been searching loads and a few people messaging me asking.... but im getting told so many different things lol

my 2003 bug eye wrx is running 5w 40 oil at moment, and has done for a while according to the service book. the car had been remapped and things and proven to 281bhp.

should i change the oil to 10w 40 or some people even saying 10w 50. what would yous use?

 

Mine is running a backbox (so standard) and I run it on 5w 40 shell helix. What's the reason for changing viscosity?

 

Only reason im asking about poss changing it as so many people are saying different things. Some are saying it should be a different grade with the car running mods with that power?

 

anyone else...?

 

5W 40 is fine mate.I use it in my wrx.Imho unless its heavily modded or you intend to track it often best grade for a newage is 5w 40.Alot of people use 10w 50 and even 15w 40(50)(60)which is fine if heavily tuned or tracked,but for a standard or mildly tuned road car is counter productive in my opinion.But i also know oil is a can of worms and people will use what ever helps them sleep better