I was passed a few weeks ago on the A34 by a Mini Sprint on the way back from Beaulieu with the distinctive Castrol R smell.
That was me
)
As far as Castrol R being illegal for the road, what a load of cobblers!
The only reason it isn't used more is that;
1) It stinks, for some strange reason not everyone likes the smell.
2) Historically it has been very expensive when compared to mineral oil.
& 3) As has already been stated it does tend to oxidize quickly compared to modern mineral oils.
Having said that as long as you change it reasonably frequently (around every 1,500 - 2,000 miles) and allow it to warm up on cold mornings, remember it's a monograde oil so is a lot thicker when cold than when hot, you will have many years happy & smelly motoring.
As far as protection is concerned, mineral oils have certainly improved over the years and the protection in extreme conditions is in all fairness as good if not marginally better than R nowadays. The film strength & resiliance of R is still superb particularly in the Mini with its oil being shared by the engine & the box.
Running R is a bit of a labour of love nowadays, but it is still a cracking oil that does what it should. I use it because it reminds me of my youth & it still works well if you know how to use it.
Finally, you can't mix R & mineral oil, if you do the whole lot sort of curdles. An engine run on R must be built using R. However for the authentic wiff, stick some in your SU dashpot or maybe a couple of capfulls in your tank (as long as your C/R is not too high). You get all the retro whiff without any of the aggro.
But remember to watch out for PC plod
Ha, ha, ha!
Mark F.
Very nice car indeed, the Castrol R smell really adds to the overall feel of a car like that.
[? Fly-off handbrakes illegal because they allow "fun"??
yep, been told that too
Ha ha, really. alot of cars had them as standard. Really wish people who know nothing about things like these wouldn't bother commenting.