DNA air filter, Stage-2 cover and oil filter for R 1300 GS/GSA/RT

Air filters and oil filters aren't sexy tuning parts in the classic sense. You barely see them, they rarely come up in pub-talk, and yet they sit at two neuralgic points of the engine. The air filter determines how clean and how low-resistance the combustion air reaching the engine is. The oil filter determines how pure the lubrication circuit stays as the boxer works under load, heat and revs.

This is especially interesting on the BMW R 1300 GS, because the 1,300cc boxer is no weak starting point. BMW quotes 145 hp at 7,750 rpm, 149 Nm at 6,500 rpm, 1,300 cc displacement and Euro 5+ as the technical basis for the R 1300 GS. The R 1300 GS Adventure lists the same core figures on its spec sheet - albeit with a somewhat different vehicle concept and higher touring ambition. The new R 1300 RT also uses the 1,300cc boxer with 145 hp and 149 Nm, though in a touring environment with a different fairing, different use case and different soundscape.

That's exactly why this 1000PS Performance Check is not an attempt to suddenly turn the GS into a superbike. It deals with the sober question: does high-quality filter technology on a modern BMW boxer actually make a noticeable difference? Where are the technical advantages, and what do you need to watch out for in everyday use?

Unboxed, the DNA setup doesn't look like a show part but like a functional performance addition - which is meant entirely as a compliment. The DNA air filter doesn't derive its effect from shiny decoration, but from material, filter surface area, sealing and airflow guidance. With the Stage-2 kit, it's not just the filter that takes center stage, but the combination of filter and airbox cover. The manufacturer lists the kit as the DNA Air Filter & Cover Combo P-BM13E24-S2-COMBO.

The feel of the two air filter elements, also available separately under the designation DNA Air Filters Set P-BM13E23-01_SET, matches the premium claim. Technically interesting is the special 45-degree design of the filter elements. According to DNA, this geometry is based on the flow conditions of the stock airbox and is intended to guide air as efficiently as possible toward the intake tract. For the DNA air filter for the BMW R 1300 GS, the manufacturer also uses four layers of cotton fabric and a factory-tuned oil treatment. To seal against the stock airbox, the polyurethane sealing surfaces are treated with the included DNA Sealing Grease. The stated filter efficiency is 98 to 99 percent. Combined with the DNA Stage-2 airbox cover, airflow is said to increase by 41.20 percent compared to the stock BMW solution.

The DNA oil filter DNA-162 is the less flashy part of the package, but for everyday servicing it's almost more important. Within the R-1300 family it shows up on, among others, the R 1300 RT and R 1300 GS Adventure, with 62 mm height, 56 mm diameter, cartridge design and road, off-road and race use. This isn't about show, but about clean oil flow, reliable filtration and a wear part you'll be handling anyway at every oil change.

The DNA Stage-2 kit isn't simply another filter element. It intervenes more heavily in the air routing, because it replaces the stock plastic intake area, or OEM intake duct. DNA promises that the Stage-2 kit delivers not only a punchier intake sound but also a noticeably freer airflow. Combined with the matching DNA air filter, airflow, power, torque and throttle response are all supposed to improve, while the high filter efficiency is retained.

The most important measured value is airflow. 6,024 l/min stock versus 8,500 l/min DNA Stage 2 means, according to DNA, a plus of 41.20 percent. That's not a feeling, it's a clear figure. At the same time, an airflow figure isn't automatically a dyno chart at the rear wheel. More air primarily just means less resistance in the intake tract. Whether that translates into more torque, more power, or just a more direct throttle response depends on load, rpm, temperature, engine management and ultimately also fuel mapping.

DNA itself points out that very impressive results are possible with an adapted fuel and engine tune. But this is also exactly where the honest limit of our Performance Check lies. We deliberately limited ourselves to the plug-and-play conversion and tested the Stage-2 kit without an individual ECU remap, which probably corresponds to the use case of many ambitious road riders. However, anyone wanting to exploit the full potential of the freer intake tract cannot avoid a professional tune.

The manufacturer's or distributor's claim of roughly plus 5 hp in the mid-rpm range fits this technical logic, but shouldn't be read as our own 1000PS dyno figure. On the road, such a gain is noticeable more in pull and in picking up from mid-range revs than in whether the top of the chart reads 145 or 150 hp.

For its high-performance air filter, DNA uses a multi-layer, oiled and, according to the manufacturer, flame-retardant cotton medium with FCd design technology. However, there is far more behind this concept than just the largest possible filter surface area. For the BMW R 1300 GS, DNA developed the filter elements with a special 45-degree geometry. This was based on an analysis of the stock airbox, which found that intake air in this area follows exactly this flow pattern. The shape of the filter elements was therefore deliberately matched to the original air routing, in order to guide airflow as efficiently and evenly as possible toward the intake tract. On a modern boxer with ride-by-wire and sensitive fuel injection, it's not just the quantity of intake air that matters, but also its controlled flow. A cleanly guided airflow can have a positive effect on throttle response, responsiveness and torque build-up.

At the same time, maintenance must be taken seriously. An oiled cotton filter requires careful cleaning and regular re-oiling to permanently retain its filtering properties. A neglected sports air filter is no longer a performance part, but a risk. For the Stage-2 set, the installation instructions recommend servicing every 15,000 km - or sooner in very dusty conditions - along with the DNA Service Kit DSK-3001 for cleaning and re-oiling.

The DNA-162 oil filter doesn't bring a louder airbox and no noticeable kick when you crack open the throttle - its job is less emotional, but no less important. Motor oil carries abrasion, combustion residue and tiny particles that the filter must reliably capture without unnecessarily choking oil flow. Especially on long stints, high oil temperatures, spirited road riding or off-road dust, that's no side issue.

DNA describes its premium motorcycle oil filters in general as designed for high oil flow, good filtration, OEM standards and compatibility with synthetic, conventional and semi-synthetic oils. DNA also mentions, depending on application, a specially engineered bypass or pressure-relief valve. In practice this means: the oil filter is not a tuning part in the classic sense, but a quality component in the maintenance schedule. Here you're not primarily buying horsepower, but engine protection, clean oil flow and a good feeling at service time.

From a value-for-money perspective, the oil filter is therefore the most rational decision in the whole package. A filter has to go in at every oil change anyway. If the DNA-162 is priced close to other quality brand-name filters, that's not an extravagant upgrade but a deliberate choice for quality.

The conversion itself isn't rocket science, but it's also no moment for sloppiness. When changing the air filter on the R 1300 GS, cleanliness beats speed. Once the air filter box is open, no dirt may fall onto the clean side of the airbox. This is exactly what the clearly laid-out installation instructions point to as well. The stock air filters and covers are removed - the original plastic covers are not reused in the Stage-2 conversion - after which the DNA filters, greased at the seals, and the Stage-2 airbox cover go in. The screws must not be overtightened.

One more important note here: a sports air filter can be as good as it wants - if dust or dirt falls into the intake tract during installation, you've ruined your own argument. Anyone who works carefully here ends up with a clean, reversible performance modification after the conversion. Anyone who rushes is gambling with the most expensive component on the bike.

With the oil filter, it's classic service routine. The DNA-162 belongs at the oil change, so with the correct oil, correct fill level, clean sealing surface and prescribed torque. Here too the rule applies: it's not the filter that makes a good service, it's a clean service that makes the filter effective.

Our test rider Arlo deliberately settled for the plug-and-play conversion. No individual tune, no attempt to turn an adventure bike into a race bike. The question was: do you feel anything on the road when the R 1300 GS is allowed to breathe more freely?

Arlo's short version was dry and pretty spot-on: "You feel a small plus down low. No brutal hit, no completely different engine, but a touch more willingness when you get back on the throttle out of the rev-cellar. Especially accelerating out of tight corners, casually overtaking, or picking up again at corner exit, the boxer feels a bit more alert. Not more aggressive, not more nervous, just a notch more immediate."

The second point is the intake noise. It's more present, but not embarrassing. Arlo described it the way you would after a good run on the road: "That slight intake hiss is pretty damn cool. That's exactly where the appeal lies. Not in the noise, but in the mechanical breathing. You can hear that more is happening up front and under the tank, without the GS turning into a racket box."

The classification is important: the Stage-2 kit doesn't automatically make the BMW faster in the sense of a significantly higher top speed or a spectacular increase in peak power. It makes it livelier during normal riding, if you're open to such nuances. Anyone who knows the boxer and pays attention to throttle response, intake tone and fullness in the low to mid range will notice the difference.

On the road, the louder airbox noise is largely swallowed up within the overall soundscape. Tires, wind, boxer, helmet, exhaust, traffic: the GS doesn't turn into a rolling loudspeaker because of it. That's a pleasant finding, because many open intake solutions quickly sound cheap. Here the impression stays mature.

Still, the open or modified intake area isn't automatically harmless. DNA itself lists the Stage-2 kit as "Race use only." That settles the central point for road use. Whether you should ride the open cover on the road doesn't just depend on your personal noise tolerance, but on registration, roadside checks, insurance and regional legal situation.

Our impression is: it doesn't become a racket box. But an attentive officer, possibly even with GS experience, could theoretically notice the modified intake tract. That's the flip side of a conversion that brings more air and more intake character, but isn't offered as a road-legal comfort accessory.

The three DNA products pursue different goals and therefore appeal to different riders.

The DNA oil filter (DNA-162) is the most sensible and uncomplicated solution in the package. It belongs at every service anyway and appeals to riders who value quality in maintenance parts. Its benefit isn't more power, but a high-quality component for long-term engine protection. High-mileage riders, tourers, and owners of a GS or RT with high annual mileage are probably the right target group here.

The DNA air filter (P-BM13E23-01_SET) is the next step for riders who want to treat their boxer to somewhat higher-quality filter technology. It replaces the stock filter, is reusable and can be cleaned. At the same time it provides freer airflow, and thus suits riders who want to technically optimize their machine without deeply altering the engine's character. Anyone who's regularly on the road and takes their maintenance seriously gets a sensible quality upgrade here without major drawbacks.

The DNA Stage-2 kit (P-BM13E24-S2-COMBO), on the other hand, targets a considerably more specific group. Here it's no longer about maintenance or replacement, but about performance. Riders who want to let the boxer breathe more freely, who enjoy a sportier intake note and want to squeeze the maximum out of their bike will find the most exciting solution here. The kit becomes especially interesting for ambitious riders and competition riders who have their bike individually tuned anyway.

The Stage-2 kit is less suitable for riders who want to keep their BMW as close to stock as possible, or who value maximum inconspicuousness. For that group, the DNA air filter and DNA oil filter are the more sensible choice. They offer high-quality filter technology and focus on quality and longevity rather than maximum performance.