John Deere S100 vs S120: Which Model Should You Buy?

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The John Deere company is quite fond of releasing almost identical lawn tractor models to the consumer market, so if you’re caught up in the web of how to purchase the best JD lawn tractor for you, I can very much understand. The S100 series can be tricky to decipher for someone who is seeking to buy a favorable residential-grade mower for their lawn without a hassle, but there’s nothing a good comparison couldn’t do to sort that out.

It’s crucial to fully understand the virtues of the models you’re examining so that you can select the lawn tractor that will help you tackle your mowing conditions best. When two lawn tractor models are involved, your most agreeable bet is to play by the one that ticks your requirements irrespective of reviews or informal inquiry.

In plain observation, the S120 is better than the S100 because it is more powerful, comfortable, and has a better level of endurance. In a quick pick for which mower is more efficient, the S120 is the right choice. Although that does not necessarily mean that the S120 is the right choice for you– I’ll explain why.

In this article, I’ll be comparing the John Deere S100 and S120 to ensure you select the most satisfactory lawn tractor to suit your mowing requirements. Let’s dive!

differences between john deere s100 and s120

5 Major Differences Between The John Deere S100 And S120

The best way to start is to understand the differences between the two models so that you can use them to your advantage.

A Measure Of Horsepower

The power capacity of a lawn tractor is easily the most agreeable determiner of which mower to quickly hop on in the market which is good, but not the most effective way to handle your decision-making.

The S100 is equipped with 17.5 horsepower in comparison to the S120 with 22 hp– the difference is big. It’s always a good idea for your lawn tractor to be properly powered to tackle challenging mowing tasks, but in some cases, that much power is not needed.

That is why you should consider the features of your yard and the frequency at which you use your mower. The size of your yard is a good place to start; if you mow ½ to 1 acre, you’d be fine with the S100, while the S120 will be a better match for 1 – 2 acres.

Following suit is how sloped your yard is and the manner of turf you would be running over; slopes and aggressive turf would need more power to get suitably stable results in the long term.

Engine Cylinder Setting

While the motors of the S100 and S120 are of the same brand, the cylinder installation differs in ways that could benefit you.

The S100 is equipped with a single-cylinder that consumes less fuel in comparison to the S120 with the V-twin double-cylinder engine. With the S100, you’d have the advantage of less frequent fuel refilling. However, the S120 double-cylinders will run smoother and be more efficient for tougher tasks in the yard. You can again use your yard as the yardstick; if you mow less than an acre, you’d save gas expenses with the S100. Other than that, the S120 is surely more productive for any mowing situation in comparison.

Seating Features

The seats for both models vary greatly and will determine your comfort in a measure of good and bad. Starting with the bad; the S100 seats are the least comfortable seats the models could be paired with. They are made out of hard plastic stuffed with foam in a miserly one-piece “L” shape that offers no support to the back or ventilation to the rear area. Over time, the plastic cover will crack allowing moisture to seep in, and then it wouldn’t be long for the whole seat to deteriorate especially if your lawn is bumpy.

The good seat in this case is paired with the S120. They’re not the best seats you can get, but they’re indeed far better than the S100 featuring nicer padding and better cover material, 15-inch back height which is better than none, and an open area between the back and saddle for ventilation. The common flop that both seats share is that they will be a tad small if you’re on the larger side.

The adequate solution to preventing bloodshot legs after two hours on either of the lawn tractors is to install a suspension seat– they have enough room for you and your pet to sit in with luscious padding, and an exquisite suspension so much that you could drink from a mug as you run over ditches and bumps.

Engine Air Filters

The S100 is equipped with a larger air filter in comparison to the S120 which renders a much cooler and safer environment for the carburetor of the machine. Increased airflow and minimal clogging are the right ingredients for increasing the lifespan of your lawn tractor and its engines, which is the upper hand the S100 has over the S120 in this case.

Price Tags

The difference in pricing for both models is great; the S100 will cost $2,000 – $2,200 in comparison to the S120 which costs $2,500 – $2,700 depending on your dealer.

similarities between john deere s100 and s120

6 Similarities And Standard Features Of The S100 and S120

Speed And Maneuverability

The velocity and sensitivity to steering for both the S100 and S120 are the same. Both models run at a forward speed of 5.5 miles per hour and a reverse speed of 3.2 mph which is adequate for residential grade mowing and other activities such as towing to match the transmission of the machines through and through.

Deck Type And Cut Quality

The S100 and S120 are equipped with the standard beginner-level deck which is the 42-inch Edge 13-gauge steel cutting deck with double anti-scalp wheels– and the cut quality is impeccable! Because of the moderate speed of the lawn tractors, the amount of time the decks settle over the turf is efficient for a clean and assertive cut rid of stragglers and turf tears. For comparison, some commercial-grade lawn tractors come with a tow mode speed that allows the mower to run as slow as the S100 and S120 for the same cut quality you get.

Tire Size And Stability

The tires on both models are of the same size and quality; 13×6-6 at the front and 20×8-8 at the rear. Although the lawn tractors are stable on flat plains, they cope miserably on slopes due to the tire sizes. I strongly advise you to maintain a 12-degree angle and nothing more when handling slopes with these models. Some lawn tenders climb up to 13 degrees, but it’s not advisable.

Preferably, mow up and down other than side to side to ensure the safest experience. Another thing you could do to manage the situation is to tweak the tire pressure to suit your yard. There are many tire pressure tips and tricks you can use to your advantage.

PTO System

The PTO system on both models is the same; on the S100 and S120, you will find the manual PTO lever that is responsible for engaging and disengaging the blades as a safety feature. Although the electric PTOs on the larger models up the S100 series are fancier and more intuitive to use, they don’t last as long as the manual PTOs that your S100 or S120 is equipped with.

Fuel Tank Capacity

The standard fuel tank capacity for both models is 9.1 liters respectively. While the S100 can mow your yard twice with a full fuel tank, the S120 might flunk because of its double-cylinder motor. Nevertheless, each model is properly equipped with adequate fuel capacity for the manner of work you should put it through.


Both the S100 and the S120 have the residential-grade warranty which is the 2-year/24-hour bumper-to-bumper warranty on both parts and labor.

Frequently Asked Questions

How Long Can The S100 & S120 Last?

The S100 and S120 lawn tractors can last for 8 – 9 years depending on how well they’re maintained. However, this is the average range because the mowers can last even longer when they are exposed to less work than is usually required.

Can The S100 & S120 Mulch Well?

Mulching is a different ball game when dealing with beginner residential-grade lawn tractors, and honestly it isn’t the best with these models. Although you’d mulch better with the S120 than the S100 because of the extra horsepower, both riding mowers will only do a fair job.

Can The S100 & S120 Tow?

The S100 and S120 make good towing machines as long as you don’t exceed the required towing capacity which is dependent on you and your mower’s weight. The S100 weighs 414 lbs while the S120 weighs 444 lbs; the general rule of thumb is for the towing equipment to not exceed the weight of the mower itself.
Remember that since you are sitting on the machine, you will influence the overall weight of the lawn tractor. Now, take your weight and your mower’s weight and divide it by two, then sum up the halved figures to produce your lawn tractor’s towing capacity. Read “Can You Tow with a Lawn Tractor” for more information.

Can The S100 & S120 Plow Snow?

The S100 and S120 can certainly plow snow because of their stability and power as long as you push loads of snow within the capacity of your lawn tractor. Make the most benefits out of your riding mower all through the year by affixing the most favorable snow plow to your machine. Here’s everything there is to know about plowing snow with your lawn tractor.

Does The S100 & S120 Come With Other Deck Sizes?

The S100 and S120 are equipped with 42-inch decks only. It’s possible to install a larger deck but it’s not advisable if you’re seeking to preserve the quality and lifespan of the machine.

Final Words

If a competition is set up, the S120 will easily scale for the extra strength and comfort it provides. However, since this comparison is to deduce the best option suited for you, the only judge for this debate will be your requirements. I suggest you ponder on the differences and similarities of each model and relate them to your lawn’s needs so that you can make the most favorable selection for the long run. Good luck!

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EL Mehdi (Medi), the founder and voice behind Desired Lawn Mower. He is a riding mower enthusiast who enjoys spending more time discussing and covering various ride-on mower topics. He has been active in the industry for years comparing models of different ZTR and lawn tractor brands.