Quote:
Originally Posted by paulofto
I went to the Porsche dealer in town here and the parts guy quoted me $48.00 a quart (964ml) for OEM Porsche MT Fluid. I almost swallowed my gum I gasped so hard. 
The service manager happened to be there and he tells me the stuff is made by Royal Dutch Shell in Europe but it is the same stuff, 75W90 GL-5, available from Quaker State in North America, a subsidiary of Shell. He further tells me that although Porsche specified GL-4 when the Boxster first came out years ago, the GL-5 spec today meets all of Porsche's requirements. Something about the sulfur molecules are now compatible with sychros and high pressure differential gears. A little too technical for me but he said they issued a TSB a few years back now specing the new GL-5 formulations.
Anyway, long story short, I thanked the service guy at Porsche but told the parts guy I can't justify $150 on MT Fluid when Quaker State 75W90 GL-5 sells for about $18.00 a quart at most auto supply places and Crappy Tire sometimes has it for less.
So I picked up 3 quarts of Quaker State and I will be changing the fluid on Saturday. I have 74,000 Km (46,000 M) I am doing all fluids over the next few weeks but starting with engine oil and MT.
I'll let you know if I feel any difference in shifting. Currently it is a little 'notchy' when cold but is fine when warm.  |
Hate to burst your bubble, but the information you were given is somewhat correct, and somewhat incorrect.
The original Porsche gear oil for the five speeds was developed for Porsche by an obscure Royal Dutch Shell division known Burmah, and was designated TAF21. This full synthetic product was developed specifically for Porsche for the Boxster five speeds only, and should not be use in the six speed boxes due to incompatibility with certain alloy components, which would result in premature wear. Porsche actually published a technical bulleting to that effect. Burmah TAF21 never had any type of GL rating as it simply did not fall into any of the GL categories as defined by the API, which is also why other major oil companies never made an equivalent product. The TAF21 product is made exclusively for Porsche in 20 liter drums. The Quaker State GL-5 product is not an equivalent lubricant, which is also why you are experiencing cold shifting issues, a condition where the TAF21 excels over other lubricants in the Boxster.