I tried there 80w90 gear lube in my 2003 gti with 6speed. I liked the lube. It is pretty bluish in color and real sticky for synchros. The Porsche guys use it in there trannies, so I gave it a shot. The only thing that was different compared to synthetic gear lube was the Swepco needed some miles driven on it to warm up in the mornings, if not, the shift from 1-2 on my transmission was almost impossible, wouldn't slide in, like there was no shift gate for 2nd gear. I had to short shift from 1-3 till the fluid slowly warmed up. If I drove slow or shifted a lot sooner, the shift from 1-2 was possible. I looked at it this way, It gave up the opportunity to slowy drive my car up to temperature instead of just starting my car and blasting down the street to wherever. When totally warmed up, I never had the 1-2 shift crunch that this transmission had when the original synthetic fluid got warm to hot.