Thanks Richard!

That would be a good oil to use.
The exhaust norms generally are tied to the year of production. I had to get my Corvair exhaust measured, and it came within the limites for 60's cars. Rules in most countries started taking affect and some type of exhaust treatment in the mid 70's or so

The limit for my Corvair was  600 ppm. It has dual carbs, 6 cylinders. It came in with 319 at idle and 376 at 2500 rpm. So check the details of the local regulations. A good tune up should do it. I also used a bottle of Techron in the tank to help clean up the spark plugs, valves, carbs, etc.

Hi,Richard, apologies, just realised my previous post was the wrong article number. It should be this:

https://products.liqui-moly.com/touring-high-tech-super-shpd-15w-40-1.html

My next question is that if diesel oils would produce higher amounts of hydrocarbons in the exhaust compared to gasoline engine oils? Singapore where it’s constantly 30+ degrees celcius has implemented a 300ppm limit of hydrocarbons found in exhaust. I do not know for sure what constitutes hydrocarbons and understand there’s other possibilities of oil presence in the exhaust but I’m curious if there will be a difference.  TIa!

No problem with diesel oils in high revs. I run CI-4 in my Corvair and Renault, and friends with Mustangs. I prefer CI-4 over the CH-4 you posted, as it has better cleanliness and seal control additives.

Thanks Richard for the fantastic read. Been scouting around for a suitable CI-4 oil and chanced upon liqumoly Touring High Tech SHPD-Motor Oil 15W-40. 

What do you think of this?

https://pim.liqui-moly.de/pidoc/P000268/2474-TouringHighTechSHPD-MotorOil15W-40-28.0-en.PDF

https://products.liqui-moly.com/touring-high-tech-shpd-motor-oil-15w-40-2.html

FYI, I do drive my car quite hard and often rev up to 7k RPMs (once in while). I’ve been told that diesel oils are meant for low rpms and not for high rpms. Is there any concern?

This is an issue that isn't given the attention it deserves. I've switched oil brands a couple of times, but generally I ran the slippery-ist oil I could find (synthetic w/ ZDDP) and I was always aware that my synchros were struggling to keep up. When I wasn't on the track, I always rev-matched to give the synchros a break.

Jeff at Jet Motors mentioned in a video a while back that he found Amsoil Z-Max 20/50 seems to help with the synchro issue. I've been using it and the synchros do seem to do better, but not great—I still rev-match. I suppose I could use a less slippery non-synthetic oil for the sake of the synchros, but engines cost more to rebuild than the price of a few balk rings. 

Richard: Thanks again for your thoughtful advice.

I would stay away from that, as it does not comply with SAE norms. A 10W-40 must have at least a 3.5 HTHS, and according to that table, their 10W-40 is only 2.9, so it is labeled wrong. That could make it a 10W-30.

And the 20W-50 is 4.0 HTHS, which does pass the 3.7 minimum, but I've seen lots of xW-40 oils with 4.2. So it is more sluggish in flow, yet weaker in shear strength than many xW-40 oils. I'm not advertising Amsoil, but their z-rod 20W-50, for example has an HTHS of 5.2. And they even have 3.6 on their 10W-30.

Let's try this:

No, not VR1. I deleted my snapshot of the page, so will look later for it, although I avoid publishing names, for legal reasons.
Rotella 15W-40 is good, although a 10W-40 will flow better on startup. Much better than any 20W-50 for the majority of Minis.

That page does not open for me. Maybe for registered users? how about a direct link?

There is a highly advertised specialty 20W-50 oil for classic cars that is made from a group I base oil. That is the bottom of the pile in base oils.


Can you name that one....is it VR1?

Also....what's your take on Rotella 15/40 for a classic MINI (manual)

Richard,

Thank you for this article. Interesting read!

This is what I been using on my Minis, in 20w50. Currently being used on a 850 1965 Moke with unknown mileage original engine.

Castrol Grand Prix Motorcycle 4-Stroke.

www.arcticchat.com/forum/attachments/utility-performance-technical-info/104369d1123175230-oil-castrolgp.pdf

being driven only in good weather in Canada, so anything above 0C.

 

What's your take on it?

Regards,

Miguel

Yes, in a nutshell, stay away from anything with a SN in the label, especially with it on the left side of the "/", as that means it passes the slippery fuel conserving tests. This year, there are certain restraints as to when you can and can't put it to the right of the "/"after a diesel CK-4 classification, so in that case it is ok, as it meets CK-4, but wouldn't be my favorite.

Racing oils that "meet" SN, are tricky to categorize, as there are no concrete definitions as to what tests and limits they use. In general, it will be a SN with added ZDDP, but there is no rule, so it could be too slippery for synchronizers, or it might not be.

Base oil determination requires interpretation of the Safety sheets, and even then are not conclusive, as some brands do not say anything other than something generic. In general, if it says "Solvent refined", or "Distilled", it is group I. If it says "Severely hydrocracked", or Severely hydroprocesed", it is group II. But there is one brand that actually says Group I on their web page. I don't know why. For those that know, it is sort of like wearing the scarlet letter. Of course it would be nice if they just put the HTHS value on the spec sheet and we wouldn't care how they got there.

First of all, thank you for the detailed analysis and writeup. It was definitely educational and I appreciate the background and bit of data to support your recommendations. I have a few questions after reading the paper to help me put it into action in picking an oil.

> Never use an API SN rated oil.
> You do not want a common gasoline formula oil, such as SN.
You mention this a couple times, but I want to be clear on your takeaway. You said that the analysis takes you down the path of selecting a diesel formulation or a "specialty oil". Is a high-zinc, racing oil that "meets and exceeds API SN" a "specialty oil" in your mind or are you suggesting that we do not use an SN oil of any kind?

> There is a highly advertised specialty 20W-50 oil for classic cars that is made from a group I base oil. That is the bottom of the pile in base oils.
How would I find out what base oil is used for a particular product? I have looked at various product spec sheets as well as the MSDS for a few oils and don't see any reference to source or base for the products.

Thanks!
Scott

Thank you for your exhaustive thesis on Mini-specific motor oil—perhaps the most detailed I have seen! Of course I, and suspect many others were expecting you to make a recommendation for a particular oil. It was wise of you to avoid doing that.

Thanks
Looks like part of the link got cut off, here it is complete.
//www.widman.biz/mini_pics/classic-mini-oil.pdf

Not sure which other forum you mention. I posted it on Facebook and the Automini forum.

Great job - you mentioned a previous article on tappet protection - is there any chance for a direct link and are you going to post both links on the other forum also?

Considering the all the comments on oils for Classic Minis. I have put together a paper on the lubrication needs of our cars and the differences in different oil qualities and viscosities that you will find in different countries and stores.

I hope there is some information in there to help you when you hit the shelves for oil, or when someone asks you for a recommendation.

I've included an email for those who have more questions or doubts.

You can download it here: //www.widman.biz/mini_pics/classic-mini-oil.pdf