The John Deere S120 is a 100 Series lawn tractor with a 22 HP V-Twin engine, 42-inch Edge mower deck, hydrostatic transmission, electric PTO, cruise control, and John Deere Easy Change oil system. It is built for residential mowing and sits above the entry S100 model.
General Specifications
Product Name
John Deere S120
Type
Lawn tractor / ride-on mower
Brand
John Deere
Series
100 Series
Production Status
Current model
Built In
Greeneville, Tennessee, USA
Engine
Briggs & Stratton 44N677 V-Twin gasoline
Fuel Type
Gasoline / petrol
Cylinders
2
Cooling
Air-cooled
Displacement
44.2 cu in / 724 cc
Engine Horsepower
22 HP / 16.4 kW
Rated RPM
3600 rpm
Transmission
Hydrostatic
Drive
2WD
Transmission Control
Side-by-side foot pedals
PTO
Electric clutch
Mower Deck
42 in / 107 cm Edge mower deck
Deck Lift
Spring-assisted hand-grip lever
Cutting Height
1 to 4 in / 2.5 to 10.2 cm
Front Tires
15×6-6
Rear Tires
20×8-8
Fuel Tank
2.4 gal / 9.1 L
Engine Oil Capacity
2.8 qt / 2.6 L with Easy Change system
Oil Change System
John Deere Easy Change 30-second oil change system
Battery
12V 300 CCA
Charging Output
8 amps regulated
Seat
15 in open-back seat
Cruise Control
Yes
Warranty
2 years / 120 hours bumper-to-bumper
Higher Than Average S120 Specs
22 HPV-Twin Engine
42 inEdge Mower Deck
724 ccEngine Size
2.4 galFuel Tank
Electric PTOBlade Engagement
S120 Compared To Average Lawn Tractor
Engine Power
22 HP
Average
18 HP
Deck Width
42 in
Average
42 in
Fuel Tank
2.4 gal
Average
2.0 gal
Best For
Residential lawn mowing
Small to medium-size yards
Homeowners wanting a V-Twin engine
Simple foot-pedal mowing control
Regular weekly lawn maintenance
Not Best For
Commercial mowing
Large acreage mowing
Heavy towing
Ground-engaging attachments
Rough paddock or field work
Engine
The John Deere S120 uses a 724 cc Briggs & Stratton 44N677 V-Twin gasoline engine rated at 22 HP. The V-Twin design is smoother than the single-cylinder engine used on cheaper entry-level lawn tractors.
Transmission
The S120 uses a hydrostatic transmission with side-by-side foot pedals. This gives simple forward and reverse control without manual shifting.
Mower Deck
The John Deere S120 comes with a 42-inch / 107 cm Edge mower deck. This is a practical residential deck size because it cuts faster than smaller mowers while still fitting many gates and tighter lawn areas.
Oil Capacity
The John Deere S120 maintenance sheet lists 2.8 quarts / 2.6 litres of engine oil with the Easy Change system. The Easy Change filter itself replaces about 0.8 qt / 0.76 L during the quick oil-change service.
Fuel Tank
The S120 has a 2.4 gallon / 9.1 litre rear fuel tank with an easy-read fuel gauge. That is enough capacity for normal home mowing without constant refueling.
Battery and Electrical System
The John Deere S120 uses a 12V 300 CCA battery with an 8 amp regulated charging system. Most practical replacements are U1 or U1R lawn tractor batteries with the correct terminal orientation.
Important Model Note
The John Deere S120 is a residential lawn tractor, not a compact utility tractor. It is made for mowing and light yard work, not loader work, tillage, heavy towing, or commercial use.
Summary
The John Deere S120 is a residential 100 Series lawn tractor with a 22 HP V-Twin engine, 724 cc displacement, 42-inch Edge mower deck, hydrostatic transmission, electric PTO, 2.4 gallon fuel tank, Easy Change oil system, and 12V 300 CCA battery. It is best for homeowners who want a smooth, easy-to-use 42-inch ride-on mower for normal lawn mowing.
