1997 Mazda Miata on 2040-cars

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This map reveals the cleanest vehicles based on location

Naysayers love to point out how dirty the electricity grid mix is when it comes to charging electric vehicles. Curmudgeons are eager to jump into any conversation about EVs to enlighten the lucky listeners about how plug-in cars contribute to pollution, sometimes even throwing in a dash of climate-change denial for good measure. (Thanks, buddy. Pray, tell me more about the plight of oppressed SUV owners.) Unless someone buys an EV just because they think they're cool (which, yeah, they often are), they probably have at least a passable understanding of their environmental pros and cons. As many EV owners are already aware, location has a lot to do with any particular plug-in car's carbon footprint. Still, there's always more to know, and knowledge is not a bad thing, especially if one uses it to do the right thing. That's why this handy-dandy map from Carnegie Mellon University is so interesting. CMU researchers have compiled information about the lifecycle greenhouse gas emissions of various EVs based on where they're charged, as compared to gasoline-powered vehicles. The researchers looked at the Nissan Leaf, Chevrolet Volt, and Prius Plug-In Hybrid versus the gasoline-dependent Toyota Prius hybrid and the stop-start-equipped Mazda3 with i-ELOOP and compared grams of CO2 emitted per mile. CMU takes into account the grid mix, ambient temperature, and driving patterns. CMU takes into account the grid mix based on county, as well as ambient temperature and driving patterns in terms of miles traveled on the highway or in the city. For instance, if you drive a Nissan Leaf in urban areas of California, Texas, or Florida, your carbon footprint is lower than it would be if you were driving a standard Toyota Prius. However, if you charge your Leaf in the Midwest or the South, for the most part, you've got a larger carbon footprint than the Prius. If you live in the rural Midwest, you'd probably even be better off driving a Mazda3. Throughout the country, the Chevrolet Volt has a larger carbon footprint than the Toyota Prius, but a smaller one than the Mazda3 in a lot of urban counties in the US. The Prius and Prius Plug-In are relatively equal across the US. Having trouble keeping it straight? That's not surprising. The comparisons between plug-in and gasoline vehicles are much more nuanced than the loudest voices usually let on.

World Car of the Year finalists announced

To say the 2014 Geneva Motor Show was packed full of news is an understatement as big as the show's home at the Palexpo convention center. Despite everything that we were able to cover during this year's show, there's still more coming out of Switzerland, including the announcement of the finalists for the 2014 World Car of the Year Awards.
We reported on the original list of finalists over three weeks ago, and now, that initial list has been pared down to three finalists for each of the five awards. The finalists were announced at a press conference by frequent Autoblog contributor and co-chair of the awards, Matt Davis (above).
The finalists for the overall title of 2014 World Car of the Year are the Audi A3, the BMW 4 Series and the Mazda3. The World Luxury Car of the Year will be either the Bentley Flying Spur, the Mercedes-Benz S-Class or the Land Rover Range Rover Sport, while the Performance Car of the Year will be awarded to the Chevrolet Corvette Stingray, the Ferrari 458 Speciale or the Porsche 911 GT3 (which, um, yeah...).

Mazda patent shows rotary placement in complex AWD hybrid layout

If we were playing alt-powertrain Bingo, a recent Mazda patent application filed in Japan would be one or two letters from victory. What's exciting about the patent, discovered by Japanese outlet T's Media via Motor Trend, is that while it makes a case for an internal combustion engine of any configuration, one of the drawings showing a rotary engine. The wild bit is that the whole powertrain comprises the ICE, a transaxle, two tiny in-wheel electric motors turning the front wheels, a third electric motor in the driveline, a capacitor, a lithium-ion battery, and three inverters. Motor Trend parsed the mechanics, and the way it reads, Doc Brown couldn't have done a better job. The rotary engine at the front turns the rear wheels, but not directly. Instead of a flywheel on back of the engine, the drawing shows a 25-kW electric motor and an inverter, then a driveshaft running to the transaxle. Along the axis of the transmission tunnel in a normal car, between the inverter and the transaxle, lies a 3.5-kWh battery running at 48 volts. MT writes that the electric motor can add its output to the ICE output to drive the rear wheels, or the e-motor can turn the rear axle on its own. Up front, two inverters and a double-layer capacitor join the ICE in the engine bay. The capacitor and tiny hub motors in the front wheels run at 120 volts, a higher voltage than the rest of the electrical system, so that the small in-wheel motors can generate the same torque as a larger motor running at a lower voltage. The AWD system acts on-demand. Given the signal, the capacitors discharge their energy to the wheel motors, and recover energy from braking. When the capacitors are at full charge, they send excess regen energy to the lithium-ion battery; conversely, the battery can recharge the capacitors when they're low and the front hub motors need power. The patent explains that the ICE works with the rear e-motor to drive the rear wheels at low speeds, the front motors called on to "generate an output only when a large output is required in the high vehicle speed range." The rather complicated system is focused on providing the benefits of a hybrid system and all-wheel drive, but at lower weight than one would expect. A rotary serves due to its compactness, but one of the drawings shows an engine with a V layout. Hub motors get dinged for adding unsprung weight, hence the small motors here.