Redline D4 versus MTL in the TR6060

[Camarotobeornottobe]

So, brought up for knowledge share, so don't flame.

I have done much searching on this forum, and most agree that the manual TR6060s respond very well to D4. Those who had cold fluid grinds seem particularly happy. Makes sense, since the viscosity of the D4 at cold temps is much, much thinner than the factory fill, while still maintaining the same viscosity as the factory fill at operating temperature. I have been blessed with zero grinds to this point.

Many have demonized the idea of using MTL, even when others report positive results. The logic is that it is too thick to properly lubricate the TR6060 with its tight tolerances.

On the Corvette forums, it has been recommended to do a mix, usually 3 parts D4 to 1 part MTL. No one on this forum has reported trying it. The logic there is you thicken it up a little bit for hot weather while keeping the benefits of the thinner fluid.

I was curious, as some in the Corvette forums have reported that the notoriously noise TR6060 is quieter with the MTL (or at least a mix). For you Camaro TR6060 owners, if you listened carefully, I'm sure you'd agree that the tranny is louder when the fluid is very hot (approximately 180 degrees on the gauge, for those with 2SS option). The D4 seems a little more quiet than the factory fill at all temperatures, but it too is louder when hot than when cold.

So, I wrote Redline. Here is the email string (with my info redacted, as well as the Redline employee as a courtesy). Read from the bottom up:

Joe,

Both would be safe for use in the transmission, or could be mixed.

Regards, Dave
Red Line Oil
__________________________________________________ _____________

On Aug 26, 2014, at 12:09 PM, wrote:

Do they contain the same additives necessary for protection of the 6060's internal components?

If so, could the two be mixed to obtain the best of both worlds, particularly in a warm weather only climate?

Sent from my iPhone
__________________________________________________ _____________

On Aug 26, 2014, at 3:06 PM, "David" <dave@redlineoil.com> wrote:

Joe,

Thank you for contacting Red Line Oil, in your Camaro 6 speed Tremec transmission the D4ATF would be recommended. The MTL is the next higher viscosity, would be an option for road race use though could be stiffer shifting at lower temperatures with synchros designed for an ATF.

Regards, Dave
Red Line Oil
__________________________________________________ _____________

From:
Sent: Monday, August 25, 2014 7:58 AM
To: info@redlineoil.com
Subject: Compatibility Question

Hello,

I have a 2014 Camaro SS with the 6-speed manual transmission. Your site says the transmission fluid I need is D4.

However, I have read on one or two sites that your MTL is also compatible, particularly in higher stress conditions like at the track. The trade-off would be that it is thicker and would make cold weather driving harder.

Is the MTL compatible with my car?

Joe

Bottom line, it seems perfectly reasonable for the road racers or those in really hot weather to use a mix of D4 and MTL. Is you look at the viscosity info, they are really not that far off, especially if you mix. Further, a thinner mix of the two might quiet down the trannies, if you care about such things:

D4

TYPICAL PROPERTIES
Vis @ 100°C, cSt 7.5
Vis @ 40°C, cSt 34
Viscosity Index 198
Pour Point, °C -60
Pour Point, °F -76
Brookfield Vis @ -40°C, P 52


MTL

TYPICAL PROPERTIES


API Service Class GL-4
SAE Viscosity Grade (Motor Oil) 5W30
SAE Viscosity Grade (Gear Oil) 75W80
Vis @ 100°C, cSt 10.4
Vis @ 40°C, cSt 54.1
Viscosity Index 185
Pour Point, °C -50
Pour Point, °F -58
Brookfield Viscosity @ -40°C, Poise 120

What say you?

[Stingr69]

You are splitting hairs. The D4 is marginally better on street cars in cold weather. The MTL is slightly better for race conditions. Both are good and compatible. Blend them and you get somewhere in the middle. JMO.

-Mark.

[Camarotobeornottobe]

Ummm. I think that is what I was saying

Point here, anyone considering MTL in the 6060 on this site has been demonized, and I'm not sure why. I quick search and you'll see what I mean.

Looking to see if there was an effective counter-argument to using it.

[Indydriver]

Do you really think an upgrade over the stock fluid is required for street use? My '14 2SS shifts just fine.

[376LS3]

Originally Posted by Camarotobeornottobe

Point here, anyone considering MTL in the 6060 on this site has been demonized, and I'm not sure why.

Because Tremec said NO to oil. It doesnt matter what Redline says because it is not in their power to say that it is ok to go against what a manufacturer says. If you wanna run oil, have at it. But if Tremec wanted oil inside there, they would have put it there.

[Camarotobeornottobe]

"Cause Tremec says so" is not a valid response, though I'm sure someone will jump in with "+1" or "THIS."

Anyone with any sense knows there are multiple reasons for manufacturers of engines, diffs, and transmissions to choose the viscosity fluid that they "require," and part longevity is just one number in the equation that equals "compatibility." There are also considerations like fluid cost and availability, contract talks with fluid manufacturers, previous legal rulings, fuel mileage, cold weather drive-ability, previous customer feedback, etc, etc.

No matter how much that is discussed, folks still like to get on the internet and say stuff like "if you use anything but the manufacturer specified fluid brand and viscosity, your part is doomed for failure and they won't honor the warranty."

I haven't decided on MTL (or to "have at it"), but was hoping someone would have insight into the additives, viscosity, etc that make it good or bad for our trannies.

[376LS3]

Not sure what response you're looking for. If you wanna run oil, then do it. "Because Tremec says so" is good enough for me. They designed and built the tranny. Why should I question what they say? Just dont come on here and whine when you're shit breaks because you went against the MFR suggested fluid.

[Camarotobeornottobe]

LOL, nice, constructive argument. I'll stick with the D4 because you don't want me to whine. Got it.

Are you anti-D4 because Tremec recommends Mobile 1?

[Avenging Orange]

I've never tried it, but I don't have any shifting issues. I also don't use synthetic fluids in any of my cars. AND none of them have self destructed. I used Shell Spirax...which is a common ATF used in boat transmissions.
I say go for it...at least the blend. I think you will get the best of both worlds. Good luck.

[376LS3]

Originally Posted by Camarotobeornottobe

LOL, nice, constructive argument. I'll stick with the D4 because you don't want me to whine. Got it.

Are you anti-D4 because Tremec recommends Mobile 1?

So what exactly are you looking for with this thread? You came in with facts on ATF vs MTL, and emails from Redline saying its ok to run MTL. Are you searching for approval? You dont think its possible that Tremec tried oil in the TR6060 when it was in development and found a reason why they chose to run ATF? If you are smarter than the engineers at Tremec, then whats stopping you from just doing it?

No, I am not anti-D4. I run it. Mobil 1 and Redline are BRANDS. Changing to a different brand is not the same as changing to a different fluid. Nice comparison.

[Camarotobeornottobe]

376, thank you for your input. "Tremec says so" doesn't do it for me, but I do acknowledge they MIGHT have a valid mechanical reason for forbidding slightly thicker fluid. Although, I have yet to hear actual confirmation that thickening it slightly over stock ATF is specifically forbidden by Tremec, to say nothing of the reason for such a prohibition.

It is also seems you might be putting stock in the names, "lube versus fluid." Allegedly, MTL is just a thicker D4 with all the same additives and properties -- it is not like going from red fluid to a thick brown oil. I might be wrong there.

I really wish I could find the viscosity for the factory fill Texaco ATF. For instance, if its viscosity at 40 degrees C is 50 and at 100 degrees C it is 7, that might shed some light on what is acceptable. In that case, you could say that cold MTL (even straight without mixing with D4) is only slightly thicker than the factory, and at 100 degrees it is only as thick as the factory fluid is at roughly 90 degrees.

It might also shed some light on why D4 is such an improvement over the stock fluid.

[Camarotobeornottobe]

So I exchanged emails with Tremec, and I also just called them to be absolutely sure about what I read in the email.

The rep there states there is indeed NO PROHIBITION against using a thicker fluid like MTL. He further stated that the "internet knowledge" that the tolerances are so tight on TR6060s, and thus demand the thinner ATFs, is not true.

Honestly, I didn't get the warm and fuzzies about the guy's knowledge or care factor with the question. Obviously, Tremec is not stationing its top engineers in the Customer Support Section. So, take it for what it is worth.

[376LS3]

Im with you man. The reason I say I go with what Tremec says is because this discussion has been around since the T56. There have been numerous people that have written, called, emailed Tremec about running oil in the tranny and Tremec always comes back and says stick to ATF. I would think since the TR6060 has a pump in it, you wouldnt want to go much thicker than the recommended viscosity. Thats why I dont run anything thicker than 30w through my engine. Thats what that pump was designed to move. In the end, Im sure running MTL will be fine. There are people that have run it on here and there are vendors that encourage its use. Use everyones advice as you will. Will I do it? No.

[GONIF]

Ran MTL in my 2000 Z28 ,run it in my 73 Corvette M22, but in the 2014 1LE I'm running D4 . I was going to run the MTL ,but figured why take a chance . Seams to me in high heat and road race /track use the MTL would be better . Since my car shifted great with the factory fluid ,I just changed it at 2000 miles to get the junk out and went with D4. I felt no difference shifting at all . I bet in a hot climate it would make no difference ,but below 40 degrees I could see where the MTL might be a problem.