A friend of mine gave me a Mugen oil cap and radiator cap a while ago. I can deal with the radiator cap, but the Mugen oil cap seems to be made of some type of alloy that really heats up when the car is warm. I don't like it, as I have trouble taking it off when I need to add oil into the engine. The stock oil cap doesn't contain heat as much and it's easier to grip. Unless the oil and radiator cap makes a difference in performance, I don't think I want to keep it.

 

They are for look only, no performance difference.

 

Check the Mugen rad cap for the "lb." rating. If it's higher than stock, then you'll have a bit better boil over protection, however, the S2000 is not known to have cooling system problems for most driving situations. If it's the same, it won't do squat. Neither will the oil cap. They just look "different".

 

Aside from the bling look of the oil cap, I've read that some people have had bits of the plastic oil cap break off at the threads. Whether it fell into the valve train or not, I'm not sure. I'm not sure of the conditions at time of breakage either. But its nice knowing the oil cap you have is a lot less likely to break. I'd keep it.

 

It may because of something to do with this. It's not really an issue to do with the cap as such, but rather, more of an issue that the owner has overlooked something:

https://www.s2ki.com/forums/index.php?showt...hl=lost+oil+cap

 

My oil cap makes a difference to me, not to the performance.

 

How much,for your Mugen oil cap???
I'll take it.

 

Keep the Mugen cap and put a rag over it when you go to take it off. You will need the rag to check the oil anyway.

 

Sorry, if anything, I'd like to do this locally.

 

The rad cap boosts pressure from 1.1 bar to 1.3 bar in the cooling system which is supposed to aid in more efficient cooling of the engine. The oil cap is just a bling accessory, but doesn't offer any performance gains. If you like it, keep it; if not, sell it and make some $$.