1995 Bmw M3 Coupe 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.

2015 BMW X4 gets its small-screen debut

It's easy to dismiss the 2015 BMW X4. On one hand, the high-style crossover seems more like a boardroom decision than a practical one. In a world with the 3 Series, 4 Series, X3, 3 Series GT and 4 Series Gran Coupe, is BMW really being inundated with requests for a baby X6? Of course, when we finally got behind the wheel of the CUV for our First Drive, it proved rather entertaining, and certainly the X6's global sales success suggests that it's worth the relatively low-cost risk for the Bavarian automaker.
Now, it's the general public's chance to weigh in on the latest crossover Bimmer and vote with their dollars. The X4 is just hitting showrooms in the US, and BMW is beginning its marketing campaign for it with the slogan "Embrace the Unknown." The first TV ad shows off the CUV driving through the world's major cities as they undulate like the rolling ocean. A woman flatly says phrases starting with "Go," while a synth-heavy score plays underneath that wouldn't be out of place over the end credits in an '80s sci-fi movie.
Visually, it's actually kind of a cool ad and evokes some of the special effects from Inception. Focusing on an urban atmosphere is probably a good idea, too, because the percentage of X4s going offroad is likely to be in the low single digits, if that. Now, let's see if BMW buyers are willing to embrace the unknown of the X4. Scroll down to watch it for yourself.

This insane Barris-like custom car is a backyard BMW Z3 build

This is the second car made by Englishman Paul Bacon and it's called the Cosmotron, fashioned over 18 months in his backyard shed. Underneath that Jetsons bubble canopy and swinging-sixties body are the bones of a 1998 BMW Z3 with a 2.8-liter inline-six. Bacon stripped the roadster down, then built it back up using fiberglass laid over polystyrene foam, and leather hand-stitched by his wife. Bacon said he remembers how we were told that 21st-century cars would look like the Cosmotron, and since they don't, he had to fix the error. The list of 20th-century add-ons, however, is impressive, like the six SU carburetors topped off with department-store salt and pepper shakers, and the rear grille decorated with shiny plastic tops from moisturizer bottles. After driving the Cosmotron for two years, Bacon sold it to get ready for his third project. You can hear Bacon and the new buyer tell their stories in the video above.