I thought I understood the fuel rating system (this bloke Ron measures it, apparently.....) but was somewhat confused when reading a letter in this month's Car magazine.

The letter-writer claimed that there was no need to use SUL for any Japanese imports, as the highest octane rating sold there was actually 93 octane rather than 100. IIRC, it was something to do with differing ways of measuring the octane level in Euope and Japan, so 100 there is 93 here. Or something.

Had this bloke been taking hallucinogenics, or is there some vague element of truth to this seemingly half-baked assertion.

He backs up his claim that SUL is totally unnecessary by stating that he's run his Jap-import Supra twin-turbo on NUL for a huge mileage without any problems.

Thoughts, anyone?

Poor deluded fool has been running reduced boost on his Twin turbo for along time now...what a waste !

Right, from what I know (which may be totally wrong), it's measured differently in the states, but in Japan they use the same system as here, and they do indeed have 100RON.

And Trgger, he's not running reduced boost, the timing as merely been retarted appropriately. You can run those on anything down to 91RON on our scale (IIRC), and still get full boost, with minimum power loss. It is recommended that he use SUL though, especially when modding.

Been there, done that!