Changed MTF to Amsoil Synchromesh, I am Happy!

[amirza786]

Mild winter this year but when it does get cold it doesn't shift as well on AmsOil as it did with Honda MTF until warmed up. A couple of second gear lockouts and crunches, so I just shift WAY slow until the transmission has some heat in it.

That's unfortunately the nature of MT's in extremely cold climates. Thankfully, cold here is when it hits 50 degrees, and really, really cold is when it dips down to 45 degrees F

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[zhendexing]

I know that this an old post, but it's not that expensive. $16 x 2 quarts, and you change it out every 50K to 150K. Genuine Honda MT fluid is almost $13 per quart, so you are actually spending more money changing it out at 20K, when with Amsoil you can wait to do it at 50K for severe driving and 100K for normal driving. Anyway, thought I would add my two cents

Impossible to shift to first gear in winter unless car is completely stop. Even after 20 mins normal driving it still does that. Takes forever to completely warm up. I would recommend sticking with Honda mtf if you live anywhere cold and your car is parked outside or in detached garage. I went from Honda mtf to motul to amsoil to royal purple and back to Honda mtf. My 2cents.

 

[amirza786]

Impossible to shift to first gear in winter unless car is completely stop. Even after 20 mins normal driving it still does that. Takes forever to completely warm up. I would recommend sticking with Honda mtf if you live anywhere cold and your car is parked outside or in detached garage. I went from Honda mtf to motul to amsoil to royal purple and back to Honda mtf. My 2cents.

I guess then the answer would be, if you live in an area with a cold winter climate, stick to OEM, although I would think a synthetic would perform better in the cold weather

 

[zhendexing]

I guess then the answer would be, if you live in an area with a cold winter climate, stick to OEM, although I would think a synthetic would perform better in the cold weather

Because Honda mtf has a much lower viscosity, and a pretty high viscosity index of 200+. Royal purple has a comparable low viscosity but the viscosity index is lower so the thickness of the fluid change quite a bit when temperature changes.

 

[amirza786]

Because Honda mtf has a much lower viscosity, and a pretty high viscosity index of 200+. Royal purple has a comparable low viscosity but the viscosity index is lower so the thickness of the fluid change quite a bit when temperature changes.

According to their datasheet, it's supposed to handle temps down to -40C

 

[zhendexing]

According to their datasheet, it's supposed to handle temps down to -40C

It flows at -40C at a slower rate compared with other brands.

Pic1 is royal purple, it has much lower viscosity (9,178cp) at -40c, picture 2 is redline 75/80, (at 120 poise, 12,000 cp) also way lower than amsoil.

 

[charleswrivers]

I thought it performed well in the -15F winters I endured in upstate NY some years back on an RSX I had at the time. It was the 2nd or 3rd MTF I tried after draining the Honda MTF and was actually chosen because it had good performance in both cold and hot while beating the Honda MTF at that time. By the time I got to the AMSoil, it had been a few months since I’d used the Honda MTF so I didn’t get a back to back comparo... but the AMSoil didn’t really have issues in the cold compared to the other couple ones I’d tried (can’t remember which ones anymore, unfortunately. One was one you could get in a brick and mortar store clubrsx forums talked up. I think there was another I sent out for. I didn’t try redline. Redline is actually what performs better in my Z and is in it now. They did so bad in the cold though, it’s what made me drain them and try something else during the first winter I had the car).

My winters here in GA rarely dip below the 30s... and never under the 10s... so, yeah... enjoy those you’ll-die-if-you-stay-outside temperatures. And I thought NY was cold...

 

[zhendexing]

I thought it performed well in the -15F winters I endured in upstate NY some years back on an RSX I had at the time.

I think it’s because older trannies came with thicker mtf.

Old Honda mtf spec:
Honda MTF-7289
Viscosity at -40C, cP 60,000
Viscosity at 40C, cSt 53.2
Viscosity at 100C, cSt 10.50
Viscosity Index 190

the spec is very close to amsoil probably the reason amsoil mtf performed better in older cars.


the newer Honda mtf spec:
@ 40C = 30.70 cSt; @ 100C = 7.265 cSt

 

[Shonuff]

This is why I love forums all these posts are super great and helpful. Due to the colder winters here it looks like I'll stick with the Honda mtf until I win the lottery and move to somewhere where snow and parkas are just things people see on tv!

 

[mis3]

This is why I love forums all these posts are super great and helpful. Due to the colder winters here it looks like I'll stick with the Honda mtf until I win the lottery and move to somewhere where snow and parkas are just things people see on tv!

I live in Toronto as well.
I did change my MTF to Amsoil last summer. While the Amsoil may have improved the shifting somewhat, I did not experience day-and-night difference. Good thing Is I do not feel any deterioration in shifting in the winter months. i
I do not regret the change because in theory, synthetic oil would protect the transmission better than conventional oil.

 

[charleswrivers]

I think it’s because older trannies came with thicker mtf.

Old Honda mtf spec:
Honda MTF-7289
Viscosity at -40C, cP 60,000
Viscosity at 40C, cSt 53.2
Viscosity at 100C, cSt 10.50
Viscosity Index 190

the spec is very close to amsoil probably the reason amsoil mtf performed better in older cars.


the newer Honda mtf spec:
@ 40C = 30.70 cSt; @ 100C = 7.265 cSt

Very likely. Might also stand to reason why the cars 10 years back said you could use the same viscosity motor oil as what the engine took as a temporary substitute. 5w-30 fell to 0w-20 in the intervening years... along with the manuals allowance. I’m pretty sure the AMSoil I bought this past year was the same as what I used back in ‘09-10 timeframe in the RSX.

 

[amirza786]

Very likely. Might also stand to reason why the cars 10 years back said you could use the same viscosity motor oil as what the engine took as a temporary substitute. 5w-30 fell to 0w-20 in the intervening years... along with the manuals allowance. I’m pretty sure the AMSoil I bought this past year was the same as what I used back in ‘09-10 timeframe in the RSX.

It's funny, my owners manual for my 2018 stated that you could use 5W-30 motor oil as a temporary substitute for Honda MTF, but in the revised owners manual (February 2019) they changed it to 0W-20 or 5W-20

EDIT

In places with moderate temps year round, I would still use Amsoil Synchromesh over OEM, as from my experience, the transmission performance was much better. To correct the shifting issues such as notchiness and issues shifting from first to second, that can be corrected by the Acuity Performance short shifter kit, the same one installed on @TypeSiR 's CTR

 

[saiko21]

A question for everyone who used amsoil syncromesh oil. It says not to used with LSD on the package?
SI has LSD inside transmission

 

[amirza786]

A question for everyone who used amsoil syncromesh oil. It says not to used with LSD on the package?
SI has LSD inside transmission

It's fine to use in this transmission, the LSD is housed in the transmission. What they are referring to is a rear differential that has an LSD. In that case you would use gear oil which is 75W 90. They are not going to sell you a product that will damage your transmission or it's components. Source: Amsoil Support

 

[blitz]

The Amsoil Synchromesh or the Royal Purple Synchromax are really good MTFs for the Civic gearboxes.

Brookfield Viscosity Test (ASTM D2983) @ -40C / -40F: Lower number means less resistance to flow
1. Amsoil Synchromesh: 32,075 cP
2. Royal Purple Synchromax: 9,178 cP

What is ASTM D2983 setup:

Approximate cP values of common items at room temperature (70F):

The RP Synchromax does exhibit less resistance against the spindle than the Amsoil Synchromesh at -40F/-40C. However, I think these temperatures are extreme, and the fluid temperature does increase as the vehicle is driven. Nonetheless, gear operation in the box, generally speaking based upon this data, points to smoother operation initially from the Synchromax when the oil is “cold.” I changed my Amsoil to the Synchromax recently, however, I am in the northeast. Hopefully this illustration helps.