The owner’s manual says to use 90 weight but the Genuine Honda fluid is 75/85. What do you use?

 

Redline 75W140.

 

Amsoil 75w-110

 

Motul 75W-140

 

Mobil One synthetic 75W-140.

 

amsoil severe gear 75w110 x 10 years with replacement q 8000 kms.

darcy

 

Any xW90 to xW140 is fine.

xW110 seems to be the sweet spot for street use.

The Honda stuff is meant more for their AWD transfer cases. Its really thin.

 

Honda does have the correct SAE90 GL5 oil but for some reason it seems to be hard to find in the US.
Do not use that other 75W-85 Honda stuff or whatever it might be.

 

The Honda fluid comes from their motorcycle division, it could be sourced from Honda if someone wanted it, but the Amsoil and Mobil1 offerings are easy to find and likely better.

 

I recall the "genuine Honda" differential oil is intended for front wheel drive cars and is NOT GL5 hypoid gear oil which is the critical spec. Many to choose from and multigrades are fine.

The spec for SAE 90 gear oil changed after the S2000 went out of production. It was split into a pair of narrower viscosity bands. The top half of the viscosity was split off to SAE 110 (which did not exist prior to the split) so you can use 110 and still be in the original spec. The SAE 90 on the shelf today is the thinner half -- but also still in spec.

The partial bottle of Amway Amsoil 75W-110 full synthetic in my garage leads me to believe that's what's in my differential which uses 0.78 quart. I know I used Lubrication Engineering previously but they're no longer GL5 certified. Big discussion a couple of years ago and the oil itself may not have changed just LE not jumping thru the certification hoop. Plenty of certified oils.

Maintenance schedule is two (2) years or 30,000 miles in normal service which makes it every other oil change for me the same as the oil filter.

-- Chuck