If I'm interpreting this chart correctly it looks as though it says that 5W-40 is the ideal choice for the S2000 and NSX:

http://www.honda.co.jp/parts/hop/oil/next02.html

Can anyone with translation abilities provide further details? I've tried a babelfish and it won't take.

Does anyone currently use a 5W-40 year round? I know it's an option available to us in the owner's manual but I found it interesting that Honda appears to prefer it over 10W-30.

 

moving to UTH

 

Thanks Wisconsin.

Wasn't sure whether to put it there or here but I'm sure more will see it here.

 

I use 5w-30 year round, but have yet to drive my S in above 85 degree ambient temps.

 

i figure i live in texas so ive heard its best i use 10w-30

 

That would be the best weight for a climate such as Texas.

 

How similar is Japan's climate to the US's? How about gas mileage requirements? Maybe the S2000 wouldn't meet LEV standards with a 40 weight oil such as 5W-40.

 

Some peeps use 5w-40 here in the states. 5w-40 has the flow ability and efficiency of a 5w motor oil and the thermal break down protection of a 40w motor oil.

5w-30 is good enough for me. I don't want the extra additives of the 5w-40. If I feel I need a heavier oil due to higher ambient temps, I will go with the 10w-30.

 

5W-30 will flow better at cold temperatures, and 10W-30 will have less viscosity extender additives. Unless the climate requires it (temperatures regularly below 20 deg. F), I'd use 10W-30.

The climate in Japan ranges from sub-tropical conditions in Okinawa (similar to Florida) to temperate conditions in northern Japan (similar to the mid-Atlantic states). If you are in the mountains, it gets colder there than lower elevations at a similar latitude.

 

The Japanese engine (F20C1? vs our F20C3? - I think I'm not sure about designations) also has a slightly higher compression ratio. Maybe that has something to do with it.