Fox 4wt Fluid Replaces Fox 5wt PTFE Fluid

Fox's 4wt Suspension Fluid isn't a new product, but now it's got a new home inside all of Fox's GRIP style dampers.

Fox has quietly made a rolling change to the fluid used in a number of their suspension products, and we're here to tell the world. Fox 5wt PTFE Infused Fluid has been used in all GRIP and GRIP2 equipped forks since their release, but now that's changing! Fox is replacing it with their 4wt suspension fluid everywhere that 5wt has been used, and the old 5wt PTFE fluid is being completely discontinued. Fox's 4wt isn't a new fluid, it's been used in their high performance shocks for years now, and is a higher quality fluid than the 5wt it's replacing.

The Fox 4wt Suspension Fluid is now used in the following products:

• Fox DHX2 (2021+)
• Fox DHX (2021+)
• Fox Float X2 (2021+)
• Fox Float X (2021+)
• Fox Float & Float SL (2024+)
• All MY2025+ Fox and Marzocchi forks with GRIP, GRIP X, GRIP X2, GRIP SL, or Rail dampers.
• All previous generation Fox and Marzocchi forks that used 5wt PTFE Infused Fluid

All 2025+ Fox and Marzocchi products will ship with the 4wt Suspension Fluid in the damper side bath chamber, and when servicing these new forks, just keep using the 4wt Suspension Fluid. Don't get creative and mix and match the old 5wt PTFE Infused Fluid, just stick with the 4wt fluid.

All previous generation Fox products with 5wt PTFE Fluid will now get filled with 4wt in its place. You shouldn't throw away all of your 5wt PTFE Fluid if you have a stock pile, but once you run out just replace it with 4wt Fluid. You don't need to scour eBay and overpay for the discontinued 5wt!

When you're servicing your fork at home and filling it with 4wt for the first time, you don't need to worry about getting absolutely all of the 5wt out first. Just drain it like you would normally and then fill it with the 4wt fluid as directed on our MTB Suspension Fork Oil Volume Charts. Nothing else is changing in the service process and the service intervals of the forks are not changing either.

Here at The Lost Co, we've adapted to the change and all Fox fork services are now getting the 4wt treatment!

Got questions? Feel free to shoot us an email or give us a call!

(360) 306-8827

sales@thelostco.com