Thanks for the question, Bryce. No, you don’t have to change out the transmission fluid. You can leave it in for the life of the fluid. It’ll be fine for the time until you decide to change the fluid.

Good question. Yes, you can use Trans Tune in your Toyota’s automatic transmission. It’s safe and effective in 1991 transmission. Just follow the directions on the can.

Good question, JD. Yes, Trans Tune is safe and effective in a 2015 Renegade 9 speed automatic transmission. Just follow the directions on the can and pour it in the transmission fluid reservoir.

Good question, Mike. Warm the vehicle up to operating temperature, and check the transmission fluid level. As long as it’s not overfilled, you can add the Trans Tune without draining any transmission fluid. There’s plenty of capacity for 16 oz. of Trans Tune.

Good question. Yes, you can add the whole thing and leave it in there until your next regularly-scheduled fluid change. It won’t hurt anything, and it will work to condition the fluid for as long as it’s in there.