Best spark plugs for a S3c ?

[The Horse]

Hello
I've just run the plugs out to clean and regap and the ones fitted are NGK BPR6EFS. Are these ok ?

Also, do these look ok ? I've never seen them so "orange" before. The orange was easily removed with a wire brush

The Haynes manual lists only Champion RS9YCC7

Thanks
David

[zombeh]

I assume you use some sort of lead replacing octane booster type stuff? That's what the orange is.

[The Horse]

No, straight unleaded at it's a "c" so has a catalyst fitted.
Might have been rust as the car did very few miles for several years before the previous owner to me bought the car last year. The head gasket s are fine I think as it doesn't use any water there's no "mayo" inside the oil cap and the water system isn't getting pressurised beyond the normal thermal expansion.