Mobilube PTX is the oil spec'd for these transmissions. It is special for these transmissions which are manufactured in Japan by Aisin.

Like others, I changed my factory fill of PTX for a fresh fill of PTX and it made no difference in the shifting. Installing a Numeric Racing shifter and cables took away the 1-2 grind that would happen when cold, but it can still be tough to get into 1st and 2nd when cold. This is just a known quirk of these transmissions. I read somewhere it is because they use steel synchros for 1st and 2nd for durability purposes - stronger than brass but also harder to shift especially when cold. You can't really fix the issue with an oil change, but an oil change is a good thing to do for the longevity of your transmission.

 

Maybe, but there have been many owners that don’t seem to have this problem. And then when the car warms up, first gear is attainable.

 

Most gear oils will meet the quality required. The difference with PTX is the viscosity which functions well with the Porsche synchros.