Red Line 50204 SAE 75W80 API GL-4 Manual Transmission and Transaxle Lubricant (MTL) Car Gear Oil – 1 Quart (2 Pack)

I have an ’07 BMW 550i with a stick shift that I picked up this past summer. No idea when or if the transmission oil was last changed. The gearbox mostly shifted fine, but there were times it was reluctant to go into gear, and crunched a weee bit on occasion, so I figured a transmission oil change was a good first step. BMW, of course, only recommends their own $50 per liter solution, but this redline MTL was recommended on a couple of sites / forums @ half the price.Oil change was stupidly easy, with the worse part being the removal and reinstall of the underbody tray. Note that the car does need to be level in order to refill the gearbox properly, so that may be easier for some than others. I am fortunate enough to have a lift, so it was <30min job. It took a full 2qts, so if you have an e60 V8 BMW manual, you may want to grab a 3rd qt just in case you have some spillage. There are plenty of online videos with instructions you can search for help.The old oil in the gearbox was definitely well used, but not so terrible that I would believe it to have been the original oil. BMW has this stupid concept of "lifetime fill" with transmission fluid for the past ~20 years. This obviously discourages proper maintenance, so it really wouldn't have been surprising to find original fluid in a 16 year old car with 110k miles. I did the differential fluid as well with the redline oil recommended for that application.I did not notice much of a change the first couple trips after the oil change, but after 50-100 miles, I could definitely tell the difference. Every shift has a more "syrupy" feel to it, and the shifts slot into place with a more positive action overall. This gearbox still doesn't like to be rushed. This MTL fluid won't turn your BMW into a Honda, but it definitely works well and costs a lot less than the "genuine" oil. Definitely a worthwhile job to perform yourself, if you are able, and a great product to improve the driving experience.