OK to mix Redline MT90 and Royal Purple Max Gear 75W90 in manual trans?
01-21-2008, 02:55 AM
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OK to mix Redline MT90 and Royal Purple Max Gear 75W90 in manual trans?
Some people have reported that Redline MT90 in the manual transmission can be notchy in the cold until warmed up (although currently I have it and it's crisp when cold). Others have reported that Royal Purple Max Gear 75W90 can sometimes lead to grinding (because it's a GL5) and may possibly cause premature wear.
I currently have RP Max Gear in my differential and I'm going to change it with more of the same, which means I'm going to need two 1-quart bottles. Because the differential will take about 1.5 quarts, I will have 1/2 quart left.
With the 1/2 quart of RP Max Gear that's left, what if I put it into the transmission and then fill up the remaining with Redline? Are the two products mixible? My thinking is to reduce the chances of premature wear/grinding (from RP Max Gear) as well as the chances of notchiness (from the Redline).
I have read quite a few threads where people do the 1/3 Redline MTL to MT90 mix. However, I have not found a single thread or post reporting that someone mixed the two brands like I'm suggesting.
What do you guys think about my idea?
I currently have RP Max Gear in my differential and I'm going to change it with more of the same, which means I'm going to need two 1-quart bottles. Because the differential will take about 1.5 quarts, I will have 1/2 quart left.
With the 1/2 quart of RP Max Gear that's left, what if I put it into the transmission and then fill up the remaining with Redline? Are the two products mixible? My thinking is to reduce the chances of premature wear/grinding (from RP Max Gear) as well as the chances of notchiness (from the Redline).
I have read quite a few threads where people do the 1/3 Redline MTL to MT90 mix. However, I have not found a single thread or post reporting that someone mixed the two brands like I'm suggesting.
What do you guys think about my idea?
01-21-2008, 04:22 AM
#2
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Considering the tranny takes 1.8 quarts, you'll still need 1.3 quarts of Redline and so will buy 2 quarts regardless. It's probably better to stick with pure MT90 if it works for you. My transmission doesn't like MT90 and prefers Royal Purple, but I have a feeling that might be down to a tolerance issue.
I don't think Royal Purple is harmful to synchros. While the MaxGear is a combo GL-4/5, it seems that it's been formulated to not eat synchros like a pure GL-5.
I don't think Royal Purple is harmful to synchros. While the MaxGear is a combo GL-4/5, it seems that it's been formulated to not eat synchros like a pure GL-5.
01-21-2008, 07:20 AM
#3
Purveyor of fine bass
I had RP MaxGear and just switched to Redline MT-90, and the Redline MT-90 is less notchy and grind less when cold.
I drove a winter when cold (temps below freezing) with my stock fluid, and I had cold gear grind when doing 1-2 and 2-3 for the first couple of minutes (first 5-6 shifts or so). If I paused slightly in neutral between shifts, there'd be no grind.
When I switched to RP MaxGear next winter, I noticed that the movement of the shifter was a lot easier (the fluid didn't feel as thick when it was cold), and I felt less resistance and had smoother engagement. Yet I still had the cold grind similar to stock, maybe a bit better (it went away sooner).
When I switched to Redline MT-90 this winter, I noticed that the stick movement is just as smooth as RP, if not smoother, and the fluid also feels "thin" really quick (almost right away), but the cold grind is significantly less. It's still there (not eliminated), but it goes away in 30 seconds or so, in the span of 2-3 shifts. Personally, I wish I went with Redline MT-90 right away. I also noticed that shifting is even smoother when warmed up.
So I recommend you go 100% MT-90. But that's just my personal experience.
I drove a winter when cold (temps below freezing) with my stock fluid, and I had cold gear grind when doing 1-2 and 2-3 for the first couple of minutes (first 5-6 shifts or so). If I paused slightly in neutral between shifts, there'd be no grind.
When I switched to RP MaxGear next winter, I noticed that the movement of the shifter was a lot easier (the fluid didn't feel as thick when it was cold), and I felt less resistance and had smoother engagement. Yet I still had the cold grind similar to stock, maybe a bit better (it went away sooner).
When I switched to Redline MT-90 this winter, I noticed that the stick movement is just as smooth as RP, if not smoother, and the fluid also feels "thin" really quick (almost right away), but the cold grind is significantly less. It's still there (not eliminated), but it goes away in 30 seconds or so, in the span of 2-3 shifts. Personally, I wish I went with Redline MT-90 right away. I also noticed that shifting is even smoother when warmed up.
So I recommend you go 100% MT-90. But that's just my personal experience.
01-21-2008, 11:17 AM
#4
INDY RX8 CLUB - Officer
I had the M/T 90 in and tried the R/P MaxGear.... M/T 90 wins out easily. The RP is very stiff and notchy in the cold and takes longer to smooth out.. I will be changing back in the spring.
01-21-2008, 01:54 PM
#7
Here in MI the RP caused shifting issues for me when the temps dropped below 70 or so. The same with the RedLine. Both shift nice when warmed-up but the Mobil1 seems to be fine in most temps, hot or cold. As cold as it is right now, we'd be better off with molasses in the trans/diff.
Im ok. It grinds a bit if I shift too fast tho. but after maybe 1 minute, it shifts just fine.
01-21-2008, 05:35 PM
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Thanks for all the replies.
I remember a couple of guys in some old threads reported that their Redline actually shifted better in the cold or immediately after starting the car before it warmed up. I also feel my Redline in the gear box shifts really well when the car is cold. Obviously, this is the reverse of most people's reporting Redline being notchy when cold and that Royal Purple isn't. Now some of you guys here are saying that the Redline is less notchy in the cold than Royal Purple.
I wonder if it's really a difference in tolerance issue across different people's transmissions or if it's differences in precise mixing due to quality control issues at Royal Purple and Redline.
I remember a couple of guys in some old threads reported that their Redline actually shifted better in the cold or immediately after starting the car before it warmed up. I also feel my Redline in the gear box shifts really well when the car is cold. Obviously, this is the reverse of most people's reporting Redline being notchy when cold and that Royal Purple isn't. Now some of you guys here are saying that the Redline is less notchy in the cold than Royal Purple.
I wonder if it's really a difference in tolerance issue across different people's transmissions or if it's differences in precise mixing due to quality control issues at Royal Purple and Redline.
01-21-2008, 05:38 PM
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I want to ask again is there any reason you can think of against mixing the Redline and Royal Purple in the trans? Is it like engine oil, where it's ok to add different kinds of engine oil together?
If there is no reason that they can not work together, then I think I'm going to try the experiment.
If there is no reason that they can not work together, then I think I'm going to try the experiment.
01-21-2008, 05:55 PM
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By the way, what's with the transmission oil capacity? In the manual for checking the level it says to see if the level is near the brim. However, even putting 2 quarts into the transmission doesn't fill it to the brim.
01-21-2008, 07:06 PM
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This was my experience as well, so I just went to 2 quarts and stopped there. Could it depend on if your car is perfectly level? People have mentioned this in threads 3 years ago. If the rear is a little higher than the front, I can see how the capacity might go up a little.
01-21-2008, 10:52 PM
#17
Not to brag but the reason I tried the Mobil1 in the first place was simply that I get it, and all my engine oils, for free from a friend who builds and dynos Indy, Champ, and NASCAR engines. I am running 0W30 right now in my engine and I am glad I am. As cold as it is here in MI, my car starts like it's already warmed up.
01-21-2008, 10:57 PM
#18
Not to brag but the reason I tried the Mobil1 in the first place was simply that I get it, and all my engine oils, for free from a friend who builds and dynos Indy, Champ, and NASCAR engines. I am running 0W30 right now in my engine and I am glad I am. As cold as it is here in MI, my car starts like it's already warmed up.
beers
01-21-2008, 11:32 PM
#20
I second the motion.
Many track days. She works fine for me!
01-21-2008, 11:47 PM
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I get Redline for $4 a quart, which is why I decided to give it a second chance. At that price I'll probably still keep it in the diff, but my tranny needs something different.
01-23-2008, 09:39 PM
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Second, the BG website has a bunch of stuff for automatic transmissions, oils and flushing machines. But nothing for manual transmissions and no Synchroshift. Even stranger.
Sounds like another ghost product. I'm staying with Redline and Royal Purple.
Thanks for wasting my time.