ACDelco GM Original Equipment 10-4014 Friction Modified Synchromesh Transmission Fluid, 32 Ounce, White, 1 qt

Great fluid replacement, for most Honda 6-speed manual trans. I've used it on both my 3G TL and my FC1 Si, shifting quality increased on both but specially on the TL. Great replacement for the Honda MTF

I have owned two third generation Acura TLs with 6 speed manual transmissions at this point. I bought one at 129k miles and the other at 84k miles, with the higher mileage TL being a 2005 base and the lower mileage one being a 2008 Type-S. The 2005 had issues going into third gear pretty often (i.e. every few shifts). It would feel almost like it went in, but then would pop out as soon as you released the clutch; I was not skip shifting and have never had a similar issue in any other vehicle over hundreds of thousands of miles of driving other manual transmissions, including mostly Subarus, Isuzus, and BMWs as well as motorcycle and dirtbike transmissions. The 2008 had the same issue, but only once every few dozen shifts and it could be avoided completely by preloading 3rd gear a bit and shifting really slowly.On both vehicles, I changed the transmission fluid to OEM honda fluid and drove for about 500 miles and didn't notice any improvement. I then changed both vehicles over to this stuff and they both felt better right away and felt even better after 100-200 miles. Neither has had any issue whatsoever going into third after the fluid change to this stuff.I have about 12k miles on the 2005 base with no degradation or return of the issue, but only a few hundred miles on the 2008 Type-S. I'll report back if there is any long-term harm in using this fluid on the 3G TL platform, but for now I'm enjoying the improvement in shift quality.

Coming up on my 2nd fluid change on my 2013 Civic 5-speed manual, I did some reading on a few Honda chats and forums and some were recommending this American (!) fluid for my Japanese car! I had no major issues with the Honda MTF other than occasional stiffness when shifting into reverse. Basically, I was just curious. I love to experiment with things like this. This is thicker than the Honda fluid, so it does reduce gear whine. Shifting is a little smoother and much easier going into reverse. It's been only about a week now, but I will update if I encounter any problems. So far, so good!

Some might say that putting a transmission fluid from an American manufacturer in a Japanese car is a bad idea, until you pour some of this stuff into your manual Honda and realise Americans can do something right and the Japanese can do something wrong. I've had intermittent issues with excessive notchiness and 1st and 3rd gear lockouts on my 2018 Civic LX and seeing as apparently the transmission had never been serviced on a car with 100,000km, I went out and poured this in after some Valvoline fluid did nothing to improve the situation. Drained the trans out, poured this ACDelco fluid in, and now my Civic shifts like an actual car rather than a Logitech shifter and I haven't had any gear lockout issues. Admittedly this won't solve any grave issues like worn synchronisers, but it's worth a shot.

I’ve driven manual cars for years and never once flushed the trans fluid. After doing it here, I would confirm that it does have a noticably positive effect on shifting smoothness.Car: 06 Accord 5MT

I use this in my ‘14 Focus. It’s about half the price of the factory specified lube. My warranty expired long ago so who cares. This stuff seems to make shifts smoother.

Some 2005 Acura TL MT model owners seemed to have difficulty getting into the 3rd gear, but this fluid resolved their issues. My car is 2004 TL MT, and I never had trouble getting into the 3rd gear. I do have a bit of gear clashing when shifting into the 1st gear when above idle, so I gave this fluid a try. The colour is slightly brown as compared to slight gray of Honda/Acura OEM fluid but they both have the same odor. So far, I have not noticed any shifting improvement. In fact, sometimes I cannot get the 1st gear unless I force the shifter so using this fluid was a minus for me. I'll change it next year back to the OEM fluid (I change MTX fluid once a year or at every 10,000 miles regardless of what the owner's manual says).UPDATE: 1/09/2021 (Added one star)I've come to know that this fluid actually does help, especially in New England's winter. I've tried AMSOIL's fluid, which gave me clashing 2nd gear issue when the fluid is cold. This fluid alleviates the problem a bit, and once warmed up there's no shifting issues. I'll stick to this fluid unless something better is enginnered.