Improving fuel efficiency doesn't always require creating a new vehicle.

XL Hybrids markets modifications that allows fleet buyers to "upfit" their vehicles into hybrids.

So far, the company's efforts have focused on hybrid powertrains for vans, box trucks, and shuttle buses.

DON'T MISS: Ford Transit Van Gets Add-In Hybrid Kit For Better Fuel Economy (May 2015)

But now XL Hybrids is launching a plug-in hybrid system for pickup trucks as well—and it already has a large order from the California electric utility company San Diego Gas & Electric (SDG&E).

Dubbed XLP, the system leaves the original internal-combustion engine, transmission, fuel system, and exhaust intact. That allows owners to retain the factory powertrain warranty.

The system adds an electric motor and a lithium-ion battery pack with a capacity of "over 10 kilowatt-hours," according to XL Hybrids.

Coca-Cola Chevrolet Express van with XL Hybrids conversion

Coca-Cola Chevrolet Express van with XL Hybrids conversion

Those items add 650 pounds to the weight of the vehicle.

But plug-in hybridization can reduce fuel consumption by up to 50 percent, XL Hybrids claims.

The company noted that recharging the battery pack from a 240-volt AC Level 2 source takes less than one hour, but did not mention an electric-only driving range.

ALSO SEE: Coke Tests Add-In Hybrid System For Better Gas Mileage On Service Vans (Nov 2014)

It also didn't delineate which specific truck models will accept the XLP powertrain modifications, only saying the setup was designed for "half-ton pickup trucks from leading OEMs."

That likely means models such as the Ford F-150, Chevrolet Silverado 1500/GMC Sierra 1500, and Ram 1500.

Deliveries are expected to begin in the fourth quarter of 2017, and XL Hybrids already has a large pending order.

San Diego Gas & Electric substation

San Diego Gas & Electric substation

California utility San Diego Gas & Electric recently signed a memorandum of understanding to purchase up to 110 plug-in hybrid pickup trucks from XL Hybrids between 2017 and 2020.

SDG&E hopes to convert more than 20 percent of its fleet to "alternative-fueled vehicles" by the end of the decade.

It has already purchased more than 30 plug-in hybrid "bucket trucks," which are used to repair damaged power lines.

MORE: BYD partners with U.S. firm to launch all-electric garbage truck

Those vehicles can operate on battery power while repair work is underway, reducing both emissions and noise, SDG&E notes.

SDG&E is also undertaking a project to install 3,500 electric-car charging stations at 350 locations, including businesses and apartment complexes.

It's one of three California utilities involved in charging-infrastructure expansion projects approved by the state Public Utilities Commission over the past year.


Follow GreenCarReports on Facebook and Twitter