5-30? or 10-40?

Raceline recommended to me "Millers Oils CFS 10w-40 Competition Full Synthetic Engine Oil -5 Litres" - not cheap though!

See this link not tried it but I am pretty sure it will come back with 5w30 as far as I known no manufacturer recommends 10w/40 for petrol engines used in Europe these days it is usually 5w/30 or 5w/20 ----------------- 5w/40 or 0w/40 should also be OK.
http://www.castrol.com/castrol/iframe.do?categoryId=9024084&contentId=7044829

[Edited on 21/1/12 by britishtrident]

try the comma web site.
would use 5-30 semi syn myself, but most say 5 -30 fully syn now for duritec

Various sources will put it as 5w30 but as I say Raceline (Chris) recommended 10w40 for harsher use (than you'd get in your standard Mondeo).