i have swepco, i believe 201, and it shifts badly when cold but very smoothly when warm, over factory which was just somewhat stiff all the time.

 

Swepco 210 is VERY thick... you will be losing horsepower if you use that fluid because of the internal drag... if you are doing endurance racing then its ok because the heat will make it thinner...

why does your shop not recommend 201 for the 996?

 

Swepco is an interesting choice.... curious why you would use a mix of this and ATF when there are good synthetic alternatives available...... Who is your wrench??

Cheers

 

I bought Swepco tranny fluid for my '99 996 last year and purchased what they recommended for my Porsche. Although it did not eliminate my cold weather shifting difficulty, it did make it a bit better.