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Japan plans real-world diesel emissions test after companies fail

Japan's transport ministry plans to start real-world diesel emissions tests after an experiment found four models from Toyota, Nissan, and Mitsubishi that produced more nitrogen oxide (NOx) emissions than the nation's rules allow, according to The Japan Times. Regulators there usually only perform emissions checks in the lab. The VW diesel scandal has everyone double-checking their figures. Diesel versions of the Toyota Hiace van, Land Cruiser Prado, and Nissan X-Trail produced up to 10 times more NOx than allowed. The Mitsubishi Delica D:5 was up to five times over the limit, The Wall Street Journal reports. There was no evidence of defeat devices in the vehicles. Mazda performed well in the experiment, though. The CX-5 passed with nearly the same results on the road and in the lab. The Demio, better known as the Mazda2, did nearly as well with only slighter higher figures in the real world than in the controlled setting. The experimenters theorized the reason for the excessive emissions was that cold weather caused the engines' software to shut off the exhaust gas recirculation to prevent damage, according to the WSJ. However, this behavior also increased NOx production. Toyota, Nissan, and Mitsubishi don't have to worry about punishment from the transport ministry because this check was just an experiment. Their models already passed the mandated lab tests, which was the only requirement, according to The Japan Times. As governments begin greater real-world emissions tests, the results suggests diesels aren't very clean. A recent check in France found models from Ford, Renault, and Mercedes-Benz that didn't perform up to the standards. Regulators in India conducted similar evaluations and ordered VW to recall over 300,000 vehicles. Related Video:

Confirmed: Mazda Miata gets more power, higher redline, telescoping wheel

Our friend over at Road & Track, Bozi Tatarevic, has a keen nose for stuff just like today's Miata news, and he spotted an article by the Japanese car magazine Car Watch that details Mazda's upcoming updates. Car Watch actually got to drive the car, too. There's a lot to go through, but the highlight has to be confirmation of what we told you earlier this year about a significant power bump: The Miata will indeed get an increase of 26 horsepower, from 155 to 181. But the power's not the whole story. Mazda has increased the redline from 6,800 RPM to 7,500. It's not clear at this point where torque and power peaks are in the rev range, or how these changes affect low-speed drivability, but more revs are almost always a good thing and aren't likely to detract from the roadster's fundamental goodness. Car Watch reports that lighter pistons and connecting rods are fitted to help reduce rotational mass in the 2.0-liter inline-four. Some valvetrain changes were needed to support the higher redline, mainly stiffer valvesprings to prevent valve float. Mazda also changed the shape of the valves and optimized the intake ports to breathe better at higher RPM. The inner diameter of the exhaust ports were increased to flow better through a new muffler better tuned to the engine's new operating range. This confirms and gives a little more detail to what we reported earlier based on a leaked document from Mazda Canada. Car Watch also confirms that the revised Miata will get a low-inertia dual-mass flywheel, which should help absorb some vibration, noise and harshness from the higher-revving engine without losing too much of the directness that a single-mass flywheel provides. Mazda usually gets stuff like this right, so while we won't know until we get a chance to drive it whether the DMF feels "right," we're not too worried about it. There's also a telescopic steering wheel, a first in any Miata, which has a range of about 1.1 inches. That doesn't sound like much, but it should help folks with longer legs reach the wheel without having to crank the seat forward. Interestingly, Car Watch reports that the telescoping wheel was opposed by some in the company seeking to save every fraction of an ounce of weight, and to get it through, the company apparently had to change some of the material in the upper steering column from steel to aluminum to satisfy the weight-conscious. Little details like these are fantastic.

Car and Driver 10Best list cracked by Tesla Model S, BMW 3 Series left off

Car and Driver is keeping new blood pumping into its annual 10Best cars list with three new entries making it on for 2015 and a perennial favorite falling off. Among the biggest shocks this year is that the BMW 3 Series and 4 Series are no longer named, despite years of some portion of that lineup earning a mention. In another surprise, the Tesla Model S (specifically in S 60 trim to fit under the $80,000 cost cap) makes it to the 2015 roster and is the only electrically motivated member of the group. Despite the loss of the 3 Series, BMW isn't entirely shut out this year, because the M235i gets its name on the list. Car and Driver argues that the little coupe feels like a welcome throwback to the E46 chassis M3 of the early 2000s. In addition to the Model S, the final newbie to the annual group is the 2015 Ford Mustang GT. The inclusion of these new members knocks the Audi A6/A7 family and Ford Fiesta ST out from the 2014 rundown. The other seven models carry over from last year, including the Cadillac CTS, Chevrolet Corvette Stingray, Honda Accord, Mazda3, Mazda6, Porsche Boxster/Cayman and Volkswagen Golf/GTI. The 2015 10Best cars list certainly seems to have something for everyone from the hot hatch fan to the family man and even the green car driver, thanks to the addition of the Tesla. Head over to Car and Driver to read its detailed explanations for each vehicle's inclusion, but if you've got a difference of opinion or just really like the list, let us know in Comments. Featured Gallery Car and Driver 2015 10Best Cars List View 10 Photos News Source: Car and DriverImage Credit: Car and Driver, BMW, Cadillac, Chevrolet, Ford, Honda, Mazda, Porsche, Tesla, Volkswagen Auto News BMW Cadillac Chevrolet Ford Honda Mazda Porsche Tesla Volkswagen Convertible Coupe Hatchback Performance Sedan 10Best