Bmw 5-series 528i 535i 550i on 2040-cars

Auto blog

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.

BMW Looks Toward Future with Vision Next 100 Concept | Autoblog Minute

BMW looks to the future, reveals Vision Next 100 concept.

BMW recalling 1 Series ActiveE over bad drivetrain housing

There are always growing pains when automakers introduce new technologies. BMW is learning this with the electric powetrain used on the 2011 BMW ActiveE. According to the National Highway Traffic Safety Administration, about half of the all-electric 1 Series coupes currently in the hands of the public are being recalled for a potential problem that could leave the cars stranded.
With 700 ActiveE models running around the US, 360 of these cars have insufficient sealing between the electric motor and transmission, which could lead to premature wear to the connection between the two, which in turn could result in a loss of propulsion. BMW started notifying affected owners by phone earlier this month.
While no automaker wants a recall on its hands, it's much better for BMW to learn such a lesson now on the low-production, lease-only ActiveE ahead of the car's successor, the BMW i3, which is expected to be a much higher-volume EV. Scroll down for the official recall notification.