Sprint Filter P08 Air Filter for Road & Track – KTM 250 Duke (2015–2016) PM145S

The 250 Duke sat in the middle of a family that shared one airbox between four displacements, and that is more interesting than it sounds. The box, its aperture and the element inside are the same item from the 125 up to the 390; what changes from one machine to the next is how many litres a minute have to pass through the same piece of cloth. A filter designed with that spread in mind is a different object from one sized to a single engine, and it is why one element code covers so much ground here.

Key Features

• One element, nine machines: the whole first small-capacity range shares this airbox
• Woven polyester used dry — 80 µm, 5,050 l/m²/sec, and no oil anywhere in the routine
• Filtering surface roughly double that of other performance elements, which is where the margin comes from
• Threads from ø 22 micrometres upward: that figure is the thickness of the yarn, not the size of the openings
• A straight swap for the paper panel — no airbox work, no remap
• Washable and reusable for the life of the bike, with a two-year warranty from purchase

Same aperture, different appetite

Flow through a filter medium is quoted per square metre — 5,050 litres per square metre per second for this one — so how much air an engine can draw through a given box depends on how much cloth has been folded into it. Doubling the area does not double anything the engine does. It lowers the pressure the engine has to pull against for the demand it already has, and it pushes back the point at which accumulated dirt starts to matter. Across a family that runs from 125 to 390 cc through one aperture, that margin is what makes a single part number honest rather than lazy.

Where the gain shows and where it does not

It does not show on a dyno. A replacement element in an unmodified airbox is not a power part on any standard road machine, and the 250 Duke is no exception. It shows in how little the intake changes between services: a paper panel loads, its pleats deform and it stops passing air evenly, whereas a dimensionally stable weave that you wash returns to the same condition every time. Dull, measurable, and true for as long as you own the bike.

Care and cleaning

Blow it through from the clean face outward with an air line; after most seasons that is enough. For an element that has genuinely loaded up, hand-warm water and a mild detergent will release the rest — rinse until the run-off is clear, then leave it somewhere with moving air until it is dry all the way through. No hairdryer, no oven, no flame, and nothing applied to it afterwards. Downloads holds Sprint Filter's own sheet for the PM145S.

Fitment & Compatibility

The P08 element for the KTM 250 Duke, 2015 and 2016 — a short production run inside a long-lived family. Nine machines share this element, and the Fitment tab lists each of them with the years it applies to.