Castrol or Shell M only in my engines.

I trust these companies products more than some of the "bathtub" refineries.

I will only use Shell M in my air cooled Yamaha race bikes. These put out around 76 ~ 80 hp as a 350cc which is considerably more than they ever did on 115 octane (Methyl Benzine added) or the old leaded avgas, while it was available.

The Castrol lubricates exactly the same as the Shell, however, when racing in wet conditions, for some reason which has been explained to me, but that was years ago and long forgotten, the Castrol can cause the water in the air to affect the anodised aluminium throttle slides and they can stick open. Not good.

We still use Castrol R30 and R40 in the gearboxes. When something that is commercially available and better can be found, sure, I will use it. We did, back in 1994 ~ 1996 have access to Elf X-2560, which was developed for the Williams F1 engines. The problems were, it was VERY expensive and even more alarming, carcinogenic.

So, put me in the Castor Oil camp, I think I'll stay there, thank you.

Peter Hinton