2014 Nissan Altima 2.5 on 2040-cars

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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.

NHTSA urges owners of recalled Takata airbag vehicles to take immediate action

The National Highway Traffic Safety Administration and the Department of Transportation are taking the unusual step of issuing a followup press release urging owners of certain recalled vehicles "to act immediately" to fix their cars and trucks. The problem in question concerns the repair campaigns for rupturing Takata airbag inflators issued in June and covers a long list of models from Toyota, Lexus, Honda, Acura, Mazda, BMW, Nissan, Infiniti, Buick, Cadillac, Chevrolet, GMC, Oldsmobile and Pontiac.
While NHSTA doesn't specifically say why the recall is vital in the new release, Toyota's own explanation in its newly announced renotification campaign earlier today sheds some new light on the topic. According to the Japanese automaker, in testing, Takata found a possible link between the rupturing airbag inflators and high humidity. NHTSA is advocating that all owners pursue repairs immediately if they haven't already done so already. This is especially crucial for those drivers especially in Florida, Puerto Rico, Guam, Saipan, American Samoa, Virgin Islands and Hawaii because of the humid conditions there.
We don't need to tell you how dangerous an inadvertent airbag deployment could be - even in a stationary vehicle - but adding to the Takata issue is fears that the deployment could lead to shrapnel being sprayed into the cabin.

Porsche wins the 2015 24 Hours of Le Mans

The question going into this year's 24 Hours of Le Mans was whether or not the Porsche 919 Hybrid would be able to combine its qualifying pace with race reliability. After battling neck-and-neck with Audi's R18 for most of the race, the answer is a resounding yes. Not only did Porsche drivers climb the first two spots on the podium, they did so without any major mishaps on track. This win is the first overall trophy for Porsche since 1998. Audi previously won the last five races, and 13 of the last 15. Corvette also returned to the winner's circle, with the No. 64 C7.R taking winning the GTE Pro division. The victory is the first class win for Corvette since 2011. KCMG won the LMP2 class in ninth overall. With 45 minutes to go the No. 98 Aston Martin crashed out of first place in GTE Amateur, giving the class win to SMP Racing's Ferrari and second place to the Patrick Dempsey Racing Porsche 911 RSR. For the full list of official results, click here. The GTE Pro class proved to be just as exciting as the P1 class, with a four-way battle for first after four hours into the race. For most of the race, the battle at the top went back and forth between the two German manufacturers. An tire puncture in the No. 7 Audi gave up the lead to Porsche, and moments later a crash forced the No. 8 into the garage. But a three-minute replacement of the front and rear bodywork kept the Audi in contention. As the race wore into the night, Porsche maintained a slightly faster pace than Audi. Nick Tandy took the lead on Lap 253 early Sunday morning, and car No. 19 never gave up the top position. The win is the first for all three drivers of the No. 19 – Nico Hulkenberg, Earl Bamber, and Nick Tandy. A lap behind in second was the No. 17 Porsche. The Audis fought reliability problems late in the race but still finished third with the No. 7 R18. The GTE Pro class proved to be just as exciting as the P1 class, with a four-way battle for first after four hours into the race. As the Aston Martin cars dropped away, the lone Corvette Racing entry took over, followed by a charging AF Corse team Ferrari 458 Italia. The Corvette and Ferrari continued to trade places in the final hours until gearbox trouble forced the No. 51 Ferrari out of contention. It was eventually passed by the other AF Corse car, No. 71. Nissan experienced all the pain of a first-year effort with its front-wheel-drive GT-R LM Nismo.