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Is the skill of rev matching being lost to computers?

If the ability to drive a vehicle equipped with a manual gearbox is becoming a lost art, then the skill of being able to match revs on downshifts is the stuff they would teach at the automotive equivalent of the Shaolin Temple. The usefulness of rev matching in street driving is limited most of the time – aside from sounding cool and impressing your friends. But out on a race track or the occasional fast, windy road, its benefits are abundantly clear. While in motion, the engine speed and wheel speed of a vehicle with a manual transmission are kept in sync when the clutch is engaged (i.e. when the clutch pedal is not being pressed down). However, when changing gear, that mechanical link is severed briefly, and the synchronization between the motor and wheels is broken. When upshifting during acceleration, this isn't much of an issue, as there's typically not a huge disparity between engine speed and wheel speed as a car accelerates. Rev-matching downshifts is the stuff they would teach at the automotive equivalent of the Shaolin Temple. But when slowing down and downshifting – as you might do when approaching a corner at a high rate of speed – that gap of time caused by the disengagement of the clutch from the engine causes the revs to drop. Without bringing up the revs somehow to help the engine speed match the wheel speed in the gear you're about to use, you'll typically get a sudden jolt when re-engaging the clutch as physics brings everything back into sync. That jolt can be a big problem when you're moving along swiftly, causing instability or even a loss of traction, particularly in rear-wheel-drive cars. So the point of rev matching is to blip the throttle simultaneously as you downshift gears in order to bring the engine speed to a closer match with the wheel speed before you re-engage the clutch in that lower gear, in turn providing a much smoother downshift. When braking is thrown in, you get heel-toe downshifting, which involves some dexterity to use all three pedals at the same time with just two feet – clutch in, slow the car while revving, clutch out. However, even if you're aware of heel-toe technique and the basic elements of how to perform a rev match, perfecting it to the point of making it useful can be difficult.

Nissan Leaf sales get January jump as Chevy Volt trends downward

The cold January sales dip hit both the Nissan Leaf and the Chevy Volt last month, but when compared 2014 to 2013's first-month-of-the-year sales totals, one of the two early plug-in vehicles obviously came out on top. The top Leaf market also shifted away from Atlanta for the first time in months. Last year, the Leaf sold just 650 units in January, but it managed to move 1,252 last month, a 92.6-percent increase over 2013 but a big drop from the 2,529 sold in December 2013. Paige Presley over at Nissan told AutoblogGreen that the Leaf has now broken sales records for 11 months straight and that, "we see unique seasonality with some December pull-ahead demand based on federal and state tax incentives." The number one Leaf market also shifted away from Atlanta for the first time in months, moving back to San Francisco. That change could be short-lived. "We had some inventory constraint issues early in the month in Atlanta with end-of-year demand depleting stock," Presley said. "By the time we resolved that, the weather hampered sales." There was not as much good news on the Chevrolet front. Last month, the Volt sold 918 units, down from 1,140 in January 2013 and 2,392 in December 2013. It also marks the first time the Volt has sold in the three-digit range since January 2012, when it sold 603 copies. That string of solid months means that the plug-in hybrid has a roughly 12,000-unit lead over the EV since the two cars brought plug-in vehicles back to the mass market all the way back in December 2010. We will have our full report of January's green car sales up soon.

Cadillac tops Tesla in Consumer Reports semi-automated driving test

General Motors' Cadillac outscored Tesla in a new ranking of partially automated driving systems tested by Consumer Reports and released on Thursday. The highly influential nonprofit organization, which tests and rates a variety of consumer products from appliances to vehicles, said it compared Cadillac's Super Cruise and Tesla's Autopilot with similar systems from Nissan and Volvo. Nissan's ProPilot Assist was ranked third and Volvo's Pilot Assist fourth. Consumer Reports said it has been testing partially automated driving systems for several years but elected to conduct a formal study intended for publication, because "we are at a tipping point where they are now going mainstream," according to Jake Fisher, director of auto testing. The organization said its tests, conducted on a private track and on public roads in Connecticut, were designed to measure the systems' ability to automatically control steering and speed in certain situations, while helping drivers pay attention and regain manual control of the vehicle when required. CR noted that any of these systems can increase driving risk if used in inappropriate situations, or if drivers become inattentive or over-reliant on them. While they can help relieve driver stress and fatigue, Consumer Reports said, the partially automated systems are "not intended to be self-driving features." The systems typically use cameras, radar and other sensors, as well as mapping data, to monitor location and traffic conditions and help keep a vehicle centered in the lane at a safe distance behind other cars. Each system has limitations. Cadillac's Super Cruise, for instance, only functions on divided highways that have been mapped by GM. In contrast, Tesla's Autopilot can be used even on small, curvy roads with poor lane markings, but "operates erratically in those situations," Consumer Reports said.The organization tested Super Cruise on the Cadillac CT6; Autopilot on the Tesla Model 3, Model X and Model S; ProPilot Assist on the Nissan Leaf and Infiniti QX50; and Pilot Assist on the Volvo XC40 and XC60. Consumer Reports said Cadillac's Super Cruise did "the best job of balancing high-tech capabilities with ensuring the car is operated safely and the driver is paying attention." Tesla's Autopilot was cited for its capability and ease of use, while Nissan's ProPilot Assist did a better job than Autopilot or Volvo's Pilot Assist in keeping drivers engaged.