G240 tranny fluid type

[DER E30]

So a quick impression of my drive to school today. I think I might be going crazy but I think it let me go ~2-3mph faster with the same throttle. Am I right that thinner oil will be easier to turn and thereby lower parasitic losses?

Shifts seemed a little worse than whatever I had in there before, not a terrible amount more but maybe ~85% as good as the old stuff. This less drag thing is interesting though. I'll report back when I get home, and I'll take my favorite back road on the way.

I think it got fairly warm as my drive is about 47 miles one way all at freeway speed. It did get less notchy as I got toward the end but I think the MT90 might be the way to go.

Edit:
It was ~44degrees indicated in the shop and similar outside to give an idea of the temp.

[shameson]

So a quick impression of my drive to school today. I think I might be going crazy but I think it let me go ~2-3mph faster with the same throttle. Am I right that thinner oil will be easier to turn and thereby lower parasitic losses?

Shifts seemed a little worse than whatever I had in there before, not a terrible amount more but maybe ~85% as good as the old stuff. This less drag thing is interesting though. I'll report back when I get home, and I'll take my favorite back road on the way.

I think it got fairly warm as my drive is about 47 miles one way all at freeway speed. It did get less notchy as I got toward the end but I think the MT90 might be the way to go.

Edit:
It was ~44degrees indicated in the shop and similar outside to give an idea of the temp.

Ya, I would assume the less-viscous oil would have a lower parasitic affect. I don't know how it affects throttle, but it would at least give a boost to MPG with less drag.
I like the idea of the mt-90 giving better protection to gears, especially under hard driving. The thinner maybe would be better for overall driving but mine isn't my normal dd.

[DER E30]

On the way home it was perfectly fine, It had warmed up somewhat to about 60 degrees and I did sit in traffic for a little while.

I still feel like the shifter feels more "connected" and raw compared to the old stuff. Slightly more notchy but not bad at all.

[glucklich21]

I had issues running MTL in my G240.

I drove my E30 long distances (500+ mile road trips) and found MTL would start seeping out of the transmission after a while as if it was getting too hot and too thin. Mind you this was running between 75-85 mph for hours (because Texas). My shifts would start to get real crunchy and I would have the obvious "burning rubber" smell when the fluid would eventually hit the cat. I never had this issue when I ran ATF in either of my G240s, so I'm not entirely convinced it was an isolated issue. Just my .02.

[shameson]

I had issues running MTL in my G240.

I drove my E30 long distances (500+ mile road trips) and found MTL would start seeping out of the transmission after a while as if it was getting too hot and too thin. Mind you this was running between 75-85 mph for hours (because Texas). My shifts would start to get real crunchy and I would have the obvious "burning rubber" smell when the fluid would eventually hit the cat. I never had this issue when I ran ATF in either of my G240s, so I'm not entirely convinced it was an isolated issue. Just my .02.

Is that the 75w80 weight? For me though is that I never take it for long trips. Longest has been for CCA meet which was 45 minutes away. I know from factory these ran ATF, which one do you use?

When I have a dry day this week, probably Thursday because its going to be sunny, I'm going to take a peak under and see what sticker is on the bell housing. I know some just use redline MTL regardless of sticker and some say only use ATF if you have an ATF sticker

[glucklich21]

Is that the 75w80 weight? For me though is that I never take it for long trips. Longest has been for CCA meet which was 45 minutes away. I know from factory these ran ATF, which one do you use?

When I have a dry day this week, probably Thursday because its going to be sunny, I'm going to take a peak under and see what sticker is on the bell housing. I know some just use redline MTL regardless of sticker and some say only use ATF if you have an ATF sticker

Yup, standard MTL. I did try MT-90, but more or less the same result, just took a bit longer to happen. What I did have good luck with was this ATF by Lucas.

http://lucasoil.com/products/transmission-products/2012-11-05-17-14-3

[DER E30]

So I have a few tanks of gas through it. The trans fluid has gotten better. I like it much more than I did the week I put it in. Feels perfectly normal and good. The MT90 might still be a decent idea. I can't comment on MPGs as I've been driving backroads lots lately. But it feels good.

[shameson]

So I have a few tanks of gas through it. The trans fluid has gotten better. I like it much more than I did the week I put it in. Feels perfectly normal and good. The MT90 might still be a decent idea. I can't comment on MPGs as I've been driving backroads lots lately. But it feels good.

That's good to hear. Based on what I've read I'm going to give the mt90 a try pretty soon and see how it does. Like yourself I do a lot of backroad driving and barely touch the highway

[JonnyOg]

I changed my fluid to redline mtl when i first got the car, and It never really shifted that nicely. I thought my synchros were worn, but after going back to cheap synthetic atf it feels like a new tranny and shifts 10x better.

Also after 2 years running redline mtl I had some silver paste on the drain plug :/

[Victell]

Bumping this thread.

I just installed a lightweight flywheel in my m42/g240 (RHD 8.5lb with M20 clutch and pressure plate) and there are new noises. At idle its the rocks in coffee can sound. On in-gear deceleration there's rattle noise also.

Has anyone reduced these noises with different trans oils? It sounds like heavier oil would reduce noise (makes sense), but at the cost of harder shifting when cold (also makes sense).

[bmwman91]

Running 75W-90 gear oil helps a bit. I started using Motul GEAR 300 75W-90 recently (sane stuff I use in the diff) and it made an improvement. Just make sure it is not the stuff with limited slip additives.

[Victell]

Running 75W-90 gear oil helps a bit. I started using Motul GEAR 300 75W-90 recently (sane stuff I use in the diff) and it made an improvement. Just make sure it is not the stuff with limited slip additives.

I assume those additives can mess up how the synchros work?

[bmwman91]

Correct. LS additives in gear oil are only for LS diffs haha.

[eternal24k]

My G240s love Redline ATF