Independent testing shows 21.2% reduction in fuel consumption with XL Hybrids retrofit system

The XL Hybrids system in place. Click to enlarge.

Testing at an independent EPA-certified vehicle laboratory showed a 21.2% reduction in fuel consumption achieved with XL Hybrids’ aftermarket hybrid electric powertrain on a light-duty cargo van on the UDDS cycle (urban conditions). The company had been targeting a 20% reduction.
The tests were conducted on a light-duty chassis dynamometer test cell featuring a twin-roll Clayton dynamometer. The testing process compares fuel economy performance from the vehicle in its original condition with the performance using XL Hybrids’ charge-sustaining hybrid system. The test was completed using a Chevrolet 2500 Express cargo van fitted with the original equipment manufacturer’s 4.8L engine and 6-speed transmission.
XL Hybrids’ hybrid electric powertrain is a low-cost, low-risk, bolt-on, post-transmission parallel hybrid technology designed for Class 1–3 commercial vehicles that integrates seamlessly with the conventional internal combustion engine and transmission. The current 2012 powertrain consists of a 2 kWh lithium-ion battery pack, a 40 kW (53 hp) electric motor and a proprietary hybrid control system that operate with the OEM internal combustion engine and automatic transmission.
Integration of the XL Hybrids (XLH) system is right at the tail housing of the transmission. XLH removes the stock tail housing, and replaces it with the XL system with integrated electric motor. There is no removal of major components of the OEM powertrain, notes Justin Ashton, co-founder and vice president of business development.

What’s unique about our system is that it’s bolt-on—we don’t have to modify the ECU or the TCU. Our hybrid controller connects to the CAN; our controller is read-only. We listen to CAN, collect signals. That totally gets around the problem of having to create a whole new set of controls for the engine and transmission. It also doesn’t necessitate a recertification of the vehicle for safety, emissions.

The underlying internal combustion engine is unaffected because of how we integrate with the vehicle. We don’t touch the warranty. Our own components have a 3 year, 75,000 mile hybrid system warranty.

—Justin Ashton

This year, the company will release between 30 to 50 fleet trials, Ashton told Green Car Congress, using the 2012 system. XLH engineers have already designed the next-generation release, in which the battery pack is downsized to 1.5 kWh, Ashton said. Both the 2.0 kWh and 1.5 kWh packs were in essence “off-the-shelf”—i.e., already developed for an OEM and sold worldwide, to reduce XLH’s engineering costs.
The current 2.0 kWh pack sits inside the vehicle; the 1.5 kWh pack is intended to fit between the frame rails.

From a higher-level perspective, what’s important to customer is the benefits of fuel consumption reduction, as opposed to what the technology is. OEMs can get higher mpg improvements by using different architectures. Our focus has always been from day one to be cost-effective. We rely on customer interest for the ROI threshold. They’ve told us if you can get this to an under 5-year payback, then we can talk.

—Justin Ashton

The planed price for production in 2013 for the full release system is starting under $8,000 including installation, Ashton said, with fleet discounts beyond that. The system is designed to be installed in about 4 hours, faster at a commercial upfitter.
In May, XL Hybrids signed an agreement with Henley Transmission Services, LLC, the largest franchise holder of AAMCO automotive service centers, to certify AAMCO technicians to install and service XL Hybrids’ hybrid-electric conversions.
XL Hybrids was founded by MIT alumni and is based in Boston.