I am 2 years and 30k miles (38k miles on the clock) into the ownership of my 2015 991.1 GTS. I recently replaced all four brakes and rotors. The pedal felt a little spongey immediately after, but after about 1k miles and some bedding in it feels a lot better. However, it doesn't feel as good as when I first bought the car. The dealer performed the 40k mile service when I bought it because it was recommended due to the age of the car before I took possession, so I know the fluid was changed back then at 7300 miles. I have decided to just do the job since it is such a negligible expense. However, my question is, what fluid should I be using? I do not track the car at all. I do drive the car almost daily and am fairly spirited when I do. Canyon runs maybe once every 3 months, but for the most part it's socal highway driving anywhere from 80-90 mph. I am looking at ATE type200, the OEM fluid, Motul 600/660, and SRF. What do you guys use in your daily non track cars?

 

can't go wrong with either motul 600, ate typ200, especially if you're just dailying it. I put ATE in my cars, personally, but it's hilariously overkill for anything they see.

frankly, you can just buy whatever DOT spec fluid that's on the shelf at your local auto parts store and you'll be just fine.

 

You'll probably get some advice saying Castrol SRF or other high end option but as noted by Asellus, the basic fluid recommended (DOT 4 ATE200) will work fine. If you put it on the track then you need to up your fluid game, otherwise the fancy stuff is a waste of $$$ for street applications.

 

I used Pentosin Dot 4 from Pelican Parts when I did the flush on my 991.1 C2S. No complaints.https://www.pelicanparts.com/More_In...=6391&DID=2829

 

I recently did a brake flush using ATE 200 from fcpeuro. I daily my car and needed something which will support the occasional autocross, novice track days etc and it seemed to fit the bill. Also returning used fluids and getting refunded helps try out different types of fluids.

 

I recently did a brake flush of my 991.1 C2S and used Pentosin 4LV. Picked up a couple cans from Autozone.

 

Keep in mind the “track” fluids often have requirements to flush/change much more frequently than your street friendly DOT4 fluid, some as often as every year. That’s typically not a big deal if you’re tracking the car a lot because you’ll want to be flushing your fluid anyways, but if you’re not actually tracking the car a lot you’ll be better served with something designed for a high performance street car. ATE 200 is a great choice, the manufacturer says up to 3 years of street use without changing.

 

Ate200

End thread

 

Not to complicate things but...Porsche specifies LV fluid (low viscosity) and some people have reported getting a squeaky master cylinder when pressing the brake pedal from using non LV fluid. Most manufacturers do have a LV and a non LV formula. Personally I would opt for the LV. It is rumored that Porsche fluid is rebranded Pentosin LV. I have used it and it just fine. ATE also has a LV version called SL.6 which I have also used.

 

I use SL6 and I do experience a squeaking master cylinder of my 991 GTS the first time I press the pedal after a couple of days of standstill in my garage.
I will change to ATE DOT 5.1 . It is relatively new on the market, has even lower viscosity than the SL-6 (DOT 4), especially at low temperatures.
Do not mistake DOT 5.1. for a DOT 5 fluid. Unlike DOT 5 fluids , DOT 5.1 is compatible /may be mixed with DOT 4 fluids.
DOT 5.1 has slightly improved behaviour wrt. dry/wet boiling temps vs. SL-6, and is claimed to have longer service life.

 

That was just speculation. Plenty of us have been running non-LV high performance fluids with zero issues or noise for years.

 

I used Motul 600. No issues.

 

Regardless of the fact i track a lot, I have always ran SRF in all my cars since 2003. My daily was a BMW M5.

If not tracking, changing it once a year is enough to never have any issues. It would only ever be an issue if the car was stored for 3 months without being driven. We only get summer here. We had winter once, i think it was a Tuesday. 🤣.

I have never experienced brake fade since running SRF.

I boiled the stock fluid in my brand new GTS in the first week i owned it on the street. Changed to SRF, no matter how much i daily or track, never happened again.

 

How does on boil their brake fluid? I’ve never heard of that happening. Thanks

 

Having Fun at the Track!