Karcher K7 Compact - Lets test real PSI and Flow and see if they are lying?

Come with me on this little adventure where we test real world PSI, Flow, Amps and Wattage that are on the spec plate and learn a few things along the way. As usual comment below , like and subscribe if you want to see more content like this. This video is not sponsored and I don't get any kickbacks for the below links but this is where I bough my stuff in the video from

[ronniecrop]

To answer your question about pressure ratings. A lot of company dont list the operating pressure, they list the overflow valve (or unloader valve depending on your country) opening pressure. Simply put, the operating pressure is whats reached when the trigger is pulled. So the pressure created by the nozzle as a fixed amount of volume runs through it. The overflow valve opening pressure (sometimes called spike pressure) is the pressure that needs to be reached for the machine to go in to bypass mode. So in the end overflow valve opening pressure is ALWAYS greater (10-20%) than operating pressure. So of course the marketing department uses opening pressure in the literature and nomenclature.

[andyc]

Great test. Am looking at buying the compact one to replace my old kartcher. Will now. Keep up the great work.

[ha]

Thanks Sam, great video. Also thanks for the explanations in the comments. Some of the points I didn’t fully understand first time watching. Just wondering, how long did it take to wash your driveway? Would you say it is faster than your previous machine?

[matheusassis]

Thanks for the video. It's exactly what I was looking for.

[Waza-kz]

Thanks, great video. I have always been a bit disappointed with my K7 Compact. The specs advertised just don't seem to meet my real world experience. I find the machine a) very noisy and b) much lower on water flow than the specs suggest. From my measurements, I don't get anywhere near the advertised 8.2l/m. I bought the machine primarily for car washing and as a general purpose cleaner (driveway, pool, windows, house, gutters etc). Water flow was one of the key criteria and on paper the K7 Compact spec'd well. However in practice, I just don't think it stacks up against similar priced machines like the Bigbio Washr Pro or the AR680. And don't get me started on that hose and lance! You know what I mean. Here are my real world measurements. Please note these are my measurements taken with my setup, yours may differ.

I have my machine set up with a 50ft 1/4" Uberflex hose running 3/8 quick connects into an MJJC short trigger gun (27 l/m). My garden hose is a standard 12mm x15m hose. Water flow out of hose is well above 20 l/m and with enough pressure that sealing it off with my thumb is difficult

- 4.0 (25 deg, green) nozzle - 6.66 l/m @800psi
- 3.5 (25 deg, green) nozzle - 6.60 l/m @1, 000psi
- 3.0 (25 deg, green) nozzle - 6.35 l/m @1, 250psi
- 2.5 (25 deg, green) nozzle - 6.05 l/m @1, 750psi

Note, all pressure measurements were taken at the input to the trigger gun. I am losing roughly around 80psi through the hose so the pressure that the machine output will be slightly higher than I have listed.

While these number are not terrible and the machine does the intended job ok, I just cannot seem to get anywhere near the advertised max waterflow with my setup. Maybe I am doing something wrong, and yes, I know, I have not measured the water flow with the genuine Karcher hose/lance so that may well have an impact on waterflow results. However, in my opinion, these numbers don't seem all that different to much cheaper machines with similar setups reviewed by many car detailing channels. This is the main reason why I am disappointed with my K7 Compact.

Anyway that is my experience, yours may be very different. Personally, and from what I now know about pressure washers, I will look elsewhere next time around.

[erichokahang]

Thank you for your excellent test, reply from Hong Kong.

[hunnagazunna]

Cheers mate. Very informative Sam. But have I missed the point here? Correct me if I'm wrong but your PSI measurement came out to only around 1800PSI using the Karcher lance and a little higher using the Audi one. Both nowhere near the claimed 2500 PSI. And isn't ultimately the PSI reading the real measure of how powerful the device is at removing dirt? Many thanks in anticipation of an explanation as I'm minded to get one of these otherwise.

[usmanafzal]

Thanks for the great video, but could you tell the orifice size for the red nozzle.😅

[rooboy]

Just purchased a k5 compact. My testing got 6.4 lpm. Minimum flow in specs is 7.5 to 8.3 max. So mine is about 15% under minimum flow rate. Also, you didnt subtrsct bucket weight from the 8.1kg of water. My 15L bucket weighs 650gms. So if yours is similar you got around 7.5 kg or 7.5 lpm

[TheTomasiukas]

Thanks for your yob! Great test. Can you share link to inline pressure gauge adapter? I can't find it.

[Milele]

Well done mate from Melbourne! You got me going for it!

[lve]

Can you do one using the machine on diff surfaces or cleaning different parts

[jamiefor]

Looks like you didn't take away the weight of the bucket.

[RIDER_GT]

Good test! Thaks!
I have the same model. Bought just yesterday. But my pressure washer consumes 3 kW of energy. And it actually has a minimum pressure of 150 bar compared to your pressure washer. Interesting...This iformation i saw on the back side.

[airzone]

Thanks for this. Going to grab one now.

[Iby]

But one downside of the Karcher is the metal alloys they use instead of the brass parts like some of the better quality units, Kranzle (german made and had some unfortunate inflation issues over the last few years) have brass parts and people like the longevity they have

[banchang]

Does this mean it doesn't get the advertised 2600 psi ?

[jamest]

Get the gauge checked/calibrated.. cheap gauges can be out by over 50% and change in accuracy depending on pressure… and don’t believe the ‘calibration’ cert provided 👍

Talking as someone who works in a laboratory with pressure testing equipment to NATA and AS standards.

[AdrianAmoroso]

Thanks for the video - nice to validate their specs. Just wondering your take on it... is the lance that comes with it that bad? Do you think it should be replaced to make the unit worthwhile? Thanks!

[EltunBabayev]

On the box written 2600 psi. But barometer didn't show that value. Why?