On me astra I'm currently running Castrol RS 10/60. As i'm having mofo problems with money at the mo I can't really afford to use it anymore which is a shame because it's a really good oil . I'm planning to change to Vaux's own 10/40 'cause it's cheap as chips.
Look on JohnA's site Matt, lazy bugger!! erm, valvoline stuff sorry forgot to dsay £13 5L
I get parts at trade price so can buy most stuff dirty cheap so if you want a load of them let me know and I'll buy a few for you next time I'm restocking.