United States Environmental Protection Agency (EPA) statistics of 2023 show that market share for the 4-Stroke push mower rose from 57% in 2018 to 72%, while that of its average annual growth rate reached 8.4%, far ahead of the -3.2% of the two-stroke. This is because of the general advantages of four-stroke technology: Taking the Honda HRN216VKA model as an example, its 160cc engine results in 34% thermal efficiency, 9 percentage points more than that of similar two-stroke models. Combined with the closed-loop fuel injection system, it reduces nitrogen oxide emissions by 63% (tested by the California Air Resources Board in 2022). Fuel efficiency-wise, the United States’ typical residential customer saves $28 to $42 annually in fuel costs. This is equivalent to 45% of the initial cost of equipment purchase over a period of 10 years.
It has driven technology evolution to step up environmental safeguards. Subject to California’s AB1346 Act, as from 2024, garden kit manufacturers will need to limit hydrocarbon exhaust levels to less than 10g/kWh, putting elderly two-stroke variants at risk of being made redundant – their normal emission ranges stand at 25-40g/kWh. The revenue hike of 82% results from the range of four-stroke products, according to Toro’s 2023 annual report. Its 22-inch SmartStow model reduced PM2.5 emissions to 0.8g/kWh by optimizing the combustion chamber shape, which is 20% tighter than new industry standards. A Nielsen consumer survey reveals that 68% of consumers would pay a 15% premium for the green 4-stroke push mower, which has encouraged manufacturers to allocate 35% of their research and development expenditure on low-emission technologies.
The advantage of maintenance expenses grew market competitiveness. Comparative tests drawn up by the Engineering Laboratory of the University of Wisconsin reveal that maintenance cycle of 4-stroke push mower prolongs by 60%, intervals of spark plug replacement are reduced from 50 hours per interval for two-stroke down to 120 hours per interval, and by $42-$58, it reduces the annual maintenance expense. Even more convincing is evidence from the commercial marketplace: After California-based landscape company GreenEarth replaced 30 two-stroke machines with Honda four-stroke machines, yearly fuel consumption dropped from 3,800 liters to 2,350 liters, downtime for maintenance went down by 41%, and equipment life increased from 4.2 years to 7.5 years. This economic benefit has increased the penetration rate for four-stroke models in the professional market from 29% to 57% within three years.
The innovation in technology continuously enhances user experience. The EXi series engines of Briggs & Stratton, due to lightweight construction, have reduced the overall weight of the 4 stroke push mower to 25.8kg, which is 18% less than the previous generation product, but the cutting torque remains at 4.2N·m. Popularization of the intelligent control system has increased the work efficiency by 30% – The adaptive speed regulation module integrated into the Troy-Bilt TB110 model is able to automatically adjust the optimal working range of 2000-3100rpm according to the density of the grass layer, saving 17% of fuel compared with the normal mechanical speed regulation. The Consumer Reports’ 2023 satisfaction survey reveals that the four-stroke variety is dominating in key metrics such as noise control (68dBA vs. 78dBA), vibration intensity (0.8m/s² vs. 1.5m/s²), and startup success rate (98% vs. 83%), which is why its user recommendation index is up to 91%. It is a 34 percentage point increase over the two-stroke variants.