Engine oil choice

Engine oil choice

Postby p2roverman » Wed Mar 06, 2019 6:40 pm

I've been advised there are two types of so-called 'classic' oils, that with detergant, and that without. Note that not all companies may offer this choice, but Millers Oils do.
The theory is that their 'classic' oil has detergant which keeps contaminents in suspension until the oil goes through a micro-filter, as found on a P3 and all later models. (Oil in a P3 and early P4 wil take longer to be fully cleaned due to the filter being only a bypass type). All standard modern oil has detergant, especially that specified for diesels.
Their 'vintage' oil has NO detergant, so that contaminents will drop out of the oil and settle in odd corners, eventually buiding up into a thick layer of sludge in the sump bottom, but importantly, not being continuously re-circulated through the engine causing damage and wear.
Something to think about when next buying oil for an engine like a P2 which only has a basic mesh filtration. Duckhams 20/50 perhaps not being the best universal solution!
Posts: 60
Joined: Fri Aug 28, 2009 1:52 am

Re: Engine oil choice

Postby Geoffrey » Fri Mar 15, 2019 9:22 pm


Choice of oil for old vehicles seems to be a never ending source of differing opinions. I have several classic motorcycles as well as my Rover 12. None of these vehicles have what you could call an oil filtration system. I have decided to try and take advantage of the benefits of a modern oil. I have a Sunbeam S8 motorcycle that has an oil in the sump engine like a car. Recommended for the bike is straight 50 engine oil. I have realised that when it gets really hot it thins out to the consistency of water but when cold was quite thick and heavy. So probably lacking in good lube qualities when hot and takes too long to get to the bearings when cold. Millers do a Classic Sport 20/50 engine oil in semi/synthetic or fully synthetic form. It is mildly detergent I believe. This oil is much better at maintaining viscosity than the old oils and is thin enough to get to bearings quickly. I think as long as the oil is changed regularly then it will not get too dirty and the amount of contaminants in it will be at a fairly low level. Millers brand this oil Pistoneeze and they recommend it for classic post war vehicles. Indeed the fully synthetic version is aimed at classic cars used for racing. This is what I have put in my Rover as well as the Sunbeam.

1947 Rover 12
1952 Sunbeam S8
Norton International Special
1947 Norton 16h plus Watsonian Monaco sidecar
1961 Royal Enfield Meteor Minor
2018 Royal Enfield Himalayan
1999 P38 Range Rover
Posts: 20
Joined: Fri Feb 15, 2019 1:19 pm
Location: Tunbridge Wells area

Return to Wilks' cars P1 and P2, thats cars up to 1947

Who is online

Users browsing this forum: No registered users and 0 guests