- Larger model capable of cutting up to 1.24-acre lawns
- Double-sided blade reduces wear
- Determines lawn pattern using an algorithm to ensure full coverage
- Durable device from a trusted brand
- Base model starts at $1,499.99 and the larger model is $2,899.99
- Maximum slope is just 22-24 degrees
- LTE connectivity is available, but at a significant cost
When it comes to outdoor power equipment, few brands are more recognizable than Stihl. Since the 1920s, this German manufacturer has been making tools that both professional and amateur landscapers depend on, such as chainsaws, blowers, brushcutters, and more. Today, thanks to its iMOW line, Stihl is now offering robotic lawn mowers.
Since robot lawn mowers are still relatively new to today’s market, it’s difficult to tell which brand is the best. Given its reputation, it would make sense that the Stihl iMOW is a top choice. But before you go out and spend your hard-earned money on a Stihl automatic lawn mower, read our full review.
The first thing you need to know about the Stihl iMOW mower robot is that there are actually four different models. They are:
- Stihl iMOW RMI 422 P
- RMI 422 PC-L Connected iMOW
- Stihl iMOW RMI 632 P
- RMI 632 PC-L Connected iMOW
Each model has a slightly different set of features and specifications. But before we discuss the unique qualities of each one, here are some of the things they all have:
- Automated mowing — You can preset the mower to your specifications, and it will do everything else on its own.
- .8” – 2.4” cutting height — Choose how long you want your grass to be, so long as it is within this range.
- Automatic charging — The mower can tell when it’s running out of battery and will return to the charging station on its own so that you don’t have to worry about it getting stranded in the yard.
- Algorithmic mowing pattern — The Stihl iMOW uses a complex algorithm to determine the best route for mowing your lawn that ensures maximum efficiency. At first, the path it takes may seem random, but it’s not. It’s designed to cut your grass in as short of a time as possible.
- Weather-resistant — Robotic lawn mowers by Stihl are designed to operate in any conditions, so you don’t need to worry about it getting destroyed by rain.
- Daily operation — These mowers are not always capable of mowing your entire lawn at the same time. They often have to return for charging. But they will do all of this on their own, meaning that your lawn will be evenly cut each week without you having to lift a finger.
Here is a breakdown of each of these four models and all of their specific features:
Stihl iMOW RMI 422 P
This is the most basic Stihl robotic lawn mower. It has all of the features listed above, as well as the following specifications:
- Maximum mowing area: .25 acre
- Maximum slope : 22 degrees
- Weight: 19.8 pounds
- 60 Watt motor
RMI 422 PC-L Connected iMOW
The next model up from the RMI 422 P is the RMI 422 PC-L Connected iMOW. It includes many of the same features as the RMI 422 P except that it has a slightly larger maximum mowing area. Instead of .25 acre, the RMI 422 PC-L Connected iMOW can cover up to .42 acres.
Part of the reason this model can cover more area without a more powerful battery is because it also comes equipped with LTE connectivity, the same type of wireless internet service you get on your phone.
This allows it to use GPS to draw a more accurate map of your lawn and come up with an even more efficient mowing pattern.
In addition, this connectivity allows you to take advantage of a whole host of other features. For example, the mower can get weather reports and hold off on mowing while it is raining. Yes, the mower can operate in any conditions, but wet grass is harder to cut and will reduce overall mowing time. And because it’s connected to the internet, you can also remotely control the mower through the Stihl app.
The app will also provide information about device maintenance, alerting you when it’s time to update software, sharpen the blade, adjust the perimeter, and more.
However, all of these extra features come at a cost. Whereas the RMI 422 P costs $1499.99, the RMI 422 PC-L Connected iMOW costs $1,899.99, which is a $400 difference.
Stihl iMOW RMI 632 P
The next version of the iMOW robotic lawn mower is the 632 P. It’s almost the exact same thing as 422 P, but the main difference is that it has a much bigger motor and battery. Specifically, it has a 185 Watt motor, which is more than double the power on the 422 P model.
This translates to a much wider mowing area. In fact, with a maximum mowing area of 1 acre, it can mow up to four times as much grass.
The battery is one reason the 632 P can do this. But it’s also because of the hood sensor. A feature not available on the 432 models, this allows the robot lawn mower to work around built-in lawn features, make a better map, and cover more area.
The other major difference is that it can handle slightly steeper slopes. Instead of maxing out at 22 degrees, it can climb hills of up to 24 degrees. This is a small improvement, but for those with hillier lawns, it can make all the difference.
All of this extra performance means the RMI 632 P is heavier (28.6 pounds as compared to 19.8 pounds), and also more expensive. This Stihl robotic lawn mower retails for $2,199.99
If you like what you see here but are having trouble finding the iMOW in the U.S., there are other 1-acre yard mowers to consider.
RMI 632 PC-L Connected iMOW
As was the case with the 422 P and 422 PC-L models, the only real difference between the 632 P and 632 PC-L models are connectivity and mowing area.
By using AT&T LTE service, the RMI 632 PC-L Connected iMOW can create an even better mowing pattern that allows it to expand its maximum mowing area to 1.24 acres. It will also provide you with maintenance information, as well as other important updates that will allow you to get the most out of your device.
However, once again, this added performance comes at a cost. The RMI 632 PC-L Connected iMOW will run you $2,899.99, making it one of the most expensive robot lawn mowers you can possibly buy. For comparison, the most decked out version of the popular Garena SILENO comes with less than half of the price tag.
A Note About Installation
One thing we should point out is that all of these price tags do not include installation. For your Stihl lawn mower robot to work, you need to place guide wires around your property. These set up a boundary for the device, which will sense automatically, to ensure it mows your entire lawn and also doesn’t wander off to your neighbors’ houses.
In theory, you can do this on your own. But Stihl recommends you let them do it, as most people won’t know how to do it correctly, something that can reduce efficiency.
Stihl charges $700 for installation, so if you go this route, you will need to add this to the price of the actual mower. This might seem steep, but since it will allow the mower to work better and more efficiently, it’s certainly worth considering. But it does raise the overall cost of a Stihl mower robot.
Should You Buy a Stilh iMow?
In terms of quality, it will be hard to find something better than the range of robotic lawn mowers by Stihl. As a long-time manufacturer of outdoor power equipment, they make stuff that works and won’t break.
In addition, Stihl lawn mower robots can do a few things that other models on the market cannot. For example, the maximum mowing area of the RMI 632 PC-L Connected iMOW is the largest on the market, making it pretty much the only choice for those who have larger lawns.
The two biggest reasons why you shouldn’t buy an iMOW robotic mower are maximum slope and price.
With a maximum slope of just 24 degrees on the more expensive model, the iMOW lags behind a lot of the competition, especially at this price point. Some mowers, like the Husqvarna Automower® 430X, are capable of handling slopes up to 45 degrees. Therefore, if you have a lawn with lots of steep grades, the Stihl iMOW isn’t going to work.
And then there’s the price. The RMI 632 PC-L Connected iMOW is one of the more expensive options you can buy. But it does come loaded with features you can’t find elsewhere.
However, the 422 P and the 632 P are both priced in similar ranges as their competitors. And considering the quality of Stihl products, it’s probably worth it.
Most robot lawn mowers cost more than $1,000. So, if you’re going to spend that kind of money, there is logic to spending a bit extra to get something high performing and that’s built right.
In the end, it’s your decision. If you are okay with spending a bit of money and don’t have a steep lawn, then the Stihl iMOW is one of the best products out there and is definitely worth adding to your outdoor tool arsenal.