Technical 5w40 vs. 10w50 ???

[MRoland]

I have a T-jet 120hp with Slenenia K 5w40 oil.
I know the abarth T-jet 155hp need Selenia 10w50 abarth oil.

So if I fit a vl36 turbo and it will around 150 hp, later with a modded map around 170hp will I need 56538809 oil?

I have a lot cold start, and a lot of short ride. Around 4miles.

5w40 has better cold engine lubricating, and 10w50 takes much more heat?

Help me choose please!

 

[Avocet]

Why not go for the best of both worlds with some 5W50?

http://www.opieoils.co.uk/c-1039-5w50-engine-oil.aspx

If not, I'd go for the 5W40. Most of the wear to an engine occurs within the first few seconds of a cold start. A good quality modern synthetic (fully synthetic that is) should be able to take the pain quite easily at high temperatures. If you're really bothered, maybe change it more often that the service interval suggests. They don't need much oil rpessure to prevent damage, so I wouldn't be too bothered about it thinning-out wen it gets hot. I'd be much more worried about starving the turbo bearings and top end on a cold morning.

 

[MRoland]

Thank you for the help!