In this post, I will look and compare Eufy 11s and Eufy 15c. One of them is Eufy 11S, which is probably one of the best-selling robot vacuum in the budget category. But Eufy has recently released the 15C max model, which is a little bit more expensive but still in the budget category.

The question is what are the differences between Eufy 11S and 15C max? And is it worth it to pay a little extra for the upgraded version?

Eufy 11S and Eufy 15C max have the same physical design, battery, airflow, and bin size. The suction power of 15C max is more than 11S but honestly it will make little to no difference without extra airflow. The major difference between both models is the Wi-fi capability. The use of the app probably justifies the price difference if it is within 30-40 dollars. 

We first compared all the specs of Eufy 11S and 15C max to see all the main differences. 

Note: You can check the specs table at the end of the post 

Eufy 15C MAX

Eufy 11S and Eufy 15C max comparison

While comparing the specs the first thing which pops out is that Eufy 15C is Wi-Fi capable. This means in addition to the included physical remote, you can also download the app with 15C max. So you could do all the things which you do with remote like schedule cleaning with the app. With the app you can do all the above things from anywhere in the world.

Another big difference is power. According to Eufy, the new 15C max has 2000 pascals of suction compared to 1300 pascals of suction in Eufy 11S.

We did confirm that 15C max has about 35% more suction than 11s in tests. But suction is just one of the important parameters to measure and determine power. The other parameter to determine the power is airflow. 

In the airflow test, both the models have the exact results. Both models have an airflow of 10 CFM in low power and 15 CFM in high power. This value of airflow is pretty good for their price and other budget robot vacuums. 

Crevice pickup test | Eufy 15C Max vs Eufy 11S

In the crevice pickup test, Eufy 15C max did much better than Eufy 11C. What was interesting for me was that I always thought important factors in these tests is airflow and a good seal.

But because these both models have near-identical construction and the same amount of airflow the only variable here is the suction power. And so it seems that suction is more important than the airflow in this test.

It is also important to note that other than the crevice pickup test, these robots seem to have the same performance. For example, on the carpet deep clean test, they got almost identical scores after running the test three times each.

The performance of 15C max was just a little bit below Eufy 11C performance in every test. In the deep clean test, 15C max scored 70% whereas 11C has a score of 75%.

So I guess agitation and airflow are more important than suction for deep cleaning carpet.

Navigation with Eufy 11S and Eufy 15C Max

In terms of navigation, both Eufy 11S and 15C max are the same. They both use more and less random algorithms to clean around your home. Both the models were very efficient in small room test. They almost gave 100% coverage in the 25-minute runtime.

Most Eufy robot vacuums have good programming about chair legs and other hard to reach places.

I will give both models, a good score on their coverage and navigation considering their price range.

Physical design

The physical design of both Eufy 11S and 15C max is similar. Not only these two robots share a similar physical design but in recent years many other companies are starting to copy a similar design. One of the reasons behind this is that this design is so successful for many years.

This extra-slim design at 2.85-inches is almost an inch shorter than the average robot vacuum. Extra-slim design is really good for getting under all kinds of furniture. But this also means that it will have some other drawbacks. For example, it is not good at climbing threshold and picking up larger debris.

Performance

Both of the models were excellent in the pickup test of normal size debris. In the test for picking up debris ranging from fine to normal size on the hard floor and the carpet, they both did well. 

But when it comes to larger debris of fruit loops size or more, both models were short in performance. They would typically end up picking up only 40% or less of the amount. These kinds of debris would get stuck underneath or pushed aside because of the extra low profile. 

In the carpet test, it performs a little bit better than the hard floor. This is not likely to be a big problem in most situations unless you have a lot of extraordinary size mess. 

Cons in Eufy 11S and Eufy 15C max

Since both the models have the same brush and brush housing, they share another con equally. Both models have a hair tangle situation but this problem is with most budget robot vacuums.

In comparison to other brands budget robot vacuums, Eufy 11S still gave impressive results in this test. With the one gram of 5-inch hairs, 40% of the hair got tangled in the brush. In the test with one grand of 7-inch hairs, 65% of the hair got tangled.

This result is not as great as compared to more expensive robots, but still better than models of their price range.

Battery 

Both Eufy 11S and Eufy 15C max has the same 2600 mAh battery. According to the manufacturer, both have the same 100 minutes of runtime on low power. On the high power, 11S has 50 minutes whereas 15C max has 40 minutes because of the more suction power. 

The suction power of 15C max is of 2000 pa and 11S is of 1300 pa. 

Both models have a third power setting mode which is boost IQ mode. Boost IQ mode is a setting that is low power and automatically boosts to high power when it senses carpet. 

Dustbin

Both Eufy 11S and Eufy 15C max has 600 milliliters of the dustbin. This size is bigger than most of the budget price robot vacuums.

Also, it empties well and it is very easy to clean.

Conclusion

So back to the original question is it worth the extra money to go for the Eufy 15C max over 11S?

I would say it depends if you can find the deal and the price difference is within 30 dollars or so on that particular day.

The prices seem to change all the time because of deals and offers and if you can find it then go for it. The only reason I am saying this is because of the Wi-Fi capability. With the app, you can control the robot when you are not at home. You can also get alerts on your phone when it gets stuck or something.

The extra suction is nice but with the same airflow power there is only limited use for that extra suction. The good thing about both models is their design and performance. There is the reason that they have been rated so highly over the years but they also have some limitations.

But generally speaking in budget range those limitations are in most of the other robots.

Specification of Eufy 11S and 15C

ModelEufy 11SEufy 15C Max
Bin size600 ml600 ml
Floor TypeCarpet & hard floorCarpet & hard floor
FilterHEPAStandard
Weight5.85 lb6 lb.
Height2.85 inches2.85 inches
Anti tangle rollerUnknownUnknown
Active Hair removalNoNo
Suction1300 Pa2000 Pa
Colorblack, whiteBlack
Warranty1 year1 year
Battery info2600 mAh2600 mAh
Battery life100 min100 min
Wifi enabledNoYes
Charging time5-6 hours5-6 hours
Alexa google enabledNoYes
Mop attachmentNoNo
Smartphone AppNoYes
Navigation TypeRandomRandom
Processor SizeunknownUnknown
Side Edge Brush22
Interchangable IntakeNoNo
Auto RechargeYesYes
Carpet BoostYesYes
Dirt detect sensorNoNo
Anti cliff sensorYesYes
Auto empty binNoNo
Max climbing height.63 inches.63 inches
Remote controlYesYes
Physical Barriers includedNoNo
Artificial InteligenceNoNo
No-go zonesNoNo
Multi-floor mappingNoNo