The best petrol mower is likely to be much more powerful than any electric model, and for people with lots of lawn to mow they are also more convenient: no cable means you can go much further.
Petrol mowers are generally very reliable, they’re excellent for long grass, they’re easier to get up hills thanks to the motor assistance, and the noise they make is fun if you're a petrolhead, too.
If you have a typical inner city lawn or a small suburban plot then a petrol lawn mower is clearly not going to be your ideal choice, and you'll be better served with a cordless model. However, cordless lawn mowers are not designed for very large lawns because they run out of charge too quickly. That’s where the good old-fashioned petrol option comes in.
With a petrol-powered mower you can mow and mow for hours on end – or as long as you have a can of unleaded petrol or Aspen 4 alkylate fuel to hand. Most petrol mowers are relatively easy to use and some even come with self-propulsion to make life even easier; simply engage the gear and walk behind it, holding on of course lest it develops a mind of its own and heads towards the swimming pool. Most petrol mowers are also more than powerful enough to tackle even the kind of long damp grass that might flummox a cordless or electric model.
There are some downsides, though. Petrol mowers are noisy, smelly and heavy, and you usually have to change the oil after the first 20 hours of use and after every successive season. You will also need to clean the air filter and change the spark plug from time to time. Oh, and you’ll need to fill it with unleaded petrol and not leave the fuel lying around in storage for more than a couple of months or it will go off (see below). So there's lots to do, then, before you’ve even hit the sod.
Just as we've done in our best robot lawn mowers, best strimmers and best chainsaws buying guides, we've filled our best petrol lawn mowers buying guide with a variety of models that offer different features and price points. This will make it easier to narrow down a unit that is right for your needs.
The best petrol mowers on sale in 2022
If you have a large lawn, consider the self-propelled Cobra MX534SPH, which comes fitted with a reliable 167cc 4-stroke Honda GCVX170 engine that is easily started in a standing position by using the cord conveniently attached to one side of the handlebar. Like all mowers, there is some assembly involved and the trickiest part is fitting the two cable nipples. Hint: unclip the power and propulsion bars first and then fit the nipples. I learned that the hard way. To start it all up, fill it with lawnmower-specific 4-stroke engine oil and just under a litre of unleaded fuel – or better still Aspen 4 – and start mowing.
The Cobra MX534SPH’s four-speed self-propulsion system is a joy to use even if the gear stick is a bit clunky. Just select your preferred walking pace – from a slow amble (2.5kph) to a brisk stroll (3.9kph) – and let the mower do all the hard work for you. You won’t even need to visit the compost heap all that often with this model because the blade’s integrated suction system literally flings the grass clippings way back into the huge 65-litre grass collector, compressing them in the process.
This mower comes with a 52cm cutting deck so it’s a perfect size for large lawns up to and well beyond 700m2. The large lever on its rightful, meanwhile, provides six stages of cutting height, from a low 25mm to 75mm. The Cobra performs supremely well, cutting grass really effectively no matter how long or damp it is. It also leaves a really neat and tidy finish in its wake.
Yes, the engine is pretty loud but it’s so reliable and so immensely powerful that noise levels sink into insignificance. Furthermore, this model lets you mow in three ways: conventionally using the 65-litre grass collector; downwards mulching where fine grass cuttings are forced back on to the lawn; and sideways mulching where the cuttings are thrown out of the side using the included chute. When you’re done mowing for the day, simply attach a hose to the fitting on the top of the chassis, turn on the tap, start the engine and the deck is given a good water thrashing.
Petrol mowers are usually the best option for homes in the countryside where noise isn’t as much of an issue. In this regard, the Cobra MX534SPH is a terrific contender that should provide years of reliable cutting with very little effort.
We think this large decked mower is the best for most people, but to see if you'd be better off with a different system, be sure to check out T3's Cobra MX534SPH vs Honda HRG 416 PK comparison feature.
This is one of the best-value self-propelled mowers we’ve come across. Powered by a 99cc Einhell single-cylinder 4-stroke OHV engine that is surprisingly quiet for a petrol mower, this Germanic lawn slayer impressed with its cutting skill and exceptional manoeuvrability. Granted, the self propulsion speed is fixed at a spritely pace but as long as you’re even moderately fit, it shouldn’t be an issue.
The Einhell comes with a 40cm deck (suitable for lawns up to around 300m2), a 45-litre grass catcher and a cutting height range of 25-60mm in seven increments. Assembly and set up was a doddle and, after pumping the fuel feed, it started on the second pull. At a smidge over 21 kilos it isn’t ridiculously heavy either. If you want or need self propulsion but can’t afford an expensive cordless version, then this one’s well worth a punt.
Such is Honda’s excellent reliability record in all things engine related, we’re guessing this mower’s powerful pull cord-operated 160cc OHC 4-stroke will go on performing till the cows come home – or at least until the next blue moon. Your neighbours will like it too because its noise level is allegedly 30% below the current EU standard.
The HRG 416 is equipped with a 0.91-litre unleaded fuel tank for lengthy sessions in the rough while its 41cm steel cutting deck and 50-litre grass collector are of a decent enough size to handle half a tennis court’s worth of sward without having to make too many trips to the compost heap. Its cutting height range is marginally better than some others in this roundup (20mm to 74mm) so perhaps contemplate this model if you have different lawns made up of both long and short grasses.
This mower doesn’t have self-propulsion so you’ll just have to put some back into it. However, at 29kgs, it’s not overly heavy to handle. Overall, we prefer the similarly-priced Cobra mower reviewed above, mostly because it has multi-speed self propulsion and is capable of mulching. But this is still an excellent alternative.
If you have a lawn of around 40m x 40m and can’t be bothered with pulling on a cord to start your engine, have a gander at this well-specced model from UK brand Mountfield.
There's no huffing and puffing with this high-end model because it features electric key start; just fit the supplied lithium starting battery, push the start button and the 166cc Mountfield 4-stroke ST170 OHV engine fires up in an instant.
This model is equipped with a 46cm cutting deck, a large 60-litre grass collector with indicator to show it’s full, an especially wide range of cutting height positions (from 22mm to 80mm) and, as you’d hope for a mower that weighs a fairly hefty 27 kilograms, single-speed self propulsion (a suitably stately 2.23mph) for effortless navigation through the apple grove. It also comes with a mulching plug for those who prefer to have the cuttings fertilise the lawn. Petrol mowing doesn’t come much easier than this.
Hayter is the brand of choice among many professional groundkeepers so if you have a huge showcase lawn of around 1,000 square metres that you wish to keep beautifully manicured, then this is the brand to put at the top of your shopping list. This professional-spec monster has many plus points, not least the fact that it mows a lawn to near perfection while its 190cc 4-stroke, air-cooled Briggs & Stratton 850E engine thunders on for ages on a single tank of unleaded. What’s more, because it’s so heavy (a whopping 59kg) and comes with a rear roller, it lays an elegant lawn stripe, too – just like the wicket at Lords.
The Harrier 56 PRO comes with a massive 56cm aluminium cutting deck, a cavernous 70-litre fabric grass bag and the wherewithal to propel itself via fixed-speed Autodrive system, so you can mow one-handed while sipping on a G&T. It's a perfect choice for bowling green style lawns because the cutting height goes down to just 13mm; way lower than the vast majority of lawnmowers.
At 59kgs, this mower is far too heavy for one person to lift so make sure you have an under-cover storage space that provides easy access. Mind, if you’re looking at a mower of these dimensions and professional specifications, chances are you will have a groundskeeper to do all the hefty work in the first place.
To see how this petrol mower stacks up against our number one choice, then take a read of T3's Cobra MX534SPH vs Hayter Harrier 56 Pro comparison feature.
This is the petrol mower to grab for large stretches of long unruly grass, overgrown verges and inclines of up to 45˚. Like a Flymo, the AirMow51 hovers on a cushion of air and pretty much scythes through anything, even straw-like grasses. It’s exceedingly good for mowing steep inclines because its floaty nature means you can simply sweep it from side to side. The included wheels, meanwhile, are especially handy for keeping it on track on difficult terrain and for moving the mower from one area to another. However, it only has three height settings (17mm and 25mm) and no grass collector so everything will be spewed back onto the turf.
The AirMow51 Pro is equipped with a huge 51cm (20”) ABS cutting deck and powered by a reliable pull-start, four-stroke Honda GCV160 engine that’s relatively quiet and unyieldingly powerful. If you have a relatively large swathe of elongated grass that needs a good seeing to, this red grass mobster will do the deed. After all, if it’s good enough for professional golf course maintenance staff, it’s good enough for you.
Will E10 unleaded fuel work in my petrol mower?
You may have noticed that all standard unleaded pump petrol in the UK and Europe has changed from E5 to E10. E stands for Ethanol and the numbers that follow are percentages of ethanol in any given measurement of petrol. Since ethanol is a renewable fuel, governments are keen to introduce higher ratios of it to help tackle climate change. E10 doesn’t affect the majority of cars on the road since most modern car engines are built to run quite happily on it. However, E10 fuel does affect most classic cars and some older petrol mowers.
The problem with ethanol is that it is hygroscopic, which means it attracts and absorbs moisture like a sponge. According to Mowers Online, ‘when you add fuel that contains ethanol to your fuel tank, any moisture in the air inside a fuel tank will mix with the ethanol in the fuel which eventually results in water and ethanol being sucked through into the fuel system causing components to deteriorate and engine starting/running problems. In conclusion, ethanol causes multiple problems for small petrol engines and you shouldn't leave it in the tank.’
If you’re concerned about your petrol mower’s ability to run on E10 fuel, your best course of action is to add a fuel additive or stabiliser every time you top up your fuel can. This won’t remove the ethanol but it will coat the engine’s internals with a protective barrier, helping it to run more smoothly. It will also increase the life of the petrol itself, whether it’s stored in the shed or in the mower’s tank.
Having learned the hard way, this writer would absolutely advise always adding an additive to the fuel because I too have suffered from a jittery, surging lawnmower engine after using fuel that’s well past its prime (believe it or not, after just two months of storage). An additive should help forecourt fuel last for up to three years.
But there is another fuel solution which I recently learned about from a reputable lawn mower engineer. It’s called Aspen and it’s available for both four-stroke and two-stroke engines. Aspen is an ethanol-free alkylate fuel that contains 99% fewer harmful hydrocarbons, which results in a dramatic reduction of exhaust fumes. It also lasts for up to five years in storage. Yes, you read that correctly - five years! This is great news for the environment and your health but it’s also much better for your lawn mower’s engine. You can learn more about Aspen fuel by heading over to the pros at Mower Magic.
However, there is a small catch with Aspen – it’s over twice the price of unleaded E10 fuel, roughly £21 for five litres. Nevertheless, given that a lawnmower runs for ages on a five-litre bottle of fuel, chances are you’ll get more than a full summer’s use out of a five-litre container. Given Aspen's Holy Grail properties, that's twenty one quid well spent in my book.