How much does the maintenance increase by with the addition of a natural gas fuel system per mile?

The correct choice indicates that the maintenance costs increase by 1 to 2 cents per mile with the addition of a natural gas fuel system. This aligns with industry observations that, while natural gas systems can be beneficial in terms of reducing fuel costs and vehicle emissions, they also introduce unique components and systems that require additional maintenance.

These costs stem from the need for specialized checks and services, including the upkeep of fuel lines, tanks, and pressure regulators that are not necessary for traditional diesel systems. Given that the increase is relatively modest—1 to 2 cents per mile—this reflects a balance between the advantages of using natural gas and the additional considerations for vehicle care and maintenance.

The other ranges do not accurately represent the typical increase seen in the industry, as higher amounts would suggest a more significant burden on maintenance than what is generally observed.