2013 Chevrolet Express Passenger Rwd 2500 135" Lt on 2040-cars

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GM recalls 638,000 U.S. SUVs, trucks for unintended braking

WASHINGTON — General Motors is recalling 638,000 U.S. sport utility vehicles and pickup trucks because a wheel-speed sensor could fail and cause unintended braking, it said Thursday. The recall covers 2015-2020 Chevrolet Suburban, Tahoe, and Yukon and 2014-2018 Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles equipped with a 5.3-liter engine, a 3.08-ratio rear axle and four-wheel drive. The sensor failure could result in unintended activation of the driveline protection system, and cause unintended braking of the wheel on the opposite side of the failed sensor. That could cause the vehicle to pull to one side unexpectedly, increasing the risk of a crash, the Detroit automaker said. GM said it was not aware of any crashes relating to the issue but found 150 field claims alleging the condition caused unintended braking or lateral vehicle motion. A GM dealer in May submitted a warranty report relating to the issue in a 2018 GMC Yukon, and two days later, a GM brand quality manager submitted the report to GMÂ’s Speak Up For Safety program that tracks potential safety issues, which prompted a GM investigation and testing. Recalls Chevrolet GM GMC Truck SUV

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.

Autonomous tech will drive motorheads off the road

While autonomous technology could make car travel much safer and more efficient — and automakers and marketers are salivating over the prospect of a "passenger economy" that could potentially generate $7 trillion by 2050 — those of us who enjoy driving are not so stoked. Experts have predicted that as autonomous vehicles are deployed in large numbers, human-driven cars eventually could be outlawed on public roads due to the carnage they create, which is currently more than 41,000 deaths a year in the U.S. alone and climbing. Such scenarios have driving enthusiasts envisioning a "Red Barchetta" style nightmare becoming reality, making Rush lyricist Neil Peart a clairvoyant as well as one of rock's most badass skin-pounders. But there could be a couple of refuges left for motorheads, and they won't be on public roads. As Popular Science's Joe Brown points out in a recent editorial, we're seeing a wave of vehicles being offered by legit mainstream automakers that aren't made for public roads. The poster child of this vanguard is the 2018 Dodge Challenger SRT Demon, which comes with a crate full of goodies that lets you turn the already formidable street-legal muscle car into a drag-strip dominator. Brown also notes that two out of five of the Ford GT's driving modes are for use on the track, "catering to the $450,000 machine's club-racing clientele." We're also currently enjoying the heyday of production off-road-ready pickups that kicked off with the Ford Raptor in 2009. The latest salvo in this escalating war of overachieving trucks is the Chevy Colorado ZR2 that can take on the likes of California's Rubicon Trail without issue. Brown also gives a shout-out to his magazine's Grand Award Winner, the Alta Motors Redshift MX, which "isn't even allowed on public roads" and is "meant for bombing around motocross tracks, big backyards and single-track woods trails." If you follow Brown on Instagram, you know that he's also a two-wheel aficionado, and he points out that sales of off-road bikes are leaving street machines in the dust. Sales of off-highway motorcycles rose 29 percent between 2012 and 2016, according to the ­Motorcycle Industry Council — compared to 6 percent for road-bike sales during the same period. "That's a nearly 400-percent drubbing," Brown remarks.