2019 MX-5 25k mi; ST 5w-20 syn 10k mi

dnewton3

dnewton3

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This UOA is from last year, but I just got around to posting it ... sorry for delay.

Mostly spirited cruising; some highway, some city. Averaging around 39mpg. Spin it to redline once in a while but spends most of it's time between 2000-4000 rpm.

Bought the car used with only 3k miles on it. Here's the OCI history:
- at 5k miles; dumped the OE fluid and put in some OR's 0w-20.
- at 15k miles; dumped the OR's lube and put in ST 5w-20
- at 25k miles; dumped and put in more ST 5w-20 (UOA below is on this OCI change)


1682275673230.png
 
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The ST looks like it did a great job there. Only thing that stands out to me is the sodium @ 85ppm. Seems a bit high compared to most other UOAs I’ve seen.
 
dnewton3 said:
This UOA is from last year, but I just got around to posting it ... sorry for delay.

Mostly spirited cruising; some highway, some city. Averaging around 39mpg. Spin it to redline once in a while but spends most of it's time between 2000-4000 rpm.

Bought the car used with only 3k miles on it. Here's the OCI history:
- at 5k miles; dumped the OE fluid and put in some OR's 0w-20.
- at 15k miles; dumped the OR's lube and put in ST 5w-20
- at 25k miles; dumped and put in more ST 5w-20 (UOA below is on this OCI change)


View attachment 152269
Click to expand...
Seems like you're enjoying it by the mileage you've driven. Fun little car for sure.
 
ThatNavyGuy said:
The ST looks like it did a great job there. Only thing that stands out to me is the sodium @ 85ppm. Seems a bit high compared to most other UOAs I’ve seen.
Click to expand...
Yeah, sodium combined with potassium seems a little worrisome. Both are much higher than virgin levels, though still low enough not to scream coolant.
 
You have the maintenance reminder set to a Fixed mileage interval?

I’m wondering what it would showed on the flexible setting, going off of your driving style.
 
Artem said:
You have the maintenance reminder set to a Fixed mileage interval?

I’m wondering what it would showed on the flexible setting, going off of your driving style.
Click to expand...
it's set to 5k miles fixed. I just reset it and OCI every other reminder (10k miles).
 
dnewton3 said:
Manual, of course. Anything else would be pure heresy.
Click to expand...
Enjoy. Owned a '19 for a about 18 months through covid. It kept me sane. Good times. I highly recommend Redline products for the transmission (much improved shift feel) and rear end.
 
I did "upgrade" the manual trans fluid to the MT-90 already at 15k miles, just to get the OEM fluid and it's wear-in metals out of there.
Did the same to the rear, but used some ST syn 75w-90 I had on hand.
 
dnewton3 said:
I did "upgrade" the manual trans fluid to the MT-90 already at 15k miles, just to get the OEM fluid and it's wear-in metals out of there.
Did the same to the rear, but used some ST syn 75w-90 I had on hand.
Click to expand...


FWIW, I have 2 RX8s and one of them has, I believe, the same Mazda-built trans platform as your car, my other is an earlier Aisin built 6 speed.

I now use Redline MT-LV in both, and have almost 80K miles combined and found it to be the best for shifting. I tried MT-90 (recommended by Redline for these trans.) , Motul 300v, MTL, Ford XT-M5-QS, and decided to try the MT-LV. It is very low visc, but seems to hold up well even in the Arizona heat, on the street. I found MT-90 to be the worst of the lot in both transmissions, for synchro action.

Both trans have fairly high mileage, one is 180k, one is almost 230k (the weaker Aisin).

The Aisin had a weak 5th gear synchro, which is "fixed" now, hot or cold. I noticed a difference right away from the first drive.

Some other RX8 guys have tried it with the same results.

Anyway. try it, you'll like it!
 
I was happy to get the OEM trans fluid out; just a means of dumping the break in metals.
I, too, wasn't really impressed with the RL MT-90. It's not "bad" shifting, but it's not the improvement I had hoped for.
However, I'm not dumping it early; the MT-90 is tolerable and it was expensive so I'm going to get some value out of it before draining it.
 
Sorry to hijack. I have redline MTL in the CX-5 and am not thrilled with the shifting. This is the skyactiv 6sp manual. I've tried the Ford Ford XT-M5-QS but it wasn't in there long enough to pass judgement (had to repair a leaking CV shaft seal from the first owner). Would the MT-LV work for me? Opinions are sought.
 
I am not sure about your CX-5, but the MT-LV is GL-4, so it should work.

Both my RX-8s have aftermarket lightened flywheels, and drop rpm between shifts very quickly. With the other fluids, the synchro was slow to match shaft speed, so especially the 1-2 shift was always difficult to be smooth. With the MT-LV, that shift was now easy, since the action was that much quicker. So, the synchro is working better.

As far as durability, so far so good. The Aisin is known as a very weak box, weaker I'm sure than either of yours, and the RX8 is heavier, and more powerful than the MX-5, and has a 9K rpm redline. All factors in box longevity. I am about to change the Aisin fill at 40k miles, just because, not that there is any problem. Again I would highly recommend. Not cheap, but worth it.
 
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KEVINK0000 said:
I am not sure about your CX-5, but the MT-LV is GL-4, so it should work.

Both my RX-8s have aftermarket lightened flywheels, and drop rpm between shifts very quickly. With the other fluids, the synchro was slow to match shaft speed, so especially the 1-2 shift was always difficult to be smooth. With the MT-LV, that shift was now easy, since the action was that much quicker. So, the synchro is working better.
Click to expand...
The stock MX-5 flywheel (especially the 2019+ with the revised high-reving engine) is also very light; hard to rev match.
I'm now intrigued about the MT-LV ....

Darn you Kevin - I was willing to tolerate the MT-90 and now you've got me thinking about the LV!
 
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