Stupid question I know, but the book specs 90 weight, but all that I generally see is multigrade. I use the 80-90 as it does not get too cold here, and as I understand it, the broader the range on a multigrade oil, the less durable it is, but I probably don't have that good a grasp of the situation.

Does it matter if you use 80-90 or 75-90 hypoid oil?

I don't think it will make a significant difference. When these cars were built multi-viscosity oils were not yet widespread and Porsche and VW specified single grade oils for the engine (30 wt) and tranny (90 wt). Now manufacturers all spec multi-visosity oils for basically the same applications.

The designation of a 80-90 multi-grade oil indicates that it will have the viscosity properties of an 80 weight oil when cold and the viscosity of a 90 weigt oil when hot. I've used multi-grade tranny and engine oil for years without any apparent failure.

OMG! My tranny just siezed up! Just kidding (I hope)!

Get the Swepco 210 90wt and your tranny will thank you.

Just as long as the oil you use meets GL5 specs, you'll be fine. NOT any other kind, no mixes, no one size fits all, GL5 ONLY! The Cap'n

Heard a lot of props for the Swepco, and have no doubt it is an excellent product.

I use the same Valvoline lubricants that got me 350,000 trouble free miles out of my bug's motor and transaxle(Yes it is running still, and it is still trouble free). Call me a Krusty old Kodger, but I don't see a reason to change from something that has provided me excellent results for about 30 years.

Why exactly is Swepco worth twice what the Valvoline costs?