Good Karma and the Future of Plug-in Vehicle MPG Ratings

Startup Fisker Automotive’s claim on Tuesday that its upcoming plug-in hybrid sports car, the Fisker Karma, will get the equivalent of 67.2 miles per gallon sounds downright modest relative to the triple-digit estimates we’ve been hearing in recent weeks from General Motors (230 MPG for the extended-range electric Chevy Volt) and Nissan (367 MPG for the all-electric LEAF).


The three models represent different technologies, but all of them use electricity and illustrate the need to rejigger the U.S. rating system for vehicle fuel economy. The EPA’s MPG ratings, with all their faults, give us a way to compare the relative efficiency of different models, and a similar shorthand is needed that accounts for kilowatt-hours and alternative fuel sources instead of only gasoline and tailpipe emissions.

Like the Volt and LEAF, the Fisker Karma has not received an official rating from the EPA, which has not finalized a new protocol for testing plug-in hybrid vehicles. But the startup’s approach to gauging the Karma fuel economy — based on methodology developed by the industry’s Society of Automotive Engineers, or SAE — may give us one of the more solid glimpses yet of what these ratings will actually look like down the road. (The EPA will likely consider SAE recommendations in its final rating system.) Fisker’s claim is high, but not wildly beyond consumers’ current reference points. (The 2010 Toyota Prius has a combined 50 MPG rating for city and highway driving.)

As The New York Times explained last year, the upcoming plug-in models from Fisker and other companies will not be the first alt-fuel technologies the EPA is tasked with rating: “Vehicles that run on pure electricity, mixtures of gasoline and E85 ethanol, compressed natural gas and hydrogen (fuel-cell vehicles now in the demonstration stage) all required adjustments — in layman’s terms, fudge factors — to the way energy consumption is reported. It is no longer a strictly scientific measurement, but takes into account compensating factors.”

SAE is working on a variety of standards and protocols for different hardware and systems ahead of the commercial rollout of plug-in vehicles between now and 2012. How vehicles will interact with the power grid has gotten much of the attention from automakers this year. (Without them, national distribution will be a big challenge since charging infrastructure in different regions and various plug-in models might not be compatible.)

Putting consistent fuel economy ratings in place early on could be just as important when it comes to winning over consumers long term. In some cases, overhyping a company or tech that ultimately falls short of expectations can cause skepticism and distrust in an industry that could otherwise be quite promising. (That’s part of what we’re seeing unravel now with biofuels.)

With plug-in vehicles, automakers may have well-founded methodology behind their MPG and MPGe (miles per gallon-equivalent) claims. But until an official rating system comes into place (the EPA is working on it), releasing these estimates with anything less than total transparency on the calculations means risking disappointment or disillusionment among consumers down the road.

According to the results of a survey out this week from Pike Research (which provides research for our subscription service, GigaOM Pro), 48 percent of consumers are interested in buying a plug-in hybrid vehicle — and 85 percent say improved fuel efficiency will be an important factor in their next vehicle purchase. So distrust in fuel economy gains could come at a high cost. The Karma seems to be making a solid, or at a least conservative claim, which could help with its, well, karma.

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