Our L15 motors are actually designed to accomandate 5w-30. 0W-20 is used mostly for market appeal.


I have used 0w-20 in a 200k d15b2 from the old days. The same motor also saw 10w-40 at some point.


Trust me when I say I did not know any difference from teh driver seat between the two "extremes". I did not see smoke when I ran the 20 weight, I did not feel any slugishness running the 40 weight.


Hell, I had a buddy who ran 20w-50 in his Ford Probe (mazda V-6) to remove the helicopter noise that happens with those V-6s during higher mileage.


Being that you are in an area with no chance of cold extremes, you have the ability to run whatever you want.

Here in Wisconsin, the thickest I would ever run in the fit is 5w-30

 

The last oil change I used Royal Purple 0W-20 synthetic.
For the oil change I did today I used Amsoil 0W-20 signature series 100% synthetic along with an Amsoil oil filter. It's guaranteed for 15,000 miles with the filter they had and I plan to go that long before changing it again.

I also did 2 drain and fills of the auto transmission and used Amsoil signature transmission fluid. It's supposed to be compatible with Honda DW-1 fluid. I'm hoping that the combination of these two premium fluids will give me a boost in gas mileage, but we'll see.

I bought a case of each, so I'm set for 2 more fluid changes.

 

No fluids will give you a noticable gain. The numbers might be there, but in all my driving and mechanical experience, good fluids simply meant gaskets and seals lasted longer, noticably less wear and tear, and generally a quieter motor and transmission.

I would be surprised if you saw a gain of over 20 miles per tank.

Your motor and tranny will love you long time though lol

 

I'm planning on keeping this car for a long time and 200,000+ miles, so if that's all I get out of it I'll be happy. The extended change intervals will be nice also.

 

take an oil sample every 4-5k miles and send it in. Takes around 2-3 weeks to get results back. It will tell you if it indeed is worthy of waiting 15k miles, or if the motor design simply doesnt like it, regardless of oil capability.


For lack of a better phrase, one size doesnt fit all. Motor A might be happy with 15k miles on the same oil that Motor B only likes to around 12k miles.