2003 Bmw Z4 2.5i Convertible 2-door 2.5l on 2040-cars

Auto blog

As BMW i3 US launch nears, more details discovered

Think of the BMW i3's gas-powered range-extender as akin to driving around with a middle linebacker in the back seat. Except that football player will have a hard time pushing the car 60 miles or so once the battery runs out. Thankfully, he won't prevent you from getting a nifty tax credit either, according to BMWBlog, which isn't affiliated with the company. The i3's front storage compartment is not watertight. Here in the US, where the i3 will be available in short order, BMW will offer an optional i3 plug-in vehicle with a range extender that will have a 1.9-gallon capacity gas tank. That sounds a good deal smaller than the 2.4-gallon tank used in Europe, but the two are actually the same, the US tank is simply limited to the smaller size, Dave Buchko, from BMW's product and technology communications department, told AutoblogGreen. The complete range extender system – including the tank, the engine, and all related hardware – adds about 265 pounds to the 2,634-pound curb weight of the i3 EV and the extra weight in turn adds about a second to the EV's 0-to-60 time of seven seconds flat. Adding the range-extender won't make the US government take any longer to dole out a $7,500 tax credit for the i3, though. We also learned that the i3's front storage compartment is not watertight since it is only meant to hold the mobility kit and the 110-volt charging cord. BMW recently increased its production of the i3 at its German factory from around 70 units a day to about 100 due to better-than-expected demand. Check out our First Drive impressions of the model here.

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 shows off 245-hp, hydrogen-powered 5 Series GT

With BMW's Innovation Days 2015 underway, the German luxury brand is showing off its latest piece of hydrogen-fuel-cell technology. Based in a 5 Series Gran Turismo, the system Í– co-developed with Toyota – promises to deliver on the promise of zero-emissions motoring, without the lengthy recharge times associated with plug-in electric vehicles. At the heart of BMW's latest FCV prototype is a new electric motor derived from the i sub-brand. It produces the equivalent of 245 horsepower, making it roughly comparable in output to the brand's latest 2.0-liter, turbocharged, four-cylinder gas engines. It draws its fuel from a hydrogen fuel tank that sits between the axles. The BMW-patented storage system can hold enough compressed hydrogen to take the hunchbacked 5 Series 300 miles before refueling. BMW and Toyota first inked their FCV partnership back in 2013, with the goal of having "an initial group of approved components ready by 2020," and sales beginning at some point in the next decade. While Toyota has been touting its successes with hydrogen in the form of the new Mirai, this 5 Series marks the first time since the agreement was signed that the German company rolled out one of its hydrogen-powered cars to the public. Check out the 5 Series GT fuel-cell vehicle in the gallery up top, and then scroll down for the official press release from BMW. Long range, short refuelling times, zero emissions: Hydrogen fuel cell drive system points the way to the future of BMW eDrive technology. As part of its research and predevelopment work in the area of drive technology, the BMW Group has focused on the use of hydrogen as an energy source for more than 30 years now. In 2006 the first luxury sedan for everyday use to be powered by a hydrogen combustion engine was unveiled – the BMW Hydrogen 7. And more than 15 years ago the BMW Group also began to direct its spotlight onto hydrogen fuel cell drive systems. A constant stream of significant advances – in terms of energy efficiency, performance capability and everyday practicality – have likewise been made with this technology, which converts hydrogen into power for an electric drive system, rather than burning it inside the engine. The results of the research and development activities in the field of hydrogen fuel cell drive systems will be presented in driving demonstrations for the first time during the BMW Group Innovation Days 2015.