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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.

GMC Envoy could be returning as GM files for 'Envoy' trademark

The GMC Envoy could be on its way back, if a recent GM trademark filing is any indication of the future. To be exact, GM's trademark filing is for the name "Envoy," and is applicable to "motor vehicles, namely, sport utility vehicles, engines therefor and structural parts thereof." A victim of the recession and high gas prices, the original Envoy – related to the Blazer, and more recently the TrailBlazer and similar GM SUVs – was discontinued after the 2009 model year. In today's SUV-happy market of low gas prices, unearthing the somewhat familiar Envoy name makes a certain amount of sense. As soon as gas prices start trending in the other direction, we'll all be saying the opposite, though. What this SUV will take shape as is the big question now. With the Chevrolet Blazer well and truly on its way, there's every reason for a GMC version of Chevy's stylish new crossover sporting the Envoy name. Another, less likely, possibility is a Traverse-sized vehicle to slot between the shorter Acadia (10 inches shorter than the Chevy Traverse) and the body-on-frame Yukon. GM could come out of left field and make the Envoy a Buick too. It fits the bill with the "En" beginning, and Buick undoubtedly has crossovers in the works. We think that's even more unlikely, but it's important to remember that we're still in the speculation phase. Soon we'll drive Chevy's new Blazer, and perhaps have more news then. Check in next week for that. Related video:

2015 Chevy Tahoe gets Police Patrol Vehicle treatment

That was fast. Mere days after showing a Police Concept based on the 2015 Tahoe at the SEMA Show, Chevrolet has announced that it will build a PPV model based on the SUV to do battle with the Ford Police Interceptor Utility (Explorer) and Dodge Durango Special Service.
You'll recall that the Tahoe has been police staple for several years, predating both the Explorer and Durango police variants, so the fact that the new model would spawn a police variant is hardly surprising. Like the civilian model, the 2015 PPV benefits from a more efficient 5.3-liter, direct-injection V8 that pumps out 355 horsepower and 383 pound-feet of torque. It also features more high-strength steel, offering better crash protection, on top of optional safety items like lane departure warning, forward collision alert and a Safety Alert Seat.
The press release is rather light on police-specific items, aside from the auxiliary battery, which keeps the myriad of electronics in a modern police car running even when the engine isn't. Lightbars, 17-inch steel wheels on Goodyear Eagle RS-A tires and a push bar round out the mods for the Tahoe PPV. The cabin features a revised center console and room for laptop and other equipment mounts.