How often do you need to mow your lawn? What’s the area of your lawn? How much time have you got?
Well! Answering those could help you find the right HP value for your mower. The HP rating suggests how much work a machine can do over a specific time.
While horsepower is used to tell about how powerful a riding lawn mower is, torque is used for push mowers.
But does HP matter in lawn mowers? We’ll find out about it in the article below.
Well, there’s another area to discuss. How much HP do you need? A riding mower operator needs to power multiple mower areas like wheels, blades, and others.
However, a walk-behind mower requires lesser power as it needs to power only the blades.
While HP varies with the type of lawn mower, the usual range lies within 3 to 40. Bigger mowers have over 20 HP engines while smaller ones lie around 4 HP.
How to Measure Horsepower?
The fundamental idea of horsepower refers to the work a machine does over a particular time. Technically, 1 HP equals 33000 foot-pounds per minute.
In simple terms, a 1 HP engine performs a work of 33,000 pounds over a distance of one foot in 1 minute.
Are you wondering how does HP matter in lawn mowers? Keep reading to explore why it’s a vital choice when buying your next mower.
How does horsepower apply to lawn mowers?
A push mower’s power is mainly measured in terms of torque, but HP is the term that defines power for a riding mower.
However, replacing your push mower with a riding one can be daunting due to the lack of a straight method to compare both power metrics.
But you can compare the horsepower of two mowers using this:
- Multiply the torque by RPM
- Divide the result by 5250
Although it’s not a scientific approach to discovering the horsepower you need, it gives you a good idea.
HP for Different Lawn Mower Types
Usually, riding mowers are the ones that use HP to define how powerful they are. As you know mowers are of different types, we will consider this type for the discussion.
Mowing experts suggest buying a riding mower if you have over half an acre of lawn. Others like push and self-propelled mowers will need more time and effort to cut that much.
Comparatively, riding mowers makes the work easier while consuming less time. These come with a range of 12.5-20 or higher HP values.
In case, your garden is flatter and smaller, you can opt for a mower that lies on the lower end of the ranges.
But for a big yard or a lawn with huge grass, bumpy or hilly areas, you should get a riding mower with 20 HP power.
Lawn Mower Design and Horsepower
In addition to the size of the mower and engine, other factors also affect the horsepower of a lawn mower. You can increase HP directly in these ways:
- The governor flap beside the flywheel can blow out in case the engine is spinning very fast. This slightly closes the carburetor and decreases the HP.
- Using a high-octane gas helps increase the mower’s horsepower.
- Examine the muffler for any damage or cracks as it can reduce horsepower if it isn’t fully sealed.
- Regularly clean or replace the filer to avoid loss of horsepower.
What is the Right HP for my Lawn Mower?
More challenges in mowing a lawn need higher power of your mower’s engine. You can find the right engine power with these guidelines:
- Less than 3-acre lawns need an 11-25hp mower
- More than 3-acre lawns need at least a 19hp mower
- For hilly and uneven lawns, the mower should be at least 20hp
- For flat lawns, the mower HP should lie within 11 to 20
- A rear engine mower needs 11-20hp power
- For lawns with slippery and wet grass, get a mower with 19-25hp
- For stand-on mowers, 15-20hp is an ideal range
- For zero-turn mowers, get a mower with 19-27hp power
How are horsepower and torque related?
Are you a beginner with the terms torque and horsepower? Then, torque is the capacity of completing work and horsepower defines how rapidly a machine can complete a strenuous job.
Mathematically, multiplying torque with RPM results in HP. While we covered this earlier as well, it’s not much difficult to understand the relation.
Thus, for more power, an engine needs higher values for torque, RPM, or both.
How Does HP Matter in Lawn Mowers?
As it’s already clear, horsepower defines the power of a riding mower. Choosing the right HP value is crucial for effective mowing.
Let’s take an example to understand “how does HP matter in lawn mowers?” If you use a higher HP engine with a residential mower, here’s what could happen:
- It will work at the same speed and a similar blade tip speed.
- Even if the blade tip speed gets faster, it would lead to faster wear and tear of spindles.
But working with a higher than required HP will make the mower heavier and louder. Plus, it will make the mower go off-balance.
FAQs
What HP is good for a lawn mower?
The choice of HP depends on various factors including lawn size, type of area, and mower type.
Usually, gas-powered walk-behind mowers have 2-7hp engines while riding mowers have 13-30hp engines.
How much HP should a lawn mower have?
You can find the right HP for your mower based on the width of its cutting deck.
A mower with a 42-inch deck needs a minimum of 14hp while 14-16hp is ideal for a 42-46 inches cutting depth. Similarly, 46-54 cutting decks need 18-24hp engines.
What is good torque for a lawn mower?
Your lawn mower’s torque is good if it gets the job done well. That said, it depends on your mowing needs.
A 4.5-5.5 ft-lbs torque is good for a flat, small lawn you cut regularly. A medium to heavy-duty mower will be a good pick for a lawn with bigger size or tall and thick grass.
A medium mower would have a torque of 6.25-6.75 ft-lbs while the value for a heavy-duty mower will be 7-8.75 ft-lbs.