is fresh so it still has tight bearing tolerances. I have the 70psi oil pressure relief valve and about 80% of the time it was pegged at 70psi, so most of the time the thicker oil wasn't adding any pressure to the system.

I decided to try a 10/40 that met all the specifications for a mini, the right ZDDP and none of the additives that will cause issues with the synchros. Now I get pretty much the same oil pressure (within about 5 psi when it's not pegged) and the oil gets to the top end much quicker. It’s only been a couple of oil changes, but so far I've been satisfied.

Of course, just like biscuits, many people like what they like and have no reason to change and that's fine.

Interesting to see what the 1966 manual (AKD3860G) suggests:

oil.jpg

1961

1961.jpg

1967

Screenshot 2022-06-11 144546.jpg

[Dearg1275]

I bought a new Audi in 1984. Mobil 1 fully synthetic oil was fairly new on the market then. I was surprised at its first service by the recommendation of the Audi dealership to replace the gearbox oil with Mobile 1 engine oil. I went along with this and the gearbox stayed sweet for the 300,000 miles I kept the car. Shame it rusted away! Perhaps mini gears are fine running in synthetic oils.

D