Cleaning machines

Choose car cleaning machines by the job they do and the supply they need

What are cleaning machines in car care? Machines that move dirt with water, suction, compressed air or airflow instead of a cloth: pressure washers, vacuums, air cleaning guns and blower dryers. You choose by the step in your wash and the supply you have, not by the biggest number on the box.

Cleaning machines in car care are the machines that lift or pick up dirt without a cloth wiping across the surface. Outside, the pressure washer rinses loosened dirt off the paint; inside, the air cleaning gun blasts dust out of carpet and seams for the vacuum to pick up, and a blower dryer chases leftover water out of gaps. The chemistry does the loosening, the machine does the carrying away.

• Four machine families for four jobs. Water rinses the outside, compressed air loosens the inside, suction picks up, and airflow dries the gaps. At every one of those four points, a cloth or mitt would otherwise drag grit across the surface.
• More bar doesn't mean more water. Kränzle rates its pro unit, the Profi 160 TST, at up to 140 bar working pressure and 11 litres per minute, which works out at 660 litres an hour. bigboi quotes up to 179 bar maximum pressure and 7 litres per minute for the compact WashR Flo. On the box, the small machine wears the bigger bar figure; the pro machine moves more water to rinse with.
• Every machine lives off its supply. The pressure washer needs a water feed and a socket, the cleaning gun needs a compressor, and FLEX also builds vacuums and blowers for 18-volt batteries. Sort out the supply before the machine, and you won't buy something your own wash spot can't keep up with.

Detailing1's day-to-day tip: Deionised water only belongs in the final rinse. According to bigboi, a 20-inch resin cartridge delivers 1,200 litres at 0 ppm, based on tap water at 100 ppm. ppm counts the dissolved minerals, in other words whatever gets left behind as a water spot once the car dries. Swap the resin when the meter hits 15 ppm, sooner if your water is harder. Wash with tap water, deionise only the last pass, and the resin lasts longer while the car dries off spot-free.

Water and air shift the dirt before a towel ever touches the paint

Cleaning machines move dirt with water, suction, compressed air or airflow, and take over exactly the steps where a cloth would otherwise drag grit across the surface.

Road grime isn't a fine powder. It carries sand, grit and brake dust, and every grain a wash mitt drags across the clear coat leaves a trail. Those trails are swirls: fine, circular scratches that light up when low sun rakes across the paint. They appear wherever grains get pushed across a surface under pressure.

That's exactly why the machines go first and the towel second. The rinse knocks loose grit off before a mitt ever touches the paint. Inside, compressed air loosens the sand in the carpet and the vacuum picks it up, instead of a cloth grinding it deeper into the pile. The blower chases leftover water out of mirrors, seams and badges, where a towel struggles to reach.

The jobs stay separate: chemistry loosens, the machine carries it away. No cold water jet cracks a film of grease, and no vacuum pulls baked-on dirt out of upholstery. Treat the machine as a stand-in for the cleaner, and you end up cranking the pressure and creeping closer to the paint. Treat it as the transport, and you prep first, then take your time rinsing off.

If you're just getting started, you don't need all four machines at once, and none of them replaces a clean order of work. If you detail several cars, on the other hand, every touch a machine takes over counts. Each one is one less chance for swirls you'd have to polish out later.

Outside it's all water; inside, suction and compressed air take over

Outside, the pressure washer carries loosened dirt away with water; inside, the vacuum and the air cleaning gun split the work, and the blower dryer handles leftover water after the wash.

In pressure washers, the range runs from Kränzle cold-water machines, such as the portable Kränzle "K 1050 P" or the Kränzle "K 1050 TST" with its hose reel, to compact detailing units from bigboi. According to bigboi, the WashR Flo ships with a foam lance. On top of that come guns, lances, nozzles and hoses for each machine.

For the interior, two machines work side by side. The vacuums range from FLEX safety vacuums with a dust class, through 18-volt cordless models, to the bigboi SuckR Pro wet and dry vac. For upholstery, the range carries the bigboi XtractR Mini as an extraction vacuum. If you're after an upholstery cleaning machine, this is the type you'll end up with; how spray extraction works and when it's worth it is covered under vacuums.

The air cleaning gun backs up the vacuum rather than replacing it. The SONAX PROFILINE PowerAirClean is a siphon-cup gun: it runs on compressed air and cleaner from the cup, and loosens dirt where the vacuum nozzle can't get to. For leftover water after the wash there are blower dryers such as the bigboi BlowR range and the FLEX "BW 18.0-EC" cordless blower.

Accessories only fit the connection system of their own machine. Kränzle specifies the D12 quick-connect system for the Profi 160 TST, and bigboi lists its lances and guns specifically for the WashR Flo. So you buy a foam lance or nozzle for the machine, not for the brand, and check first which connection your gun has.

If you do interiors too, add the vacuum to the list. Lifts, lighting and fit-out for the rest of your space are in the Workshop overview.

The biggest number on the box tells you little about cleaning

Across all four machine families, the biggest number on the box isn't what decides it; each time, the figure that matters is a quieter one, such as water flow, dust class, air delivery or airflow.

On a pressure washer, pressure in bar takes centre stage, meaning the force with which the jet hits the surface. Flow rate in litres per minute, by contrast, describes the water that carries the loosened dirt away. At the socket, both share the same limited motor power. What that means for you: compare machines on litres per minute first, then on pressure.

In 2025, Stiftung Warentest, Germany's leading consumer testing organisation, tested twelve electric pressure washers and concluded that high maximum pressure doesn't determine the cleaning result; what counts is how pump and nozzle work together. It criticised short, stiff hoses, a point the performance figures on the box never show. Nozzles, lances and the performance maths are covered in detail under pressure washers.

With vacuums, it's the wattage. That figure describes the power drawn, not the suction at the nozzle. Dust class and wet rating matter more. The dust class, L or M on FLEX machines, tells you the maximum amount of fine dust the vacuum as a whole lets through. In practice: sanding dust from paint correction with tools such as random orbital sanders belongs in a vacuum with a dust class, not blown around the room. Only machines rated for wet pick-up can take liquid.

With the air cleaning gun, what counts is the compressor's free air delivery, meaning the air that actually reaches the tool. It sits below the intake figure, which is also on the spec sheet. With a blower dryer, airflow, nozzle and reach tip the scales, not the motor's wattage. In all four cases the same question helps: what actually arrives where the work gets done?

Tap, socket and compressor put a ceiling on every machine

Every cleaning machine hangs off a supply, and that supply sets the limit: the water feed for the pressure washer, socket or battery for the vacuum and blower, the compressor for the gun.

Without the right supply, every machine falls short of what it can do, and you only notice once you're mid-wash. A pressure washer needs at least as much water at the inlet as it's meant to deliver; for the Kränzle Profi 160 TST, that's the 11 litres per minute from the comparison above. If there's no tap handy, Kränzle says this machine can also draw straight from a tank, with a suction lift of up to 2.5 metres.

On the power side, the circuit rating is what counts. Kränzle specifies 230 volts at 14.3 amps and 3.2 kilowatts of power input for the pro unit, while bigboi says the WashR Flo gets by on 1,600 watts peak power. If you work at your wash spot off a long extension lead or a lightly fused circuit, sort that out before you buy. How to plan fusing, water feed and drainage is covered under Workshop equipment.

Vacuums and blowers can partly cut the cord. FLEX builds vacuums and the "BW 18.0-EC" blower for 18-volt batteries; if you already own batteries from that platform, you'll find chargers and spares under Battery systems. The cable goes, but the charge limits how long you can run in one go.

The air cleaning gun puts its own supply straight onto the shopping list. It only runs on a compressor that delivers enough air continuously, and a small cordless compressor isn't built for that kind of non-stop duty. Which type can handle it is covered under Compressors.

Foam lance, fan jet, blower and vacuum work in a fixed order

A machine-assisted wash follows a fixed order: foam for the pre-wash, fan jet for the rinse, blower and towel for drying, then brush, gun and vacuum for the interior.

In the pre-wash, pre-wash cleaner and snow foam, a thick cleaning foam, go on after the first rinse. A foam like Koch-Chemie Gentle Snow Foam "Gsf" goes on through the foam lance, so the active ingredients don't run straight off the doors and sides. Without a pressure washer, a pump foam sprayer like the iK Sprayers "iK Foam" Pro 2 lays the foam down; you still rinse with water afterwards. Chemistry and order are covered under Pre-wash.

Rinsing is a job for the fan jet. ADAC, Germany's largest motoring club, recommends keeping 30 cm from the paint, and in a DEKRA test series the tyre came through a 25-degree fan jet undamaged from 25 cm, even with long exposure. Rotary and pencil-jet nozzles, on the other hand, damaged the tyre; they have no business on paint or rubber. You can do the last pass with deionised water, as described in the tip above.

When drying, blower and towel split the work. A blower dryer chases water out of mirrors, seams, badges and the grille, while a big drying towel like the Koch-Chemie Pro Drying Towel 950GSM takes care of the panels. GSM stands for grams per square metre, the weight of the microfibre. More towels and drying aids are under Drying.

Inside, a brush or the air cleaning gun first loosens whatever's sitting in vent slats, seams and carpet pile, then the vacuum picks it up. Detailing brushes like the SONAX PROFILINE PinselSet free the dust before the vacuum nozzle moves in. The full interior order is in our guide Cleaning your car interior.

The first time round, this routine takes noticeably longer than a quick wash with a sponge. That's part of the deal. With every pass your hands get surer, and the order becomes second nature you no longer have to think about.

For the occasional rinse, a self-service wash bay does the job

If you only rinse your car now and then, you don't need your own pressure washer; a self-service wash bay will do, as long as you bring decent chemicals and keep your distance from the paint.

A self-service bay is the wash spot where you wash the car yourself with the site's own lance. Your own machine pays off once you regularly pre-wash with foam or want to give wheels and arches a thorough rinse. Before that, check your local rules: in Germany there's no single nationwide rule for washing a car on your own property; water law and local bylaws decide. On unsealed ground and in water protection zones it's banned.

For the interior, a vacuum you already own plus a brush for vents and seams is enough to get going. The air cleaning gun only comes in once a suitable compressor is in place. The blower dryer is the add-on for anyone who washes regularly and is done chasing leftover water out of mirrors and seams with a towel.

If you detail for a living, factor in a legal duty. In Germany, pressure washers used in a business are inspected by a competent person before first use, after safety-related repairs, after more than six months out of service, and at least every 12 months. This inspection rule doesn't apply to washing your own car.

One gap belongs in the picture too: we found no independent test rating for the Kränzle and bigboi machines or for the FLEX vacuums, and neither a Kränzle nor a bigboi unit was part of the Stiftung Warentest pressure washer test. The selection therefore rests on manufacturer data and on the figures that actually reach the car while you work.

In the end, each of these machines takes one step away from the towel, and with it a moment where grit could travel across the paint. So what should decide your pick isn't the biggest number on the box, but the supply that really reaches your wash spot: water, power and air.