6 Best Self-Propelled Gas Lawn Mowers Under $400 2025

This brute-force performer redefines what’s possible in the sub-$400 self propelled mower category, delivering lawn-flattening efficiency with its 22-inch cutting deck and industrial-grade Briggs & Stratton 163 cc EXi675 engine. The single-speed front-wheel drive system takes real effort out of mowing, making it a godsend for those with uneven terrain or persistent back strain. With mulching, bagging, and side discharge all built in—and a 19-gallon catcher included—it tackles every yard condition without compromise, while the 6-position single-lever height adjustment makes dialing in your ideal cut a one-second task.

In real-world testing, the SENIX LSSG-H2 powers through thick grass with minimal slowdown, thanks to its high-torque engine and optimized blade airflow design. The 8-inch front and 11-inch rear wheels roll smoothly over bumps and slight inclines, though steep hills expose the limits of front-wheel drive traction. At 22 inches wide, it cuts fewer passes across medium yards—saving time—but the width does make tight turns around shrubs or trees a bit clunky. The washout port is a small but critical detail, making post-mow cleanup fast and mess-free.

Compared to the AMERISUN models, this SENIX stands taller with its larger deck, bigger bagger, and more powerful engine, making it a better fit for medium to large lawns where speed and capacity matter. While heavier than most at nearly 90 lbs, the trade-off is rock-solid stability and consistent cutting performance. It’s not as nimble as rear-wheel drive models on slopes, but for flat to gently rolling yards, it’s the most complete, no-compromise package under $400—outperforming rivals in both build quality and feature richness.

The AMERISUN 170cc self propelled mower hits a sweet spot of power and practicality, making it a standout mid-tier option for homeowners who want serious cutting muscle without overspending. Its 170cc OHV air-cooled engine delivers smooth, consistent starts and maintains RPMs even in thick grass, outperforming many in its class. The rear-wheel drive system is the real game-changer—providing superior traction on slopes and wet terrain, which is rare at this price point. With mulching, bagging, and side discharge, plus a 1.4-bushel grass catcher, it’s built for real-world versatility.

During testing, the mower handled damp morning grass and slight inclines with confidence, thanks to its deep-tread rear tires and balanced weight distribution. The 21-inch steel deck covers ground efficiently, though it’s not quite as fast as 22-inch models—meaning more passes on larger lawns. The 6-position height adjustment is smooth and reliable, letting you adapt to seasonal grass growth with ease. However, the recoil start, while dependable, lacks the refinement of primer-assist systems found on higher-end models, requiring a firm pull in cooler weather.

Pitted against the SENIX LSSG-H2, this AMERISUN trades a bit of deck width and engine refinement for better hill performance and lighter handling. It’s not the fastest mower out there, but for yards with slopes or mixed terrain, its rear-wheel drive gives it a decisive edge. It’s also more compact and easier to store than bulkier models, making it ideal for homeowners with medium yards and uneven ground—delivering maximum value where traction and reliability matter most.

Don’t let the modest price tag fool you—this no-frills powerhouse punches well above its weight with a 6-speed variable transmission that lets you match mowing speed to your stride, a rarity in budget mowers. The 141cc 4-cycle engine delivers surprisingly strong torque for its size, effortlessly chewing through standard grass and light overgrowth. Its rear-wheel drive and deep-tread spike tires offer unexpected grip on wet lawns and inclines, making it a stealth performer for sloped or uneven terrain. At just 20 inches wide, it’s nimble in tight spaces, perfect for small yards with flower beds or tight corners.

In real use, the mower shines with its lightweight agility and intuitive speed control, letting beginners and older users mow without strain. The 7-position height adjustment offers fine-tuned precision, while the volute-spiral deck boosts mulching efficiency—turning clippings into fine fertilizer with minimal clogging. However, the 50L (1.77-bushel) bagger, while large, sits high and can throw off balance when full. On thick, tall grass, the engine occasionally bogs down, revealing its limits compared to 170cc models.

When stacked against the SENIX LSSG-M9, this mower offers more speed options and better maneuverability but sacrifices deck width and engine durability. It’s not built for half-acre lawns, but for small to medium yards under 1/4 acre, it’s a smart, agile, and shockingly capable choice. For those who value walk-matching speed and hill grip over raw cutting width, it delivers exceptional performance per dollar—beating pricier models in responsiveness and user control.

Engineered for challenging terrain, the SENIX LSSG-M9 rises to the occasion with front-wheel drive and rugged 8”/11” tires that conquer uneven ground and sloped lawns with surprising confidence. Its 140cc Briggs & Stratton engine, while modest on paper, delivers smooth, low-vibration starts thanks to the Prime ‘N’ Pull system, making it one of the most user-friendly mowers for older or less experienced operators. The 21-inch cutting deck strikes a balance between speed and maneuverability, ideal for medium yards with obstacles or elevation changes.

In real-world use, the mower handles patchy, bumpy lawns without scalping, thanks to its dual-lever height adjustment and low-profile blade housing. The 6 cutting heights (1.25”–3.75”) are easy to switch, though doing both wheels manually takes more time than single-lever systems. The 16-gallon bagger is sufficient but fills quickly in lush grass, and the mulching performance is decent but not elite—fine clippings require dry conditions. On flat terrain, it feels less powerful than 170cc rivals, but on slopes, it holds its own.

Stacked against the AMERISUN B0F6CRFTTF, this SENIX model offers Briggs & Stratton reliability and a smoother start system, but lacks rear-wheel drive and a larger catcher. It’s not the fastest or most powerful, but for sloped or uneven yards where stability and consistent starts matter, it’s a smart, dependable choice. It sacrifices raw power for user comfort and terrain adaptability, making it best for homeowners who value reliability and ease of use over maximum cutting speed.

If mulching mastery is your goal, the AMERISUN B0FCFHCX42 is a precision-crafted performer that turns clippings into fine, fast-decomposing mulch thanks to its optimized 21-inch steel deck and high-lift blade design. The 170cc OHV forced-air-cooled engine maintains consistent RPMs, ensuring the blade spins at full power even when recirculating thick grass—critical for effective mulching. With 3-in-1 functionality, a 1.4-bushel catcher, and six adjustable heights, it’s a complete package for homeowners who want lawn health and cleanliness in one pass.

Field testing confirms its superior mulching performance, especially in dry conditions—clippings are finely chopped and evenly dispersed, feeding the soil without clumping. The foldable handle makes storage a breeze, and the rear-wheel drive provides solid traction on mild slopes. However, in wet grass or tall weeds, the deck can clog more easily than competitors with washout ports. The side discharge chute, while functional, lacks a deflector, sending clippings unpredictably.

Compared to the PowerSmart B0F1C8RMGJ, this AMERISUN offers better mulching geometry and a more user-friendly handle fold, but similar engine and deck specs. It doesn’t have a washout port, which is a missed opportunity. Still, for eco-conscious users who prioritize soil enrichment and clean cuts, it’s the top mulching specialist in this lineup—delivering superior lawn conditioning at a competitive level of power and ease.