According to reports from the United States Environmental Protection Agency (EPA) information, compared to traditional two-stroke lawn mowers, fuel efficiency of the 4 stroke push mower is improved by approximately 30%-50%, using just 0.3-0.5 liters per hour of fuel, whereas the two-stroke uses 0.7-1.0 liters. According to an average annual usage of 50 hours, fuel cost savings will be approximately $45 to $75 (based on the average price of gasoline at $3.8 per gallon in 2023). For instance, Toro’s 2022 tests showed that the fuel efficiency of its four-stroke model, TimeMaster 30, was as much as 1.2 acres of grassland per gallon, with a 40% larger operating area than similar two-stroke models.
On the environmental protection indexes, the hydrocarbon emissions of the 4 stroke push mower are 72% lower than those of the two-stroke model, and it complies with the EPA Tier III emission standards. A study by the California Air Resources Board (CARB) estimates that if 10% of two-stroke lawn mowers in the United States were replaced by four-stroke ones, around 23,000 tons of volatile organic compound (VOC) emissions annually could be avoided, equivalent to the emission of 48,000 cars. Take, for instance, Briggs & Stratton’s 850 series engine. Its nitrogen oxide emissions are only 0.5 grams per kilowatt-hour, 60% lower than the industry average.
Maintenance cost-wise, the oil change cycle for four-stroke engines is as much as 50 hours, while for two-stroke engines, fuel needs to be mixed every 25 hours. According to statistics of consumer reports, the total expense of owning the 4-Stroke push mower for 10 years (purchase price, fuel, and servicing) is around $650, which is 28% cheaper compared to the two-stroke variant. For example, the crankcase capacity of the model Honda HRX217VKA is 0.58 liters. With the full pressure lubrication system, the lifespan of key components can be extended to 1,200 hours, 2.3 times longer than ordinary models.
From the perspective of user experience, the amplitude of vibration of the four-stroke engine is reduced by 45%, and the noise level is controlled within 75-85 decibels (90-100 decibels for the two-stroke engine). Its real test of John Deere’s S100 series shows that when its no-load rotating speed is 2800 RPM, its vibration acceleration is only 3.2 m/s², 32% lower than the industry average. On the operation efficiency side, the 4-stroke push mower with 22-inch cutting head can mow 0.5 acres of lawn in an hour, 15% more than the same size two-stroke model, which is equivalent to saving 25 minutes of working time for 5,000 sq ft lawn.
Market data indicate that four-stroke models held 67% of push-type lawn mower market share in the U.S. market in 2022 with a growth rate of 8.4% annually. The sales data of Home Depot demonstrates that the repurchase rate of the 4-stroke push mower priced at a range of $299- $499 is 19% greater than its two-stroke counterpart primarily because of its 3-5 years failure interval cycle (MTBF). For instance, Cub Cadet CC700 cast iron bushings’ design loads its transmission system capacity to 180 pounds and increases its operating life by four times over those of aluminium components, hence making it the tool of choice by professional horticultural businesses.