I added both the transmission and engine Tribotex simultaneously.
My HHR has just over 208k miles, with the GM 4T45E automatic transaxle and the 2.4L Ecotec 4cylinder engine.
Neither engine nor transmission was particularly causing me concern. Engine would start right up, decent power, smooth operation. The transmission functioned well, though inconsistent in when it would shift smoothly. Shifts were quick, though a greater tendency to jerk into the next gear. Torque converter lock up could be harsh, especially with more throttle.
I felt it an ideal testbed for the new Tribotex transmission formula. Having already used the engine treatment, on another vehicle.... I knew the results were going to be astounding.
I made myself wait until the 500mile break in period was done, before writing this review.
I'm going to gush about this marvelous invention. I was ready to give a five star review at 200miles. It completely smashed any thought of what my car was going to become, after installing the treatments.
Transmission: huge improvement! Like 90% new. I think if I changed out the solenoids... I'd basically have a new transmission. The shifting is almost entirely smooth and imperceptible, save for the change in engine torque. The torque converter lock up, at any engine speed or throttle input, has became entirely smooth, with very occasional glitches. Even engaging the transmission (going from park to reverse, then reverse to Drive) has absolutely no feel to it. Downshifting is so quick, it's almost like driving a CVT.
Engine: worlds of improvement! in terms of start up feel, vibration, power delivery (this engine has never felt particularly powerful, merely adequate. After the treatment, it pulled like I had just added turbo charger... Even with the car loaded with my camping gear) even in day to day driving, the engine is much less strained. I can keep the rpm's around 2k and get up to speed effortlessly. I also noted that it would cool off much quicker, say after coming the top of a hill.
Anyone who is dreading a massive repair bill, check out Tribotex first! I estimate that doing... nothing, save for fluid changes, my transmission and engine have another 150k of life, At least.
Thank you for this amazing product!