Karcher K4 vs K5 Pressure Washer: In-Depth Comparison

If you’re looking for a decent pressure washer to clean cars, bikes, patios and furniture, then the Karcher K4 and Karcher K5 are well-worth considering, but which is the best choice? Is the K5 worth the extra money? In this article, I’ll directly comparing the Karcher K4 and K5 pressure washer models (and variants e.g. compact, power control, home etc.) so you can figure out which is the best option for you.

Karcher K4 vs K5 Summary

The Karcher K5 has a higher flow rate and maximum pressure rating in addition to a longer hose compared to the Karcher K4. Both models are similarly sized and come with two nozzles, a 5 meter mains cable and quick connect system. The K4 is cheaper than the K5 pressure washer.

SpecificationKarcher K2Karcher K4
Maximum Pressure130 bar145 bar
Maximum Flow Rate420 litres/ hour500 litres/ hour
MotorAir-Cooled on Compact and Water-Cooled on Power Control VersionWater-Cooled on all versions
Hose Length6m for Compact and 8m for Power Control Model8m for Compact and 10m for Power Control Model
Compact Version Weight4.7 kg12 kg
Power Control Version Weight11.5 kg13.0 kg
Karcher K2 vs Karcher K4 Pressure Washer

K4 Power Control

K5 Power Control

Images link to Amazon

Pressure and Flow Rate

Let’s start off with the most important specifications, flow rate and pressure, as these have the biggest impact on the performance of each device.

The Karcher K5 is a more powerful machine than the Karcher K4 as it has a higher maximum pressure rating and maximum flow rate. The Karcher K5 has a flow rate of 500 L/ hour and maximum pressure of 145 bar. The Karcher K4 has a flow rate of 420 L/ hour and maximum pressure of 130 bar.

This means the Karcher K5 produces 11.5% more pressure and has a 19% great flow rate in comparison to the less expensive Karcher K4 pressure washer.

Both machines are very powerful and capable of cleaning cars, outdoor furniture and patio flags. The extra power of the K5 can come in handy when cleaning patios and fences, but won’t make a huge difference when just cleaning a car.

The only time you’ll really notice a benefit of the increased pressure and flow rate of the K5 for car cleaning is when using a snow foam cannon, as this increased power will mean thicker foam is produced. However, it’s still possible to get very thick foam with a Karcher K4, especially if you’re using a good quality foam cannon.

Comparing Sizes

There are a few versions of the Karcher K4 and K5 which come in different sizes. The K4 has two variants: power control and compact. Whereas the K5 has three variants: power control, premium smart control and compact.

The K4 Compact model is the smallest followed by the K5 Compact model. The K4 Power Control is larger but slightly lighter than the K5 Compact. The K5 Power Control has the same dimensions but is heavier than the K4 Power Control. The K5 Premium Smart Control is the heavier pressure washer and is slightly longer compared to the K4 and K5 Power Control models but it’s the same width and height.

Here are some tables to show the differences between each model in terms of their dimensions and weight.

Metric Units

Karcher ModelLengthWidthHeightWeight
K4 Compact27.3 cm25.6 cm45.7 cm4.7 kg
K5 Compact35.4 cm30.8 cm52.0 cm12 kg
K4 Power Control40.2 cm30.6 cm58.8 cm11.5 kg
K5 Power Control40.2 cm30.6 cm58.8 cm13.0 kg
K5 Premium Smart Control41.4 cm30.6 cm58.8 cm13.9 kg
Karcher K4 and K5 Series Pressure Washer Dimensions (Metric Units)

Imperial Units

Karcher ModelLengthWidthHeightWeight
K4 Compact10.7”10.1”18.0”10.4 lbs
K5 Compact13.9″ 12.1″20.5″ 26.5 lbs
K4 Power Control15.8”12.0”23.1”25.4 lbs
K5 Power Control15.8”12.0”23.1”28.7 lbs
K5 Premium Smart Control 16.3″12.0″ 23.1″30.6 lbs 
Karcher K4 vs K5 Power Control and Compact Pressure Washer Dimensions (Imperial Units)

Other Important Differences

As well as the K5 being a more powerful model compared to the K4, there are also a few other differences between the machines. The most notable being:

  • The K5 has a aluminium telescopic handle whereas the K4 has a plastic telescopic handle.
  • The K5 has a higher power rating of 2100W compared to the K4 which has a rating of 1800W so the K5 will use slightly more electricity.
  • The K5 has a longer hose compared to the K4.
Karcher ModelHose Length (metric)Hose Length (imperial)
K4 Compact6 meters19.7 ft
K5 Compact8 meters26.2 ft
K4 Power Control8 meters26.2 ft
K5 Power Control10 meters32.8 ft
K5 Premium Smart Control10 meters32.8 ft

The 6 meter hose on the K4 Compact can be a bit limiting, and the 10 meter hoses found on the most expensive K5 Power Control and Premium Smart Control models in my opinion are a huge upgrade. However, keep in mind that you can purchase higher quality and longer hoses on the aftermarket which I would recommend doing personally.

Model Variations (Compact, Home etc.)

There are several variations of the K4 and K5 models which can be very confusing.

Karcher K4 Variants:

  • Compact
  • Power Control
  • Premium Power Control

The Compact model is lighter and smaller compared to the similarly sized Power Control and Premium Power Control. The main difference between the Power Control and Premium Power Control models is that the latter has an integrated hose reel. All models have the same pressure and flow rate. Here is a table highlighting the other key differences.

Karcher K4 ModelHose LengthMotorDetergent ApplicationTriggerIntegrated Hose Reel
Compact6 meterAir-CooledSuctionStandardNo
Power Control8 meterWater-CooledPlug and CleanLED DisplayNo
Premium Power Control8 meterWater-CooledPlug and CleanLED DisplayYes
Karcher K4 Compact vs K4 Power Control vs Premium Power Control

K4 Compact

K4 Power Control

K4 Premium Power Control

Images link to Amazon

Karcher K5 Variants

  • Compact
  • Power Control
  • Premium Smart Control

The K5 Compact has an air-cooled motor which is not as durable as the water-cooled motor on the Power Control and Premium Smart Control models and it also has a shorter hose. The Premium Smart Control model is the only K5 with an integrated hose reel and Bluetooth compatibility which allows you to control the pressure washer using an app. All models have the same pressure and flow rate and have a water-cooled motor.

Karcher K4 ModelHose LengthDetergent ApplicationTriggerIntegrated Hose ReelBluetooth Compatible
Compact8 meterSuctionStandardNoNo
Power Control10 meterPlug and CleanLED DisplayNoNo
Premium Smart Control10 meterPlug and CleanLED DisplayYesYes
Karcher K4 Compact vs K4 Power Control vs Premium Power Control

K5 Compact

K5 Power Control

K5 Premium Smart Control

Images link to Amazon

Home and Car Versions

The only other variants that need to be addressed are the “home” and “car” models which are the exact same as the standard models but have extra accessories:

  • Home: patio cleaner and detergent also included.
  • Car and Home: patio cleaner and detergent, rotating car wash brush, foam jet and shampoo.

Whilst the “home” accessories can be quite useful, I strongly advise against using the car accessories.

These accessories are poor quality and the brush in particular will cause scratches in the paintwork. I always recommend using a microfiber wash mitt instead of a sponge or brush if you don’t want to ruin the car’s finish!

You can also find much higher quality foam cannons and car shampoos from dedicated car cleaning stores. Check out my car cleaning product recommendations if you’re looking for some suggestions.

Similarities Between the K4 and K5

  • Two nozzles: the vario lance and dirt blaster lance.
  • Quick connect on the machine for the hose.
  • All models have a 5 meter main cable.
  • The maximum water feed temperature is 40°C.
  • The minimum pressure is 20 bar.

Specification Rundown

FeatureK4 CompactK4 Power ControlK5 CompactK5 Power Control
Current Type230-240 V230-240 V230-240 V230-240 V
Minimum Pressure20 bar20 bar20 bar20 bar
Maximum Pressure130 bar130 bar145 bar145 bar
Max Flow Rate420 L/ hour420 L/ hour500 L/ hour500 L/ hour
Area Performance30 m2/ hour30 m2/ hour40 m2/ hour40 m2/ hour
Water Feed Max Temp40°C40°C40°C40°C
Power Rating1800 W1800 W2100 W2100 W
Power Cable Length5 meters5 meters5 meters5 meters
Hose Length6 meters8 meters8 meters10 meters
Weight (without accessories)4.7 kg11.5 kg13 kg 13.0 kg
Dimensions (L x W x H) 27.3 x 25.6 x 45.7 cm40.2 x 30.6 x 58.8 cm40.2 x 30.6 x 58.8 cm40.2 x 30.6 x 58.8 cm
MotorAir-CooledWater CooledWater-CooledWater Cooled
Detergent ApplicationSuctionPlug and Clean SystemSuctionPlug and Clean System
LED Display on TriggerNoYesNoYes
Telescopic HandleNoPlasticNoAluminium
Quick Connect on MachineYesYesYesYes
Karcher K4 vs K5 models

Check out my complete guide to the Karcher pressure washer range to find out all the differences between each model.


I first became interested in car detailing around 3 years ago and learnt all the main techniques on my very first car. I spend a lot of time detailing my current car, and trying to keep my family's cars looking presentable too!

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