STIHL Robot Lawn Mower Review

As of summer 2020, STIHL offers two models of its robot lawnmower: Stihl iMow RMI 422 P and Stihl iMow RMI 632 P. Here’s how both models rate with robot lawnmower experts.


Both STIHL robotic lawnmowers are loaded with sensors that alert users to operating issues like overheating or loose wires. When the machine comes close to a stationary object or it a user accidentally moves it out of position, the machine lets the user know the time has arrived to make a swift operating adjustment. For especially dangerous situations, the machine automatically shuts off its blades.


Although the STIHL line of robot lawn mowers does not include a GPS tracking device to determine the machine’s moving path, a PIN system integrated into the hardware of the law mower allows you to prevent theft. Punch n the security pin before starting the mower to access the security menu. Additional security features include mowing evenly across all types of terrain and not kicking out potentially harmful debris and allergens.

Two Stihl Robot Mower Models: Two Different Perimeter Settings

Selecting which of the two STIHL robot lawn mower models to buy depends largely on the size of your property. The RMI 422 covers up to one-quarter of an acre, while the RMI 632 covers one acre every time it is programmed to cut grass. STIHL differentiates the cutting capacities of both models by designing different brushless motors, as well as installing batteries that generate different amounts of energy.

When the Mower is Active

You decide when you want the STIHL robot lawnmower to start by setting a timing mechanism to go off at a specific time. The automatic start mechanism gives you the flexibility to cut the grass when you are at work or when you are enjoying a relaxing dinner at your favorite restaurant. During the time the automatic lawnmower moves across your property, your next-door neighbors should not even know the machine is on. The super-quiet lawnmower allows you to cut grass after the sun sets. When it rains, both STIHL robotic lawnmowers push through wet grass like a knife cuts through warm butter.

Manufacturer Support

STIHL receives rave reviews from customers for providing prompt and knowledgeable product and service support. Real-time customer support via the STIHL support page should take care of any operating issues, as well as give you quick access to the extensive inventory of STIHL spare parts. STIHL customer support personnel also help customers understand the complex algorithm that defines the operation of the automatic lawnmower. In addition, you can add an edging features that clean up the trim left behind after a lawn cutting job.


We did not mention price as one of the contributing factors for buying an automatic lawnmower. You can expect to invest in a product that can run into the thousands of dollars. The RMI 422 averages $1,300, while the RMI 632 touches $2,000. However, both prices fall below the average price for models that possess similar operating capabilities. 

stihl imow robot mower

Do not forget to add the cost on installation, which can boost the price of your new STIHL robot lawnmower by $700. A STIHL customer service representative can help you install your new machine, but you should consider asking your local lawnmower dealer to handle the installation process for you.

Specifications for Both STIHL Robot Lawn Mowers

Stihl iMow RMI 422 P

  • Motor: 60-watt brushless action
  • Power Source: 18.5V Li-ion battery
  • Battery Capacity: 80 W
  • Estimated Runtime: One hour
  • Weight: 19.8 pounds
  • Cutting Height: 0.79″-2.4″
  • Maximum Maintenance Area: 1/4-acre
  • Maximum Slope: 22º
  • Docking Station Cord Length: 32 ft
  • Price: $1299.95 plus $700 installation fee

Stihl iMow RMI 632 P

  • Motor: 185-watt brushless action
  • Power Source: 29V Li-ion battery
  • Battery Capacity: 194 W
  • Estimated Runtime: Two and a half hours
  • Weight: 28.6 pounds
  • Cutting Height: 0.79″-2.4″
  • Maximum Maintenance Area: 1 acre
  • Maximum Slope: 24º
  • Docking Station Cord Length: 32 ft
  • Price: $1999.95 plus $700 installation fee

The Bottom Line

As one of the leading manual lawn mower manufacturers for decades, STIHL has emerged as the leader for manufacturing high-quality automatic lawnmowers. The company’s two robot lawn mowers deliver precision cutting that makes manually operating a lawnmower a distant memory. 

Dependable security features ensure the robotic lawn mowers remain on course to complete a grass cutting job in a timely manner. Safety features prevent the machines from hurting anyone that programs them, as well as unexpected visitors to your property. 

Above all, both the RMI 422 and RMI 632 models have lifespans that last for years to come.

Robot Mower Buying Factors

The most important factor to consider before you pull out a credit card to make a purchase is the size of your property. Lawn size and the grass cutting capability of an automatic lawnmower must match. For example, if you need to cut a lawn measuring one-half of an acre, the robotic lawn mower you should consider must be able to handle close to 22,000 square feet. If you need a robot mower to cut a large lawn, one acre or more, make sure it can handle 43,500 square feet or more.

Here are the other buying factors to consider:

  • Safety
  • Security
  • Perimeter setting
  • Battery life
  • Automatic start
  • Low noise level
  • Object detection
  • Manufacturer support

Perimeter setting is a feature that ensures your new robot lawn mower more never strays from your property. Manufacturer support includes easy access to spare parts. Despite owning a quality automatic lawnmower constructed by a highly rated manufacturer such as STIHL, you eventually need to order spare parts to keep the machine working at peak efficiency.

2 thoughts on “STIHL Robot Lawn Mower Review”

  1. I recently had a Stihl iMow 632 P installed. The mower works very well, the paper manual that came with it is for someone familiar with the mowers operation, not a newbie. Changing mowing times shouldn’t be that problematic.

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