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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.

2016 Chevy Volt will have more EV range, bigger battery

Meet the new Volt, not the same as the old Volt. That appears to be the story when General Motors introduces the 2016 Chevy Volt at the Detroit Auto Show in January. Today we're getting some more details on the guts of the new plug-in hybrid, and it turns out they're going to be much improved from the current Volt, which first went on sale at the end of 2010. Sure, the first-gen Volt did get some improvements along the way (a slightly larger battery pack, lane departure warnings) but the new Volt – which will go on sale in the second half of 2015 – marks the first time GM has been able to return to the drawing board and really make the improvements that its customers want. That's how Larry Nitz, GM's executive director of vehicle electrification explained it to AutoblogGreen today when explaining the all-new Voltec extended range electric vehicle (EREV) powertrain. "In the Gen 2 is we gave the engine a little more power, a little more torque, a little more displacement, more capability." – Larry Nitz Nitz said that the new Volt will be better in almost every sense: a bigger battery, longer EV-only range, 20 percent better acceleration in the low speed range and higher overall efficiency. This is due, in part, to the Volt's two motors being able to both act as generators and power the car. As we noted this morning, the 2016 Volt will use a larger, 1.5-liter four-cylinder engine, a version of which is already used in the Chinese-market Cruze. Nitz said that this has a number of benefits, including more power and quieter operation. "Some people would say, why did you make [the first-gen engine] so big. I would say, why did you make it so small?" he said. "It works good, our customers love it, but the reality is that if you go a little bit off and use the car a little harder, you can get the engine to need to operate at a higher speed. In an EV, that's quite noticeable. So, what we did in the Gen 2 is we gave the engine a little more power, a little more torque, a little more displacement, more capability and what it has marginally enabled is not only is it more efficient but it's also quieter." Nitz wouldn't talk about how the new powertrain might affect the two other products that use the Volt's underpinnings – the Cadillac ELR and the Opel Ampera – but if you've got a quieter option, we assume that's something ELR drivers would enjoy. But that's a story for another day.

GM Recalling Another 2.7 Million Vehicles In Five Separate Campaigns

The recalls keep rolling in from General Motors, evidently keen to avoid repeating the mistakes of the ignition-switch debacle and clean house. This time they're all coming at once, with five separate recalls announced together covering approximately 2.7 million vehicles. The largest of the five actions involves over 2.4 million units of the previous-generation Chevrolet Malibu and Malibu Maxx, Pontiac G6 and Saturn Aura in order to fix brake light wiring harness, which have been found to be susceptible to corrosion. The recall is separate from the 56k Aura sedans which GM recently recalled over faulty shift cables, not to mention the previous massive recall of 1.3 million vehicles – some of them the same models – but appears to have resulted from the National Highway Traffic Safety Administration investigation that started with the G6 almost a year ago. The second-largest campaign involves the 2014 Chevy Malibu, specifically those fitted with GM's 2.5-liter engine and stop/start system, approximately 140,000 examples of which has been found to have problematic brakes. The issue does not appear to be connected to the recall of 8k Malibu and Buick LaCrosse sedans (also involving brake woes) which we reported upon last week. Four crashes have been reported in such models, but GM admits it's not yet clear if the problem was a contributing factor in the accidents. A further 112k Corvette models from the 2005-2007 model years are being called in for problems with their low-beam headlamps resulting from a flexing relay control circuit wire that's not meant to bend. GM says it is "aware of several hundred complaints" about this issue, but notes that there have been no reports of related accidents. In addition, over 19k examples of Cadillac CTS from the 2013 and 2014 model years are being recalled over windshield wipers that might not work after a jump start. Finally, GM is also bringing in 477 examples of its 2014 Chevy Silverado, Tahoe and GMC Sierra (though not the Yukon) to fix a problem with a tie rod in its steering rack. As ever, all recall repairs will be performed free of charge, and GM is now estimating that recall-related actions this quarter will result in an estimated $200-million charge against its second-quarter earnings. Read the full announcement from GM below for further details.