Stihl RMA 448V review: Stihl’s self-propelled super-mower is the best thing for big lawns

Keeping one or more massive lawns well trimmed can be a lot of hard work, but not if you’re using a mower like the Stihl RMA 448V. Designed for lawns of up to 340m² in size, it combines a powerful but lightweight motor with a 46cm cutting width and has its own drive to push itself forwards at speeds of up to 4.5km/h. Not only will you get your lawn mowed in fewer passes, but you’ll have to put less effort in to complete each one.

Be warned: this is a big, heavy mower that requires a lot of space to store compared to other, more average-sized lawn mowers. It also costs substantially more than smaller rivals. But if you’ve got a larger lawn and want to get the job done faster, you won’t find many that work as well as this.

Stihl RMA 448V review: What do you get for the money?

A large, self-propelled cordless mower with a generous 46cm cutting width, the Stihl RMA 448V is a beefy and costly mower at £599. You’ve actually got four different ways to handle pesky grass clippings, with Stihl bundling in a 52l grass collection box, but also providing an integrated mulching plug and a flap that fires out clippings sideways. Alternatively, you can simply remove the box and let the clippings drop out from the back as you mow.

The deck rises up and down when you move a lever in the top handle, giving you a choice of cutting heights between 20mm and 100mm. The heavy-duty polymer and metal shell feels incredibly robust, while every mechanism works easily and smoothly. This is a beautifully engineered mower, and its single-stalk handle lends it an extra touch of cool. You’d almost be tempted to push it casually one-handed, though it’s probably smarter and safer to use two.

The RMA 448V uses up to two of Stihl’s 36V AK series batteries for power but is sold solo or with a single AK30 battery and charger for an extra £150. Sold separately, the charger costs approximately £44, with batteries at £60 to £150.

Stihl RMA 448V review: How easy is it to use?

The RMA 448V is actually quite compact by the standards of professional cordless and petrol mowers, but still pretty large by the standards of consumer cordless mowers. It’s 52cm wide and 1.5m long with the collector box attached and it stands 108cm tall. There is a mechanism to fold the handle down over the body of the mower, reducing the length to 92cm for storage, but at 27kg in weight it’s not the kind of mower you’ll want to carry around more than you have to.

On the lawn, though, it feels much lighter and easier to push around, even without the self-drive motor engaged. You can slot up to two batteries into the compartments provided under the white cover on the top, where you’ll also find the main power switch. After that’s turned on, you just need to press the start button on the right-hand side of the main handle, squeeze the rear bar in to start the motor and then the front bar to start the forward drive. A level on the handle switches between drive off and the five available speeds, which take you up from 2 to 4km/h.

There’s a slight delay between squeezing the drive lever and the mower trundling forwards, but once it’s moving, it will keep going fairly straight until you release the lever. Turning at the end of each row takes a little practice, but you can always reduce the speed or just pause forward motion while you manoeuvre the mower into place for the next run. The action of the wheels is impressively smooth, tackling bumps and undulations without any problems. I found the forward drive incredibly useful when mowing upwards on a slope. With no effort needed to push the mower, I could concentrate on the steering.

Stihl RMA 448V review: How well does it mow?

In a word, flawlessly. The RMA 448V delivered a spectacularly neat short crop on my front lawn, leaving it looking almost manicured. There’s no rear roller on this particular model, but it’s one of the tidiest cuts I’ve ever seen here. And on the back lawn, where the grass can be thicker and wilder, Stihl’s mower tackled everything with ease, even making the best of rough and still weed-strewn patches I’d recently strimmed in preparation. There’s a lot of mowing power here and the upshot of this is that it will slice through nearly anything you put in front of it.

It’s not too noisy when it’s running, either. I measured outputs of 73 to 79dB while in use, which isn’t bad by the standards of some smaller cordless mowers, let alone petrol-powered models, which are usually good for 10 to 15dB more. While the 24 minutes of battery life I had from a single AK30 battery isn’t what you might call epic, the second slot gives you the option to effectively double it. The second battery takes over automatically as soon as the first is spent. The battery took just over 3hrs 20mins to charge using the bundled AL101 charger, though it will charge to 80% in roughly forty minutes less.

Stihl RMA 448V review: Should I buy it?

If I had a large garden with expansive lawns to mow I’d take a good look at the RMA 448V. Even on a long flat lawn it’s going to reduce the effort involved and it gives you the capabilities of a professional lawn mower with a lower size, weight and cost.

Those with small to mid-sized gardens have smaller and cheaper options available, check out our best small lawn mower page for those, but this is the best mower for massive gardens that I’ve tested. It’s also surprisingly good value once you see what you’re getting for your money.