Best rear-wheel drive mower

Self-propelled mowers are usually compared on runtime and deck width. The specification that changes how the machine behaves under load is neither of those: it is which wheels are driven, and these three are the mowers in our registry that publish the answer.

The short answer

What drive layout actually changes

A mower's weight shifts constantly. Push uphill and it transfers to the rear wheels. Fill a rear bag with wet clippings and it transfers to the rear wheels. Tip the handle down to pivot at the end of a pass and it transfers — again — to the rear wheels.

Traction follows weight. That is the entire case for rear-wheel drive: the driven wheels are the ones being loaded exactly when you need grip. Front-wheel drive lightens under the same conditions, which is when it starts scrabbling. What front-wheel drive buys in exchange is easy turning, because you can lift the front and pivot on the rear wheels without fighting the drive.

For the flat-lawn, no-bagger case, either works. For hills, for bagging, and for long grass that loads the deck, rear-wheel drive is the layout to look for — and it is published, so you can.

What the drive motor costs in watt-hours

Self-propulsion is not free. Take each manufacturer's published battery capacity and its published runtime claim, and the energy cost per minute falls out.

The three, on published figures

1. Kobalt 80V — most energy, most drive speeds

Two 80V 4.0Ah packs in a dual-port deck: 640 nameplate watt-hours, the largest in this group by a third, on a machine rated for up to an acre with seven drive speed settings and a 60 to 90 minute recharge.

Seven discrete speeds is a different philosophy from Toro's pressure-sensing drive. On a large lawn with long straight passes, setting a speed and walking it is less tiring than modulating pressure for forty minutes.

It is also the least efficient of the three on published claims, at 8.0Wh per minute, and Kobalt publishes no weight, no cut-height range and no storage detail. Dual-port machines also mean two packs to buy when they age.

#ad Check the Kobalt 80V Max 21" Self-Propelled (dual-port) price on Amazon — how we're funded.

2. Toro 21356 — best drive control

Personal Pace is the reason to choose this one: push a little harder and it speeds up, ease off and it slows. On a lawn full of beds, corners and obstacles, a drive that tracks your walking speed is genuinely less work than reaching for a lever.

Toro also publishes the numbers others do not: 324 watt-hours stated directly rather than left to nameplate arithmetic, a 150 minute charge time, 66 lb, a 14-gauge steel deck and SmartStow vertical storage — which is the difference between a mower that fits along a garage wall and one that does not.

The trade is capacity. Three hundred and twenty-four watt-hours is half the Kobalt, and the 45 minute claim is the shortest here. On a large lawn that is a second battery, not a preference.

#ad Check the Toro 60V Max 21" Recycler Self-Propel (21356) price on Amazon — how we're funded.

3. Ryobi RY40HPLM01B — the efficient one

Two 40V 6.0Ah packs, 480 nameplate watt-hours, a claimed 80 minutes, and a brushless motor with variable-speed rear-wheel drive. On the makers' own claims that is 6.0 watt-hours per minute — 25% less than the Kobalt for the same claimed runtime.

Forty-volt packs are also the most widely shared platform of the three, which matters if a trimmer and a blower are already in the garage on the same batteries.

What it does not publish: weight, cut-height range, charge time or a rated area. That is three unknowns in a category where the other two answer at least some of them.

#ad Check the Ryobi 40V HP Brushless 21" Self-Propelled price on Amazon — how we're funded.

Choosing between them

1. Slopes and bagging. All three are rear-wheel drive, so all three behave correctly under load. Weight and traction do the rest — see best mowers for hills.
2. Lawn size. Above about half an acre, capacity wins and the Kobalt's 640Wh is the argument. Below it, drive control matters more.
3. Existing platform. If your other tools are on 40V, the Ryobi costs you nothing extra in batteries.
4. Storage. Only Toro publishes a vertical storage feature, and only Toro publishes a weight to carry.

Who should skip all three

• Small flat lawns. A drive motor costs energy and money you do not need — see self-propelled vs push.
• Anyone who turns constantly. Rear-wheel drive resists the tip-and-pivot turn. On a lawn cut into small sections, front-wheel drive is genuinely easier.
• Very steep ground. No manufacturer here publishes a maximum slope, and a mower on a bank is a footing problem before it is a traction problem.

What we cannot tell you

We have not mowed with these machines. None of the three publishes a maximum slope, a drive wheel torque figure or the conditions its runtime claim was measured in. Kobalt and Ryobi publish no weight and no cut-height range. The energy-per-minute figures above are arithmetic on published claims from three different manufacturers using different voltage conventions, so treat the ranking as a comparison of claims rather than of measured performance.