Does this matter"!?
My Alfa 147 went into a local garage yesterday for an MOT,
It went no problems at all through the mot which is good.
But i didnt think to bring the bottle off selenia 20k i have in the garage down so they ended up filling it will valveline 5w-40.
It didnt bother me that much really but after having a quick look in the owners handbook yesterday it tells me that 10w-40 should be used in the petrol engines and 5w-40 in the diesels.
It does say on the bottle of oil they gave me that it is for use with petrol or diesel engines but as the oil grade dosnt match that quoted in the book will it make a diffrence at all??
It could just be me but im sure the car felt slightly slower when i took it out last night???