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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.

Weekly Recap: Autonomous driving goes commercial in Nevada

Nevada granted Daimler Trucks North America the first license to run an autonomous commercial vehicle on public roads in the United States Tuesday, marking another milestone in the technology's rapid advancement. Gov. Brian Sandoval and Daimler truck chief Wolfgang Bernhard promptly used the license to lap Highway 15 near Las Vegas in a newly revealed Freightliner Inspiration Truck. It was a clear signal that autonomous driving is big-rig reality, though it's still a long way from widespread use. Nevada certified two of Daimler's Freightliner Inspiration Trucks, which use the company's Highway Pilot system with a stereo camera, radar, and lane-keeping collision-prevention features to regulate the brakes and steering. The radar component has a long-range sensor that can cover 820 feet at an 18-degree angle and a shorter-range unit that stretches 230 feet at a 130-degree angle. The Inspiration trucks are based on the existing Freightliner Cascadia Evolution model used on US roads. In addition to the autonomous technologies, it also has futuristic design cues, including blue lighting in the front and a new hood and grille. While there are only two Freightliner Inspiration trucks in existence, Daimler expects to bring the Highway Pilot system into mass-produced big rigs by 2025, in time to capitalize on the market's predicted growth. The German truckmaker predicts the global hauling market will triple by 2050, and the United States will be a key part of that growth. Trucks carry 69.1 percent the nation's domestic freight tonnage and hauled 9.7 billion tons of freight in 2013, according to the American Trucking Association. Daimler expects autonomous driving to augment this growth, and perhaps evolve the role of the truck driver. Still, the company points out autonomous tech is not meant to replace drivers, but to assist them and relieve fatigue and monotony on long hauls. The driver has to stay in control for passing, in city traffic, and when hooking up the trailer. The company said autonomous driving also offers the potential for improved fuel economy – tests showed a five-percent gain – and lower maintenance costs. Daimler also said the technology could reduce congestion on the road. Much of this is attributable to the constant flow of traffic, which is aided by autonomous driving. While the benefits are becoming increasingly apparent, autonomous technology is still met with skepticism.

Nissan Leaf makes it 19 in a row for record sales; Chevy Volt drops 21 percent

The Nissan Leaf continues its streak of "best month ever" sales with 2,881 EVs sold in September. Compared to the 1,953 sold in September 2013, that represents an increase of 47.5 percent and, as Nissan itself must be tired of saying by now, it marks yet another best month ever, same as last month and now the 19th in a row. Okay, sure, we know, Nissan will tout this run for as long as it can, but we're certainly expecting it each month, so if it ever doesn't happen, it'll be interesting to see how Nissan talks about it. Year-to-date, Leaf sales are up 35.7 percent compared to 2013. In any case, Nissan's director of EV marketing, Toby Perry, sent AutoblogGreen a statement that said, "Nissan Leaf owners have turned into some of our best marketers, and they jump at any opportunity to share their enthusiasm with friends and family. Take National Drive Electric Week – a grassroots celebration of all things EV and the perfect platform for LEAF owners to showcase the benefits of going electric. After celebrating with EV owners in more than 130 cities across the country, we saw a significant increase in Leaf showroom visits with midweek traffic just as heavy as what we see on the weekends." Year-to-date, Leaf sales are up 35.7 percent compared to 2013. Over on the Chevy Volt front, things aren't quite as rosy. After coming off a good August (the best sales month of 2014 by almost 500 units), Volt sales were down to 1,394, a decrease of 21.1 percent compared to September 2013. So far this year, Volt sales are down 13.2 percent year-over-year. It's kind of a stretch, but perhaps people are already waiting for the next-gen Volt, which will be revealed at the Detroit Auto Show in January, to go on sale? Speaking of things we say every month, our in-depth round-up of US green car sales is in process and will be appearing soon. Until then, please discuss how these two long-standing plug-in champs are doing on the sales floor. Green Chevrolet Nissan Electric Hybrid PHEV ev sales hybrid sales