MT-90 for racing?

[Som]

Hey, don't mean to start a big debate about tranny fluids as there are already a ton of them around. I've read about the recommendations about using various Redline products depending on the sticker/plug type and all that.

But the general consensus appears to be -- you're safest bet is to use MTL. So, unless I get any more info, I'll probably end up going that route.

That said, most of that consensus appears to be around cars that see street driving, where cold temperature performance would be necessary.

So my question is, if I'm looking for a race car fluid for the tranny (Spec E30), wouldn't it make more sense to go with a thicker fluid? My understanding is MT90 is just thicker MTL (which is 80 weight on the hot end). Not really understanding why MTL would be a desirable alternative given the application.

Thoughts?

Som

[JinormusJ]

I use MT90 in my street vehicle

I would go with a thicker weight for raving applications. MT90 is good unless you want heavy duty stuff

[Som]

Another data point might people who used MT90 that noticed poor diff performance on the track that improved by switching to MTL.

I've read switching between MTL and ATF for various reasons, but not MTL and MT90...

Som

[jlevie]

A thicker fluid means more rotational resistance and thus a loss of performance. I use ATF in the race car and MT in the street car.

[Som]

Thanks Jim.

Just realized I said "diff performance", of course I meant transmission. :)

Any particular effects I should be aware of with using the ATF? Or things to expect for particularly hot days?

Thanks,

Som

[jlevie]

I've never hd any problems in any weather.

[Som]

So... dumb question. Redline has D4 ATF (30504) and Racing ATF (30304). Most the comparison discussions I've seen seem to refer to the D4 when using ATF for manual transmissions.

Any reason to not go with the "racing" version? Or will that be a thicker version that maybe also adds unnecessary resistance?

Som