Sprint Filter T12 Air Filter for Off-Road & Extreme – BMW R 1250 GS (2019–2023) PM142T12

The dirtiest air a GS ever draws arrives while it is barely moving. Trail speed on a dry track, a line of machines each riding in the plume of the one ahead, a halt with the engine running while everything stirred up on the way in is still hanging there — that is when the load on an element is at its worst. It is also, and this is the useful part, when the engine is asking for less air than at any other point in the day. The extreme medium gives up flow precisely where flow is cheapest.

Key Features

• Special non-woven polyester, dry, closing to 7 microns
• A rated 560 l/m²/sec against 5,050 for the standard cloth in the same housing
• Never oiled, so there is no film to migrate onto the intake sensors
• Something close to twice the filtering surface of other performance media
• A direct exchange for the factory element, with the airbox and the map untouched
• Cleared with an air line instead of discarded, and warranted for two years

Two curves that happen to be out of phase

Demand for air rises with engine speed; airborne dust rises when speed over the ground falls. On a fast sealed road the engine is drawing hard through comparatively clean air; on a piste in first and second gear it is drawing modestly through the worst air of the trip. A restriction is paid for wherever demand is high, so a medium chosen for the second situation is charged least in the very situation it was chosen for. That does not make the restriction vanish on the fast road home, with the same element still in the box — it makes the trade a favourably shaped one rather than a straight loss.

The size of the trade

It is the largest in the range and deserves naming precisely: 560 l/m²/sec against the standard weave's 5,050, so roughly one ninth of the air through an equal area of material, in exchange for closing from eighty microns down to seven. Finer means stricter and never simply better, and the two figures always travel together in opposite directions. None of it is a power question either. A PM142T12 inside the standard airbox makes a standard R 1250 GS no quicker than it was; the whole of the gain sits on the filtration side of the ledger.

Care and cleaning

Everything the element needs is a compressor and a little patience. Air is applied to the face that looks at the engine and driven outwards until the surface is open again; from the dirty side it would only be pressed home. After a genuinely filthy few days, hand-warm water with a mild detergent takes over and the element is rinsed through until nothing more leaves it. Drying is done in open air only and is not to be hurried, since heat guns, ovens and flames finish polyester for good, and it returns to the housing dry with nothing applied to it. The Sprint Filter servicing sheet is filed in the Downloads tab.

Fitment & Compatibility

For the BMW R 1250 GS of 2019 to 2023, in the unmodified series airbox. Three machines carry this element and all are GS models: this one, plus the R 1200 GS and the GS Adventure that came before it. Their years are listed in the Fitment tab.