Which Oil?

[twistysnovagte]

i currently have castrol gtx 15/40 in my car e16se(81k),its now due a change is the oil suitable which i currently have in ,or is there a more suitable oil which i can use?
was recently told(halfords) if i want the best from engine performance/durability then i should use the mobil 10/40!
not sure guys what do you recomend?

[Adam]

GM semi synth 10/40
?10 for 5L

[twistysnovagte]

where do i pick that up from adam?, as ive not seen it in halfords/motorworld is this better than the likes of your mobil castrol/duckhams?
i do have a genuin vauxhall oil filter,but was bought of ebay

[Adam]

A vauxhall dealer.
Or my local motor factors stocks it, so try motor factors too.

[Novasport]

Castrol is crap, I ran my Corsa Sport on it and it was never happy so changed back to Vauxhall stuff(Rumoured to be Shell oil).
I would use Vauxhalls own, Mobil 1 or Shell Helix. A friend of a friend works for an oil testing company. They say Mobil always comes out on top and Castol is not that good.