Geoff, I run Redline MT90 synthetic gear oil year-round in my manual tranny on
my 88 GL. Have now for nearly two years. It gets very hot here in the deep
south and remains so for  5 months a year.

MT90 can be added to a transmission with residual( as in after draining)  dino
oil and it does no harm.

John Rodgers
88 GL Driver

geofflaw wrote:

> Hi volkspeople
> decided I'd change the oil in my recently acquired '82 which has  4 speed
> manual trans.
> got down to Marlow's and then I was faced with the choice of mineral 80/90
> or synthetic gear oil. What to do? I didn't buy either, thinking "the guys
> on the list will know what's best."
> This will be a once only change for me and this car.
> BTW I live in a meditteranean climate. We never see ice and snow, but in
> summer we see plenty of really, really hot days. (over 40 celsius.)
>
> Geoff Law
> Perth, WA
> '82 Trakka