Fueling Options for Mowers

As fueling options for passenger vehicles become more numerous — and more popular — these choices have expanded to off-road vehicles, too. That includes a resource many government fleets rely on — mowers.

Fueling options for mowers range from traditional gas and diesel, to biodiesel, propane, compressed natural gas (CNG), hybrid, and electric, each with its own benefits and drawbacks. The fuel options available for mowers depend on the size and type of mower.

Here’s what you can expect from various fueling types and how can make the right choice for your fleet.

Fuel options for mowers include:

• Gasoline, with lower acquisition and fuel costs than diesel
• Diesel, considered more durable than gasoline models
• Hybrid, which is becoming more popular in the government sector
• Propane, which emits less harmful emissions
• Biodiesel, a new option
• CNG, a domestic fuel
• Electric, which emits no harmful emissions during operation

Gasoline vs. Diesel in Mowers

Fleets looking to power mowers with traditional fuels like gasoline or diesel will find the two fuels often go head-to-head when it comes to the plusses and minuses of each.

“Each fueling option has its own unique combination of benefits and drawbacks,” said Rachel Luken, product manager for Jacobsen. “Gasoline, for example, is easily available but has a higher operating expense and is consumed faster than diesel. Diesel, on the other hand, requires a slightly higher initial investment for both fuel and machines, but diesel engines are more fuel efficient, last longer, and are more durable.”

“As a rule of thumb, gas engines are 25-30% less fuel efficient than similar diesel mowers,” Kevin Conry, marketing manager at Toro, added. With benefits and drawbacks related to both options, he said the choice between gas and diesel comes down to the individual needs of a fleet.

Mike Simmon, marketing coordinator, Grasshopper, reminds fleets that diesel fuel is cleaner than it has ever been in the past. Simmon said diesel engines are more efficient as well, which leads to decreased fuel use.

“According to field tests conducted by Grasshopper and end users, Grasshopper MaxTorque Clean Diesel mowers consume less than half the fuel compared to similar-sized gasoline and propane mowers, and can complete demanding jobs — such as mowing overgrown or heavy, wet grass — up to 50% faster,” he said. “Even though diesel fuel costs more per gallon than other fuel types, reducing fuel consumption reduces the cost of fuel over time and eases budgets that are weighed down by high fuel costs.”

Simmon also said availability and special fuel handling should also be taken into consideration. “The benefits of gasoline and diesel options are that both fuels are readily available and integrate well into existing fleets,” he said. “They do not require any special handling certifications, and on-site storage does not require specialized infrastructure investments.”

Propane Popular for Lower Maintenance Costs

Propane is known for producing fewer emissions than diesel or gas  — and for the abundant supply in the United States. Users can also see lower operating costs and reduced fuel spills — and refueling convenience for those fleets with on-site fueling stations.

“Typically in fleet applications, propane costs are less than gasoline and offer a comparable driving range to conventional fuel,” said Christine Chapman, Turf Equipment product manager at Kubota. “A prime reason behind propane’s popularity for grounds maintenance equipment is lower maintenance costs; the high octane, low-carbon, and oil-contamination characteristics result in longer engine life than conventional gasoline engines.”

Daryn Walters, director of marketing at Exmark Mfg., said recent advances in propane engine technology have erased nearly all of the fuel’s traditional drawbacks.

“The Kohler powerplant in the new Lazer Z S-Series zero-turn rider uses Electronic Fuel Injection (EFI) to maximize power and efficiency, with dramatically reduced fuel consumption and easy starting, hot or cold,” he said.

He said the increased fuel efficiency of the new engine allowed Exmark to achieve a full 7.5 hours of runtime on a single tank of fuel. The company’s single-tank system increases balance and reduces weight.

However, there are drawbacks to propane. “Propane mowers have lower emissions than diesel or gas but have limited availability in larger area mowers,” Conry said. “Propane-­powered units usually require more frequent fueling than gas and diesel mowers and usually have a drop in power performance.”

Simmon pointed out propane emissions are not necessarily better than today’s “clean” diesel. Citing EPA and CARB data for Tier 4 Final-compliant diesel engines, Simmon said carbon dioxide and carbon monoxide diesel emissions are significantly lower than propane when comparing hours of use. He said running a diesel engine for one hour will consume as little as 0.5 gallons of fuel, but a similar-sized propane engine will burn 2 gallons in the same hour.

Of note to cost-conscious fleets, the Propane Education & Research Council (PERC) may offer incentives to fleets that purchase and use propane-fueled mowers in exchange for sending PERC performance data. Companies that participated in the 2012 Propane Mower Incentive Program received $1,000 to purchase propane mowers and $500 for qualified converted mowers. In that study, landscape contractors reported the fuel cost them nearly 39% less than gasoline — and 60% less compared to diesel.

Overall, Chapman suggests the benefits of propane outweigh the drawbacks. “Propane is an environmentally friendly, domestically produced alternative fuel that saves customers time and money when compared to gasoline-­fueled mowers, due to on-site fuel delivery, less downtime as a result of approved operation on ozone action days, reduced fuel spillage, reduced maintenance costs, and longer engine lives,” she said.

A Checklist for Choosing the Right Mower Option

With various fueling choices on the market for mowers, how do you choose the right one? Here’s a simple checklist to follow when weighing the options.

• Determine the size of your mowing needs and your priorities. “Organizations need to sit down and determine the size of their mowing needs because fuel options will vary among mower sizes,” said Kevin Conry, marketing manager at Toro. “The next thing to do is prioritize what’s important to the organization in terms of sustainability, financial impact, and continuity with the rest of the fleet. For example, if a large percentage of an organization’s fleet runs on diesel, it makes sense to stick with what they know.”
• Make sure the mower will stand up to the needs and assess the costs. “Make sure the equipment will hold up to the mowing applications required, regardless of fuel type,” said Mike Simmon, marketing coordinator for Grasshopper. “Also, research how much the equipment will cost in maintenance and upkeep throughout the duration of the expected service life.”
• Compare current and future costs. “Review fuel use and costs from previous years thoroughly and compare how the available fuel types will affect costs over the expected life of the equipment,” Simmon suggested.
• Assess fuel availability and storage. “Look at local fuel availability and price,” said Bryan Holby, product manager at Jacobsen. “Compare that against what you’re currently using and your storing and transporting needs.”
• Consider federal and local emission regulations. “Review federal and local emission regulations to see what your legal responsibilities are,” Holby said. “You may be eligible for grants related to greener fuel sources.”

Hybrids Gaining Traction

Just like hybrid cars, hybrid mowers rely on traditional gasoline or diesel and electric power. This allows fleets to benefit from the upsides of both fuel sources.

“Probably the best of both worlds when it comes to fuel options is a true hybrid engine, which consists of a lower-horsepower gas or diesel engine paired with buffer electric power,” said Luken. “You get the ­power of a combustion engine combined with the fuel economy of an electric engine. The slightly higher initial investment can be returned rather quickly. We’ve seen a lot of interest from government customers in our electric and hybrid-powered machines.”

With hybrid technology, fleets can see major savings on fuel costs.

“A hybrid-powered solution would alleviate a portion of the equipment’s total cost of ownership by offering fuel savings up to 40% annually — by using a slightly lower horsepower and, where needed, using buffer batteries to manage peak power demands,” said Chris Fox, product manager for Jacobsen. “Government bodies have traditionally preferred diesel fuel because diesel engines are typically more durable and powerful. But with stricter regulations, we’re seeing more and more government fleets looking at hybrid as a viable alternative because it provides the power, fuel economy, and emission standards they require.”

The Denver Parks and Recreation department’s purchase of eight Jacobsen hybrid mowers is estimated to lead to fuel cost savings of almost $65,000 over five years.

Other Options: Electric, Biodiesel & CNG

As an alternative to traditional diesel, fleets can look to biodiesel. The most popular blend is B-20 — 20% biodiesel and 80% petroleum diesel — and can be used with some diesel-powered commercial lawnmowers without requiring any modifications.

Biodiesel offers benefits in the way of being a clean burning, renewable fuel source. At the same time, it can cost more per gallon than traditional diesel and may require a special additive or fuel tank heater to prevent gelling in low temperatures.

Luken says when it comes to mowers, biodiesel is still in the stages of proving itself in the market. “A newer option is biodiesel, which although more environmentally friendly, is harder to find, and quality/mix standards vary greatly among producers,” she said.

Another alternative-fuel option is compressed natural gas (CNG). CNG used in the United States is produced in North America, lessening dependence on foreign fuel oil. Because it’s lighter than air, CNG is also safer than other fuels in the event of a spill.

Because CNG mowers produce fewer emissions, fleets can see reduced maintenance requirements, fewer oil changes, and longer lifespans. And, according to the Clean Cities’ Guide to Alternative Fuel Commercial Lawn Equipment, CNG has been the least expensive U.S. motor fuel over the last decade.

Important for seasonally used mowers, natural gas doesn’t spoil or clog fuel systems during long periods of storage the way liquid fuels can.

Finally, while alternative fuels offer lowered emissions, electric mowers offer the most environmentally friendly option in that they produce no tailpipe emissions when in use. Electric power is also quiet and requires little maintenance. However, while these can be viable options for residential use, the demands of large mowing jobs can mean limitations for government fleets.

Advice for Navigating the Options

When it comes to choosing the right mower fueling option, experts suggest balancing total cost of ownership with an option that meets clean air regulations.

“Fleet managers need to look at the benefits and drawbacks of all fuel options, run cost/benefit analysis for each, and see how they align with federal and local regulations,” said Bryan Holby, product manager at Jacobsen. “Keep in mind the most cost-efficient option may not always meet your regulations.”

Conry agrees that looking at total cost of ownership is key. “Fleet managers should look at the overall cost of ownership for the life span of the mower when acquiring new equipment,” he said. “Ownership costs include labor, fuel, and maintenance across the number of years they plan to keep that machine in their fleet. They may also find that purchasing a larger mower can help them reduce their labor costs.”

Calculating Costs

For fleets comparing the costs of various fuel options, online calculators can be a valuable resource. These can calculate fuel consumption, fuel use, fuel costs per hour, emissions rates per hour, overall productivity, and trade-value for an accurate detailed analysis for various fuels. They can also be customized to local fuel prices and fleet size. See how much your fleet can save with one of these options: