Macster

For the 2003 (my Turbo's MY):

Dock

I have it.

I believe it is available on-line.

peritus

TA! This is helpful.

Dock

At least for the '02 996 Turbo, Porsche recommends changing the manual transmission fluid at 90,000 miles/144,000 km. They also recommend changing the oil every 15,000 miles/48,000 km. If the car is driven <9,000 mles/15,000 km yearly, they recommend changing the oil after 2 years.

993GT

Fluids are cheap and they WORK to prevent failures...I fix failures and is 'good' for me, but people can do whatever they like...anyone who thinks the OEM's suggested fluid maintenance schedules are meant to be best for their car is fooling themselves, OEM's 'sell' the extended intervals to improve post warranty service sales and 'improve' early life car experience (low service requirements).
In addition to providing lubrication, most fluid additive packages also contain conditioners to maintain seal life...

911mhawk

$60/gal Delvac for trans oil change is cheap insurance vs going the recommended interval. It is noticeably thinner after just a few thousand miles of rigorous use. I think 15k for non-track used cars would be smart.

Brake fluid is cheap too, $40 would get you fresh RBF every year, at least do enough each spring to get fresh into the calipers. If you use max braking capabilities regularly in succession, heat transfers into the fluid degrades it enough you can tell the difference with fresh fluid.

I recently changed my X5 with "lifetime" transmission fluid and even did the filter, just common sense stuff really, unless you want a short lifetime. The fluid at 130k looked like it should have been changed about 3 lifetimes ago...

Anything with Pentosin I'd leave until it pukes out somewhere on it's own; hate the stuff. It seems to come out somewhere every 4 years or so anyway and is toxic enough that it should last forever if not?

fung0001

Too good to have it👍

Dock

Do you have data supporting the shorter transmission lifetime if the oil is not changed more often than recommended?

911mhawk

ZF, the manufacturer of the X5 transmission has a technical recommendation for 100k. BMW calls it lifetime.
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powdrhound

Porsche changes engine / gear oil in their Cup cars every race / event while cars and coffee warriors get 15k/90k interval recommendations. Change your oil on a schedule you are comfortable with depending on your type of use. One size does not fit all.

I change engine and gear oil every 6-8 track days which amounts to 500-600 track miles. Based on visual and black stone oil analyses, this is a good interval for my use. 9 bottles of M1 5w50, 1 gallon of Delvac, and one filter cost a total of $100. Takes 1 hour to change so it's a no brainer.

Guard transmission, maker of gears and LSDs for these gearboxes has the following gear oil change interval based on the countless gearboxes they have come across. 15k street use interval with 1 track day equivalent to 1.5-2k of street use. Just a rough rule of thumb as a track day in the green run group will take a different toll on the gearbox than a race day will. 15k seems a bit conservative for strictly street use and I would personally feel ok with 30k intervals but that's me. Do what gives you the warm and fuzzy. If 90k is that number, have at it.

Dock

That's not data showing there is shorter transmission lifetime if the oil is not changed more often than recommended.

911mhawk

I know that, do you think I'm part fish?

911mhawk

This^ and to add, when I had my box redone Copans said the factory recommendation of 90k was ludicrous unless you're a total wuss (not a direct quote).

Dock

I asked a question, and you offered a response to that queston that fell short in terms of my data challenge. I point that lack of data out to you, and you reply "I know that". So this still leaves us without any data.

I personally think that there IS no data, but I could be wrong and therefore wanted to make sure by asking you to provde the data.

"02996ttx50

i dont know about the potential longevity for synthetic motor oil(s) but i change mine at 5k miles religiously.

coolant, i only change if i don't keep a full fresh 50/50 mix of g13 and i feel its become overly diluted, or if a rad change occurs ( once ).

even more importantly, i change my trans fluid w delvac every 15k miles and perhaps even less ( mileage ) as I've already changed it since opening/refreshing my gearbox less than 10k miles ago. the fresh trans fluid change is always instantly noticeable marked by the ability to shift effortlessly with a cold engine off, which is usually when shifts feel "notchy". flush your trans oil, and your gearbox will thank you.

the porsche factory intervals for fluid changes are optimistic at best, and are far from optimal. but they only make money when we buy new porsches, so i can see them extending their recommendations to the outside range of the limitations of the fluids integrity. but either way, 90k miles on trans fluid is absurd.