Red Line 50205 SAE 75W80 API GL-4 Manual Transmission and Transaxle Lubricant (MTL) Car Gear Oil - 1 Gallon

This Red Line manual transmission fluid makes your transmission shift smooth as butter.

Really like this 75w80 GL-4 MTF from Redline. Works better in my Honda/Acura than Torco MTF. The Torco fluid is really good stuff (I think better) but I picked up a vibration out of 2nd gear, perhaps it was just too slick for the differential or other MT components. This Redline 75w80 GL-4 MTF is of a lower viscosity than the Torco and seems pretty comparable (only in viscosity) to the Honda HG MTF which sounded horrible in my car and wasn't very smooth. My service manual originally recommended 10w-30 motor oil for the MT but then Honda came out with the MTF HG stuff which I tried and immediately switched it out. This Redline is really good stuff and is in the high quality category of Torco, Motul, Mobile One, Amsoil. It's really good, but generally there are certain lubricants that will work better in your car or motorcycle than others. You just have to try them out and unfortunately that can get pretty expensive, since this gallon option was basically $15.60 a quart. Do the research and limit your selections. Since the manual recommends 30k transmission oil changes, this long interval would justify the higher price per quart.

I have used this in both of my late model Mini Coopers. Shifts smoother than standard fluid and my transmissions seem happy running it!

I’ve tried Pennzoil Synchromesh and Amsoil Synchromesh but Redline MTL is the gold standard. 6 quarts through the tower (without coolers) works great for brass or lined synchros.

2020 Tacoma shifting smooth and did this 2 months ago and about 1000 miles. Would buy again

Always a product you can trust

As expected

(PLEASE NOTE: old oil shown in photo is the old genuine Mazda fluid! It is NOT used Redline oil.) I used it in my 2010 Mazdaspeed3 with around 75,000 original miles. I changed it myself, shops in the area didn't want to bother with it. The original trans oil had never been changed (quite simply because, Mazda claims the original factory fluid is a "lifetime" fluid, which it is obviously NOT), and came out of the car looking dark as cocacola, and thick as (real) maple syrup. Whereas this new liquid is transparent, with the slightest hint of red, and flows quite a bit easier than the old, nasty black fluid. Before I changed it, I was having serious issues getting stuck shifting into 1st and 2nd (the shifter often wouldn't want to move all the way into gear). It was so bad that I was considering getting rid of the car. But this new oil fixed it 100%. With the old oil I also had an issue with 2nd gear going in with a crunch (worn synchro probably?), this oil didn't completely eliminate that crunch but it reduced it a lot, and now it goes away completely when the car is fully warmed up. I still can't believe Mazda doesn't have a service interval for changing the transmission fluid in the speed3. This fluid absolutely needs to be changed. As for how to change it in the Mazdaspeed3: https://www.youtube.com/watch?v=yWMk_Q1pE8c Tip: If you can manage to find a funnel long enough, or extend the one you have, then you won't need to remove the airbox. I extended mine with a plastic water hose.