I have a 2015 V8S with the standard performance pack brakes. What brake fluid is everyone running on the track? Jaguar specs: "Use Jaguar brake fluid. If unavailable for topping up, a Low Viscosity, DOT4 brake fluid that meets the requirements of ISO 4925 class 6 may be used." I usually run Motul RBF 600 in my other cars. Which is normal viscosity. But this is my first time seeing Low Viscosity. Will there be issues running normal viscosity fluid and daily driving on the street? How touchy is the ABS system? Motul also has a DOT 5.1 that is low Viscosity, but I have no experience with DOT 5.1.

Thanks in advance for the help!

 

I yet to have my OEM fluid boil on the track, but where I live summer temperature usually in 80-90F range.

I was told not to mix different specs of fluid, as they could chemically react with each other. So if you decide to try a different type of fluid (not a good idea IMO), make sure to fully flush the old fluid out of the system first.

 

+1. Stick with the recommended specs.





$13/liter online if you hunt for it. $60 if you don't.

 

Perfect! This is just what I was looking for. Thanks! Any idea how much fluid the factory system takes on a full flush?

 

I've been right through the Workshop Manual and nowhere does it say what the full volume of brake fluid is or should be, all it says (many many times!) is "fill the reservoir to the MAX mark".
But having had a full flush and replace done a bit over two months ago, where I supplied two new 500 ml bottles of fluid and got one back, I would say that 500 ml is enough.
Also, the specified fluid according to the Workshop Manual is SHELL DONAX YB DOT4 ESL FLUID but I have been using Nulon "Super Dot 4" without any problems at all (Nulon is an Aussie brand), and I reckon any quality Dot 4 or Dot 5.1 will be perfectly OK. Just don't use Dot 5, as it's a different base to Dot 4 and Dot 5.1, silicone vs glycol, and you must never mix the two.

 

Don't forget, the book specifies DOT 4 Class 6. Ordinary DOT 4 may not be adequate. I don't know enough about 5.1 to weigh in.

 

One of the best is MOTUL RBF 660 BRAKE FLUID

https://www.motul.com/us/en-US/produ...0-factory-line

 

Note that "Low Viscosity" is specified. If that's not on the label, keep looking. When I was last looking (over a year ago) my local auto parts only carried Pentosin Low Viscosity.

 

My preference is Endless RF650

 

FWIW - On BMW forums, I've read that for street use stick with low viscosity fluid if that is what manual calls for. For a track car only, then go normal viscosity. The logic being at higher track temps the low viscosity fluid becomes too thin. Conversely, on a street car the lower viscosity fluid works best as it allows the abs to react faster than the normal viscosity would.

So since I rarely make it to the track, I'm going with low viscosity - just ordered the ATE fluid on amazon, $14 delivered including tax...