Home Transportation Electric Vehicles

Why the BMW i3 Extended-Range Electric Vehicle’s Tiny Fuel Tank?

BMW i3's Tiny Fuel Tank Barely Doubles its Electric Vehicle Range
BMW i3’s Tiny Fuel Tank Barely Doubles its Electric Vehicle Range

The BMW i3 is an extended-range electric vehicle [EREV], which is basically an electric vehicle [EV] with an onboard backup generator, but just a little one.

For some people, who aren’t fully on board with the limitations of electric vehicles, such as the Nissan Leaf, with a range of about 75 miles, an EREV could be the next best thing. Chevy Volt is a good example of an EREV, which has an EV range of about 37 miles before the gasoline-powered range-extender kicks in. Having a range extender offers peace of mind to those who might otherwise think they’ll be stranded, but there are hundreds of Chevy Volt owners who’ve racked up upwards of 10,000mpg. In other words, they use their EREVs just like EVs. The BMW i3, a recently released EREV, does things slightly differently, and mostly to please CARB [California Air Resources Board] regulations.

As an EREV, the BMW i3 has the potential to be nearly emissions-free, but only if drivers use it like an EV and ignore the range-extender. Chevy Volt’s range-extender has a fuel tank that extends the range of the vehicle up to ten times that of the lithium-ion [Li-Ion] battery pack alone, but BMW i3’s 2.4gal fuel tank will only provide another 80-100mi range to the 22kWh contained in the Li-Ion battery pack. This effectively doubles the range of the vehicle, but also puts it into a special CARB category, BEVx [Battery Electric Vehicle eXtended].

With 80-100mi estimated EV range, the BMW i3 is already more capable than the Nissan Leaf’s 75mi range, but with a limited-capacity fuel tank, won’t go as far as the Chevy Volt. On the other hand, BMW i3’s CARB BEVx designation also means that it can get a free pass on California HOV [high-occupancy vehicle] lanes.

Image © Inhabitat Foter.com CC BY-NC-ND

(Visited 231 times, 1 visits today)


  1. Once again, car companies present a Green vehicle that blatantly isn’t. Ignoring the fact hat electric vehicles aren’t green in terms of fuel consumption unless backed up by total cycle fuel savings including charging, there are issues with this one. If the vehicle does an extended run mixed cycle and uses a full fuel tank, it will cover, from the above information, a maximum of 37m electric and 100m petrol or 137m on 2.4 gallons or 57mpg. Beyond this distance it hasn’t got a recharged battery pack so then actually runs at a best mpg of 100/2.4=42mpg. This a maximum of 57mpg dropping down to 42mpg, hardly revolutionary fuel consumption for a small vehicle and not the planet saver we actually need.

    And as for the quoted Chevy Volt owners racking up 10,000mpg that is just a naive statement to make as the electricity generated in most cases probably came from fossil fuels. Statements like that just perpetuate the myth that electric vehicles in some magical way don’t use oil or other kinds of fuel. In reality, the total generating cycle isn’t particularly green in the vast majority of countries, it’s simply greener than the alternative of individually burning oil in transport vehicles.

    If it helps, I suspect I get way more than 10,000mpg from my non-electric bike, although you would still have to factor in the energy used in making it and the energy consumed by me in food which in itself takes oil to generate and distribute.


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.