General Motors has begun offering a standard five-year or 100,000-mile warranty with its gasoline-powered Chevrolet Low Cab Forward trucks to qualified fleet customers, which would make it the only cab-over-engine manufacturer to offer these terms without an extended warranty.

GM began offering the warranty terms with its 2016-model-year Low Cab Forward 3500 and 4500, powered by a GM-sourced 6.0L V-8 Vortec gasoline engine that delivers up to 297 horsepower and 372 lb.-ft. of torque through a 6-speed GM transmission. The trucks are available in regular and crew cab models.

A qualified commercial customer must purchase five or more vehicles in the past 12 months or own or lease at least 15 vehicles in service. The fleet purchaser must also have a GM Fleet Account Number (FAN).

GM offers the trucks as rebadged versions of cabovers sold by Isuzu Commercial Truck of America. Isuzu offers the NPR and NPR-HD gasoline cabovers, which are powered by the same GM-sourced engine and transmission powertrain.

Isuzu offers a standard powertrain warranty of three years or 75,000 miles and optional five-year extended warranties of 100,000 or 120,000 miles.

"In the gas truck, GM and Isuzu are both getting a GM powertrain, and we can manage the warranty in the best way that meets the needs of our customers," said Paul Loewer, GM's medium-duty commercial product manager. "On the diesel truck, we follow the Isuzu warranty guidelines."

A third cabover manufacturer, Mitsubishi Fuso Truck of America will begin offering a trio of 2019 model-year cabovers powered by the gasoline engine in early 2018, including the FE130, FE160, and FE180 under an agreement with Power Solutions International, Inc. (PSI). The manufacturer made the announcement at the Work Truck Show earlier this year and hasn't announced the warranty it will offer on the trucks.

Hino doesn't currently offer a gasoline-powered cabover in its lineup.

Gasoline cabover warranties typically differ from diesel cabover warranties because the trucks see different usage patterns. Diesel cabovers typically rack up higher mileage numbers in their first three years or use compared to gasoline trucks. A typical Chevrolet gasoline cabover would be driven about 15,000 to 20,000 miles per year, while a typical Chevrolet diesel cabover would be driven 25,000 to 30,000 miles per year or more, Loewer said.

GM offers fleets alternative-fuel versions of its gasoline cabovers through PSI, including a dedicated compressed natural gas (CNG) or liquefied propane autogas (LPG) model. Fleets need to purchase the hardened engine package that uses special valves that can accommodate the higher pressure of these gaseous fuels.

Currently, GM is selling two gasoline cabovers for every three trucks sold, while Isuzu is selling about an equal number of diesel and gasoline cabovers, Loewer said.

Editor's note: An earlier version of this story has been corrected to report that GM offers its own 6-speed transmission, not the Allison 1000 transmission.