I have a 2004 S2000 and have 11,000 miles on it. I run synthetic 10-30. My question is if i only drive this car in the summer when it is hot and the engine obviously runs hotter can I use a 20-50 synthetic to protect the engine from viscocity loss?

 

You can, but oil will get to bearings slightly slower and the heavier viscosity may not give more protection given the clearances in this engine. Without access to any comprehensive lubrication studies for this engine most of us feel the best practice is to stay close the the recommended oil viscosity of 10W30.

 

Just use 10W-30 year round

And refer to the oil journals for all your oil-related questions: https://www.s2ki.com/forums/index.php?showtopic=195574

 

Thanks!

 

If you like to use synthetic oil in your S and you do not drive it in winter, 5W40 is actually better and it is also recommended by Honda, 20W50 is too thick for the S.

 

Thanks. Do you notice a quiter valve train as a result of using 5w-40?

 

any "effects" you "notice" will be perceived more than actual. the human senses are simply not keen enough to detect such changes. often people like to say they notice a change, when they are really only perceiving it because their brain thinks they should.

10w30 or 5w40 is fine either way you go. neither is going to make a difference in the temps you're talking about. also, if you're using synthetic I hope you're going AT LEAST 5000 miles between oil changes.

 

Yes. I plan to change the oil and filter every fall just before i store it for the winter. I drive between 5-7 miles in the summer. Thanks for the advice.

 

Would your username imply that you have some connection to Amsoil? And if so, wouldn't you know all this oil related stuff?

 

No. I buy the stuff and believe it's good stuff but don't sell it. I'm not an oil expert; at least not yet.