The idea of a Ford F-Series hybrid pickup truck has now been around since August 2011, but its maker now expects to launch such a truck sometime during 2020.

Meanwhile, on Tuesday, Boston-based XL Hybrids unveiled both a Ford F-250 Super Duty pickup fitted with its XLH hybrid system and an F-150 light-duty pickup with its XLP plug-in hybrid system.

The pair of trucks will be shown to the public on the company's display at the NTEA Work Truck Show, which will run from March 6 through 9 in Indianapolis.

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The hybrid and plug-in hybrid hardware is supplied in the form of a "ship-through uupfit," meaning truck owners buy their pickups through dealerships, which then hand them over to XL to be modified with the hybrid systems.

Production of the XLH system for the F-250 Super Duty range will start in March, the company said in a release, calling it the first time ever that customers can get a hybrid version of a heavy-duty Ford F-Series pickup.

Its add-in hybrid systems maintain the trucks' towing, hauling, and all-wheel-drive capabilities, and allow for a full range of utility applications just as the standard vehicles do.

XL Hybrids system for GM vans

XL Hybrids system for GM vans

XL Hybrids will also announce that its XLP plug-in hybrid upfit is compatible with more of the large number of F-150 configurations, including the SuperCrew version with four passenger doors and the ability to carry six occupants.

That plug-in hybrid system—which adds a 15-kilowatt-hour battery pack under the bed and an electric motor between the transmission and rear axle—is now available for regular-cab, SuperCab, and SuperCrew versions, the three main cab styles Ford offers.

The improvements to fuel efficiency for the XLH hybrid system in an F-250 are cited as 25 percent, with as much as a 50-percent boost to the effective fuel economy for the plug-in hybrid F-150.

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The best 2018 Ford F-150 pickup version, fitted with a 2.7-liter turbocharged V-6 engine and a new 10-speed automatic transmission, is 20 mpg city, 26 highway, and 22 mpg combined.

Fuel-efficiency ratings for F-250 pickups aren't offered by the EPA because they are not required for heavy-duty vehicles, even if they are operated as personal transport.

Trucks fitted with XL Hybrid systems have now covered more than 60 million road miles in the hands of customers, the company said, noting that its expanding array of compatible vehicles comes from requests by existing and potential customers.

Coca-Cola Chevrolet Express van with XL Hybrids conversion

Coca-Cola Chevrolet Express van with XL Hybrids conversion

"We continue to be focused on delivering the most seamless, cost-effective fleet electrification solutions for [the] vehicles that our customers ask for," said Clay Siegert, XL's chief operating officer.

Fleets that have XL Hybrids systems fitted to their trucks retain Ford's original warranty coverage, and XL warrants its hybrid powertrain for three years or 75,000 miles.

XL also collects data on the daily operations of the hybrid and plug-in hybrid systems it installs, letting users measure their fuel efficiency, reductions in carbon-dioxide emissions, and other measures of performance.

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Ford and Toyota announced a joint project to cooperate on developing hybrid systems for full-size pickup trucks and SUVs in August 2011, but Ford abruptly withdrew from the partnership in July 2013 after the completion of a feasibility study.

General Motors offered a Two-Mode Hybrid system for its Chevrolet Silverado and GMC Sierra pickup trucks from 2009 through 2014, and the same system in its Cadillac Escalade, Chevy Tahoe, and GMC Yukon full-size SUVs.

Sales totaled roughly 30,000 units among all vehicles over several years, and GM no longer offers a hybrid system on any vehicle above a mid-size passenger sedan.