...and now we have 31.

Those who don't learn from history...

 

Amsoil 5w30 trans fluid improved shiting over oem

 

^x2 I have the same fluid in my transmission. It improved shifting over the new honda mtf. Not that much of an improvement though.

 

A few things to consider:

GMSMFM was designed for the NV1500 transmission in 4 cylinder (low revving 4 cylinder) S-10 pickup trucks, and the smallest pickups Dodge produced. I believe it was produced by Penzoil for GM.
The fluid may improve shifting in some testy S2000 transmissions (mostly AP1 transmissions), but does not stand up to the abuse the S2000 puts out. The fluid was not intended for high RPM use - and the input shaft of the S2000 turns at the same RPM as your engine. I used the fluid for a few months and found that it initially improved shifting, but quickly broke down.

Honda MTF in its latest iteration is much better - and while it's a one size fits all solution to several manual gearboxes in the Honda line, the other cars that use the fluid are better matched to the rev characteristics of the S2000 (Civic Si for instance). Nevertheless, the S2000 puts greater stress on the fluid than what a Civic or manual Accord can produce - especially in a rear wheel drive configuration.

Amsoil MTF is the best fluid I've used to date. It is a full synthetic fluid and was specifically designed to exceed the specific Honda MTF requirements, it's specified as a direct replacement for Honda MTF, and coincidentally it's a direct replacement fluid for GMSMFM.

I turned Amsoil tech services on to the idea in 2004, informing them there was a number of Honda owners looking for a substitute for Honda MTF in their S2000s and other high performance manual transmission applications. I told them there were a number of people shelling out $9-$12 a quart for GMSMFM to help solve shifting issues. They released their MTF that specifically addressed those two specs in 2005.

Amsoil makes the best synthetic oils available, but unfortunately does not have an effective marketing program. Sometimes you have to smash a good idea off their head before they go for it. Another recent lobbying success was to get them to produce a VW/Audi TDI 507 certified oil. I'm still working to get them to produce a VW/Audi DSG transmission fluid. My wife and I own two 2010 TDI Jetta "Sportwagons". A new baby forced me to sell my other toy (APR Stage 2+ A3) and get a true family car. My wife liked it so much she traded in her CRV for one. My S2000 was once my daily driver - it only sees weekend duty. At least I didn't have to sell it!

 

Honda MTF is the way to go. The transmission was designed to use their 30 weight or 10w30 mtf which was specially designed for it. NOT 75 to 90 weight. I would think this would reduce transmission life in the long run. I wonder how many ap1 tail shaft bearings have gone bad using other than oem and thicker oils V.S. the honda mtf? just my o2 cents you guys wouldn't run a 90 weight in your engine. and im sure their are some varienty of good tranny fluid that are actually in the right weight.

 

I've tried them all and IMHO, there is no better than Amsoil. GM is great when BRAND new, but give it 1000 miles, and it starts to break down IMHO. Honda is ok, but Amsoil doesn't have ANY change in feel in between my changes, which I do every 7500 miles.

 

Curious as to what the part# for the Ams Oil MTF is?

 

my tranny shifts fawlessly on Honda MTF2 so I'm hesitant to try anything else. It had Redline MTL in it when I bought the car and I found that it didn't work very well, changing to Honda MTF2 cured all the issues. I change the fluid once a year, it's cheap maintenance IMO.

 

Amsoil MTF is the best fluid I've used to date. It is a full synthetic fluid and was specifically designed to exceed the specific Honda MTF requirements, it's specified as a direct replacement for Honda MTF, and coincidentally it's a direct replacement fluid for GMSMFM.

I used this fluid for a year in my car couldn't stand how hard it shifted when it was cold but when it was warmed up it was excellent. Funny how some fluids work very well for some and not for others in our quirky little gearbox.

I have thought of using Torco MTF 8.35@100 CST where the honda fluid is either 7.5 or 7.7 can't remember Amsoil is 9.6 @100 CST.

 

This is the biggest conundrum out there with respect to our trannies and fluid ( it pretty much applies to all trannies though). You can't go by reports by other members because every transmission is slightly different in terms of what fluid works best. So you see some members that love the operation of their trannies with Amsoil, Redline, GM , and then others post up that they work terrible in their trannies.

One fluid can work well in one tranny but can be horrible in the next tranny despite both trannies being of the same design. It all comes down to viscosity, transmission wear, and to some extent friction modification. A given used tranny will work best with a fluid of "X" viscosity and "X" friction modification. You see this often when a fluid shears down in viscosity and the tranny starts to shift poorly. Our trannies shear fluid down, but they all do that over time due to the meshing action of the gears. The other factor is the environment where the fluid is used, based mainly on ambient temps. Up here in Canada I've found that Redline MTL works poorly at cold times of the year, but works really nice in hot summer months for example.

If you find a fluid that works well in your tranny stick with it because it is likely the formulation that your tranny prefers. That's why I've resisted straying away from Honda MTF2 despite it being on the thin side, I have zero issues using it. But if my tranny started shifting poorly with MTF2 I'd look at testing other recommended fluids, which may happen as the tranny ages. Lastly it seems that all fluids degrade over time and you need to swap them out to maintain that perfect setup, you kind of have to figure out what mileage it happens at on your car and use that as a fluid change interval.