Karcher K3 vs K4: Which Pressure Washer is Best?


The range of Karcher pressure washers can be a little confusing making it difficult to decide which model is the best for your needs. Two very similar and popular pressure washers are the K3 and K4.

In this article, I’ll be directly comparing these two Karcher pressure washers in terms of their performance and key features so you can decide which is the best option.

Karcher K3 vs K4

The Karcher K4 is more powerful and expensive than the Karcher K3. The K4 has a maximum flow rate of 420 L/hour and 130 bar pressure whereas the K3 has a maximum flow rate of 380 L/hour and 120 bar pressure. The K4 is also heavier and larger than the K3.

FeatureKarcher K3Karcher K4
Max Flow Rate380 L/ hour420 L/ hour
Max Pressure120 bar130 bar
Area Performance25 m2/ hour30 m2/ hour
Power Rating1600 W1800 W
Hose LengthCompact version is 6 meters, Power Control version is 7 metersCompact version is 6 meters, Power Control version is 8 meters
Compact Version Weight4.2 kg4.7 kg
Power Control Version Weight4.4 kg11.5 kg
MotorAir-Cooled on all versionsAir-Cooled on Compact version, Water-Cooled on Power Control version

Images link to Amazon

Karcher K3 Compact

Karcher K4 Compact

Karcher K3 Power Control

Karcher K4 Power Control

Performance

There are two aspects to consider here:

  • Pressure
  • Flow rate

The Karcher K4 is a more expensive model compared to the K3 and hence offers an improvement in performance due to its greater maximum pressure and flow rate.

  • Karcher K3 models have a maximum flow rate of 380 L/ hour whereas K4 models have a maximum flow rate of 420 L/ hour.
  • Karcher K3 model s have a 120 bar maximum pressure whereas K4 models have a 130 bar maximum pressure.

Hence, the K4 offers an 11% increase in flow rate and an 8% maximum pressure increase.

Both models are capable of cleaning cars, outdoor furniture and patio flags though and the pressure difference isn’t huge in reality.

If you are washing your car and using a snow foam cannon, you’ll find that the K4 helps to create thicker snow foam. Although, you’ll still be able to get very good snow foam from a K3 if you pair it with a good quality foam cannon.

Size and Weight

There are several versions of both the K3 and K4 pressure washer. The K3 has 3 variants: compact, home and power control. The K4 has 2 variants: compact and power control.

The K4 versions are heavier and larger than the K3 versions. The “compact” variants are of course smaller and lighter to help save space when storing.

Here are some tables to show the different dimensions and weights of each pressure washer.

Metric Units

Karcher ModelLengthWidthHeightWeight
K3 Compact26.4 cm25.6 cm45.0 cm4.2 kg
K3 Home27.5 cm27.9 cm80.2 cm6.5 kg
K3 Power Control29.7 cm29.0 cm67.7 cm4.4 kg
K4 Compact27.3 cm25.6 cm45.7 cm4.7 kg
K4 Power Control40.2 cm30.6 cm58.8 cm11.5 kg
Karcher K3 and K4 Series Pressure Washer Dimensions (Metric Units)

Imperial Units

Karcher ModelLengthWidthHeightWeight
K3 Compact10.4″10.1″17.7″9.3 lbs
K3 Home10.8″11.0″31.6″14.3 lbs
K3 Power Control11.7″11.4″26.7″9.7 lbs
K4 Compact10.7”10.1”18.0”10.4 lbs
K4 Power Control15.8”12.0”23.1”25.4 lbs
Karcher K3 and K4 Series Pressure Washer Dimensions (Imperial Units)

Other Key Differences

There are also a few other differences between the K3 and K4 worth mentioning:

  • The K3 Compact, K3 Home and K4 Compact all have 6 meter hoses. The K3 Power Control has a 7 meter hose and the K4 Power Control has an 8 meter hose.
  • All K3 models and the K4 Compact have air-cooled motors. The K4 Power Control has a water-cooled motor which is designed to be more durable.
  • The K4 has a higher power rating of 1800W compared to the K3 which has a rating of 1600W so the K4 will use slightly more electricity.

Model Variants (Power Control, Compact, Home etc.)

There are several different versions of both the K3 and K4 pressure washer. Karcher use the “K-number” to group models the series according to the flow rate, pressure and power rating. However the different variants are separated according to the accessories and some specification differences.

K3 Variants

  • K3 Compact
  • K3 Home
  • K3 Compact Home
  • K3 Power Control
  • K3 Premium Power Control

All these models have the same power rating, maximum pressure rating, flow rate and an air-cooled motor. Here is a table highlighting the differences between them.

FeatureK3 CompactK3 Compact HomeK3 HomeK3 Power ControlK3 Premium Power Control
Hose Length6 meters6 meters6 meters7 meters7 meters
Weight (without accessories)4.2 kg4.2 kg6.5 kg4.4 kg5.6 kg
Dimensions (L x W x H)26.4 x 25.6 x 45.0 cm26.4 x 25.6 x 45.0 cm27.5 x 27.9 x 80.2 cm29.7 x 28.0 x 67.7 cm34.0 x 28.1 x 67.7 cm
Detergent ApplicationSuctionSuctionTankTankTank
Telescopic HandleYesYesNoYesYes
Integrated Hose ReelNoNoNoNoYes
LED Trigger DisplayNoNoNoYesYes
Accessories IncludedVario Lance Dirt BlasterVario Lance Dirt Blaster
Patio Cleaner
Vario Lance Dirt Blaster Patio CleanerVario Lance Dirt BlasterVario Lance Dirt Blaster Patio Cleaner

K4 Variants

  • K4 Compact
  • K4 Power Control
  • K4 Power Control Home
  • K4 Power Control Car & Home
  • K4 Premium Power Control Car & Home

All K4 models have the same power and pressure ratings, and flow rates. Here is a table highlighting the differences between them.

FeatureK4 CompactK4 Power ControlK4 Power Control HomeK4 Power Control Car & HomeK4 Premium Power Control Car & Home
Hose Length6 meters8 meters8 meters8 meters8 meters
Weight (without accessories)4.7 kg11.5 kg11.5 kg11.5 kg12.0 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 cm41.4 x 30.6 x 58.8 cm
MotorAir-CooledWater-CooledWater-CooledWater-CooledWater-Cooled
Detergent ApplicationSuctionPlug and Clean SystemPlug and Clean SystemPlug and Clean SystemPlug and Clean System
LED Display on TriggerNoYesYesYesYes
Integrated Hose ReelNoYesYesYesYes
Accessories IncludedVario Lance Dirt BlasterVario Lance Dirt BlasterVario Lance Dirt Blaster Patio CleanerVario Lance Dirt Blaster Patio Cleaner Car Brush Foam Cannon Car ShampooVario Lance Dirt Blaster Patio Cleaner Car Brush Foam Cannon Car Shampoo

Accessory Kits

As you’ll have noticed from the tables above, some models come with a “home” or “car and home” kit which features some extra accessories.

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

The “rotating wash brush” will scratch the paintwork on the car and should never be used. You can also find much better foam cannons from other companies which are compatible with the Karcher models as well as better shampoos.

Check out my car cleaning product recommendations if you’re looking for some suggestions.

K3 and K4 Similarities

  • 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.

Full Specification List

FeatureK3 CompactK3 HomeK3 Power ControlK4 CompactK4 Power Control
Current Type220-240 V220-240 V220-240 V230-240 V230-240 V
Minimum Pressure20 bar20 bar20 bar20 bar20 bar
Maximum Pressure120 bar120 bar120 bar130 bar130 bar
Max Flow Rate380 L/ hour380 L/ hour380 L/ hour420 L/ hour420 L/ hour
Area Performance25 m2/ hour25 m2/ hour25 m2/ hour30 m2/ hour30 m2/ hour
Water Feed Max Temp40°C40°C40°C40°C40°C
Power Rating1600 W1600 W1600 W1800 W1800 W
Power Cable Length5 meters5 meters5 meters5 meters5 meters
Hose Length6 meters6 meters7 meters6 meters8 meters
Weight (without accessories)4.2 kg6.5 kg4.4 kg4.7 kg11.5 kg
Dimensions (L x W x H)26.4 x 25.6 x 45.0 cm27.5 x 27.9 x 80.2 cm29.7 x 28.0 x 67.7 cm 27.3 x 25.6 x 45.7 cm40.2 x 30.6 x 58.8 cm
MotorAir-CooledAir-CooledAir-CooledAir-CooledWater Cooled
Detergent ApplicationSuctionTankTankSuctionPlug and Clean System
LED Display on TriggerNoNoYesNoYes
Telescopic HandleYesNoYesYesYes
Karcher K3 vs K4 models

Still not sure which Karcher model to go for? Check out my complete guide to the Karcher Pressure Washer range for more information.

Here are some more articles you might find useful:

Heather

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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