Not long ago a motorcycle with a fuel gauge was basically unheard of and even "low fuel" idiot lights were rare. Riders used advanced (and generally inaccurate) mathematics to calculate remaining mileage and, when the engine inevitably sputtered, switched over to a reserve tank that would let them nervously motor along a few more miles. Reva, an Indian company set to start shipping electric cars next year, plans to resurrect that most irritating sequence of events in their two-door NXR -- albeit with a modern spin. Now, instead of reaching down and turning a dial to get to that precious extra juice, drivers will need to call or text Reva HQ. Some overworked cust
