Sprint Filter T12 Air Filter for Off-Road & Extreme – BMW R 1200 RS (2015–2018) K142T12

Two of the three numbers on this element's specification are properties of the material and one is a property of the part. Seven microns and 560 l/m²/sec describe the mat itself and are identical on both versions Sprint Filter sells for this airbox. The hundred per cent the catalogue credits to this part number describes how much of that mat is in the box. Reading the three together is the whole of the buying decision, and reading them wrongly is how a filter gets sold as something it is not.

Key Features

• Polyester special non-woven, dry, filtering to 7 microns
• A rated 560 l/m²/sec — a rate per square metre, not a throughput of the part
• Catalogued with a hundred per cent more filtering surface than the standard-size version
• Carries no oil at any stage of its life, before or after washing
• Fits the series airbox exactly as the factory panel did, with no mapping change
• Serviced with an air line for the life of the machine; two years of guarantee

What a per-square-metre figure means

Flow ratings here are quoted for a square metre of material and a second of time, which is the only way a medium can be described independently of the shape it is cut into. Put twice as much of the same mat in front of the same engine and the mat has not changed at all — it still passes 560 litres per square metre and second. What changes is the sum: twice the area at the same rate is twice the air the element can pass before the material becomes the limit, and twice the dust it takes on board before resistance climbs.

And what does not change

Retention. Not by a micron. The element does not become finer because it became larger, so anything a seven-micron mat lets by it still lets by. Nor is there any power in it. An air filter inside an unmodified airbox does not make a standard R 1200 RS noticeably faster whatever its size, because intake, injection and exhaust were developed together and a panel sits inside that work. What the doubled area buys is a longer stretch of unchanged behaviour between services, and on a strict medium that stretch is the thing worth having.

Care and cleaning

The mat is regenerated rather than consumed. An air line laid against the clean side and worked outwards lifts the load back out the way it entered, and on the extreme medium that is a job worth doing often rather than thoroughly once. Hand-warm water and a hint of mild detergent take over where air stops helping, and the rinsing goes on until nothing further colours the water. Drying is the step with no permitted shortcut: moving air only, no warmth, no flame, no impatience, and the K142T12 goes back dry with nothing added to it. The Sprint Filter servicing sheet is under the Downloads tab.

Fitment & Compatibility

For the BMW R 1200 RS built from 2015 to 2018, seated in the standard housing with nothing modified. The part number is catalogued for six machines in all — the five 1200-generation boxers and the R 1250 GS — each with its own years in the Fitment tab.