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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.

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.

Diesel-powered 2020 Chevrolet Silverado, GMC Sierra get big price cuts

General Motors is reducing the price difference between its diesel-powered light-duty pickups and their gasoline-burning counterparts, according to a recent report. As of September 3, 2020, the Chevrolet Silverado 1500 and the GMC Sierra 1500 benefit from a $1,500 price cut when they're ordered with a turbodiesel under the hood. Enthusiast website GM Authority first reported the news after looking at internal documents sent to dealers across the nation. It wrote the discount applies to in-stock and in-transit units of the Silverado and the Sierra (pictured), and it added dealers will begin receiving amended window stickers on September 8. And, it's not just a quick, easy way for General Motors stores to clear out 2020 inventory. Incoming 2021 models will benefit from it, too. Chevrolet's cheapest diesel-slurping 2020 Silverado, a double-cab LT with two-wheel drive, now starts at $44,000 once a mandatory $1,595 destination charge enters the equation. For context, the same configuration costs $38,795 including destination when it's ordered with the 2.7-liter turbocharged four-cylinder, which is the smallest and cheapest engine on the roster. Selecting the more efficient engine option costs buyers $5,205. At the other end of the spectrum, the crew-cab High Country with a standard cargo box and four-wheel drive is now priced at $59,690. Walk a block to the GMC store, and you'll need to spend between $44,470 (double-cab SLE with two-wheel drive) and $61,685 (crew-cab Denali with a regular cargo box and four-wheel drive) for a diesel-powered Sierra. It doesn't sound like either company is making major mechanical changes to the trucks for 2021. Both are powered by a 3.0-liter straight-six Duramax engine, which makes 277 horsepower and 460 pound-feet of torque. Rear-wheel drive and a 10-speed automatic transmission come standard, and four-wheel drive is offered at an extra cost. In its most efficient configuration, the Silverado returns 23 mpg in the city, 33 mpg on the highway, and 27 mpg in a mixed cycle, impressive numbers for a body-on-frmae pickup that's as heavy as it is capable. Ram's diesel-powered 1500 posts EPA estimates of 22, 32, and 26, respectively. Ford pledged the recently-unveiled 14th-generation F-150 will offer a turbodiesel engine, too, but its fuel economy figures are not available yet.