[divezic]

I just filled my transmission with Mobil 1 and there is a noticeable difference. With regular trans fluid, I needed to be at almost a complete stop to slide it into first. Also, downshifting to second was tough. Now it's very smooth.

Adrian Jaye has a good point; you can't go wrong with the factory specs. The problem I see with this thinking is that the factory manual was written in 1983 (for an 84 model) and Haynes is a reflection of the factory specs. There was no Mobil 1 in 1983. There has been a huge jump in lubricant technology in the past 18 years. Porsche periodically updates their recommendations for lubricants and now recommends 0W40 Mobil 1 for winter use. That was not a recommended oil in 1983 because is was not available. I don't know if Mobil 1 is a recommended trans fluid, but I just can't see anything wrong with using it if it improves the transmission's performance. I have read, though that some people have a problem with it because it's too "slippery" and doesn't allow the synchros to engage properly. This is not the case on my 944.

Just my opinions. Hope they help.