Few questions. I stopped by the Honda dealership to get a diff oil change. But before they touched my car, I asked what they were going to use, and they gave to me Castrol Hypoy C Gear Oil 80W-90.

It says in the back "Exceeds API GL-5 and MT-1" so does this mean this Castrol is ok?

my car is a '07 completely stock. I know many people use Mobil 1 75W-90 and LE607 (seems to be the popular choice) but was wondering if this gear oil will work just as well.

The bottle specifics that this oil is for "motorcycles, atv's & scooter transmissions".

And when I did a search on Castrol Hypoy C, no one seemed to have mentioned it. So I justed want to run it by here before I mess up my S2K (first gear oil change).

Thanks guys for help

I'm going to the dealership tomorrow afternoon so please let me know oil experts!!

 

Never heard of it. I use redline....and I do it myself because it doesn't take long at all.

 

I use honda, the car was made by honda and the oil was designed for honda's, so use honda.

 

Honda does not make a differential fluid for the S2000. The dealer outsources. Honda's diff fluid is VTM fluid which is NOT correct for S2000s. So you can't use honda.

OP: If the oil says it's a Hypoid lube and it meets or exceeds GL5 cert, and its 80W-90, then it's the right oil for the diff.

Synthetics are known to work better usually. Since you only need 0.8qts for the diff, ponying up for 1qt of the expensive stuff isn't a big deal. This is why people buy synthetic.

The spec from honda is a SAE 90 oil with GL5 or better cert. and it must be a hypoid lube (i think anything that says GL5 is hypoid oil though). Hypoid oil has a "sticky" additive in it for use in hypoid gears. Hypoid gears have a beveled shape and have a lot of shearing action going on as they move...so the oil has to be of a certain type.

80W-90, and 75W-90 work just fine...as long as they're GL5 hypoid lubes.

Synthetic or regular is a personal choice.

Dont buy it from the dealer. The dealer around here just uses carquest fluid. Cheap ass fluid that they buy for $2 and sell for $10. You can buy the same stuff down the street for $2.

 

Its not hypoy, its hypoid. Yes that is the proper fluid to use. All the diff fluid that we use needs to be hypoid.

 

unfortunately honda does not make a rear diff fluid for the s2000. many dealers often use the honda VTM-4 fluid which is designed for the pilot and CR-V. the use of VTM-4 fluid for long term is known to cause differential failure down the road.

i would flush your diff and fill with a correct diff fluid

-a

 

ok thx guys. I'm just going to use it since I already bought it for $6. I already ordered LE1605 for future diff oil changes.

 

It will work fine, normal gear oil not synthetic.

 

is synthetic that much better? is it just better protection? performance?

mobil 1 75w-90 syn is what i hear

 

I would recommend Redline 75W-90 for rear diff