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2015 BMW M4 Convertible is here to put wind in your sails

Each generation of the BMW M3 has included a convertible model. Even the distant E30, the patriarch of the M3 line, had an ultra-rare (only 787 were built) droptop model. The convertible became more common on the successive generations, with the hardtop-convertible E93 being the most recent. Considering this history, there seemed very little doubt that as the M3 became the M4, a convertible would be in the cards. Now, the new droptop has arrived.
Set for its global debut at the 2014 New York Auto Show, the 2015 BMW M4 Convertible features, like its forbearers, everything that's great about the hardtop variant while adding an unlimited amount of head room. That means the same 3.0-liter, 425-horsepower, 406-pound-foot, twin-turbocharged straight six sits under its domed hood, while either a six-speed stick or a seven-speed M dual-clutch transmission dispatches power to the fat rear tires.
As for specific differences between the hardtop and the new convertible, obviously, the droptop is heavier. A lot heavier. Where an M4 with a six-speed manual tips the scales at 3,530 pounds, the M4 Convertible weighs in at 4,055 pounds. Believe it or not, BMW has actually trimmed 90 pounds from the last-generation M3 convertible, code-named E93. This marginal weight reduction from the third-generation convertible to the fourth is barely half of the 174 pounds BMW was able to subtract when transitioning from M3 Coupe to M4 Coupe.

BMW 1 Series prototype packs direct water injection

Just a few months ago, BMW showcased an M4 that was modified to serve as the safety car for the MotoGP racing series. The flashing lights and emergency equipment, however, weren't the only modifications BMW made to the performance coupe. It also packed an innovative new water injection system. And now it's furthering the development of that system by running it in a 1 Series hatchback as well. Revealed at the BMW Group Innovation Days 2015 event, this five-door 1 Series packs a three-cylinder gasoline engine – like the one found in a Mini or i8 – but fitted with the direct water injection system. In this application, the system sprays a fine mist of water – yep, regular old H2O – right into the combustion chamber. While mixing water with gasoline normally wouldn't be recommended, in this case it evaporates immediately and helps cool the engine from the inside, allowing it to run at higher efficiency. That cooler running engine brings with it several benefits. It delivers improved fuel economy and lower emissions, to start. It also allows for an earlier ignition point, higher compression ratio, and higher boost pressure in turbocharged engines, delivering increased output. It even cuts down on engine knocking (where combustion occurs spontaneously), reduces wear and tear on the engine, and makes better use of lower octane levels. If that sounds like a win-win-win... win (we're losing count of all the wins here), it's because BMW just may be on to something. Of course it does require a water tank to be fitted on board, which means added weight, but instead of requiring the driver fill up the water tank, BMW has fitted this prototype with a system that replenishes the water level from the air conditioning system when the vehicle is switched off. So unless it's being driven in a particularly extreme climate, it doesn't even need topping up. Add one more "win" to the list, then. Extra power, improved real-world fuel economy: Direct water injection enhances efficiency. With direct water injection for turbocharged petrol engines, the BMW Group has again succeeded in enhancing the capabilities of conventional engine technology through an ongoing process of refinement and improvement. The precisely controlled injection of water into the engine cylinders produces a cooling effect that boosts power and torque, particularly when operating at or near full throttle, while at the same time reducing fuel consumption and emissions.

Comparison test: 2019 Acura RDX vs. compact luxury SUV competitors

Truth be told, if we were to compare the all-new 2019 Acura RDX with those compact luxury crossover SUVs it would most likely be cross-shopped against, you'd be looking at a different list. Even Acura admits that Lexus and Infiniti are the most likely bogies, but with the 2019 RDX, Honda's luxury brand is attempting to attract those customers who think as much with their hearts as with their heads. And for the most part, those folks have been buying from German brands: the Audi Q5, BMW X3 and Mercedes-Benz GLC-Class. So, to show how the new RDX compares to them, Acura actually provided examples of each during the recent press drive along with a Volvo XC60. All were determined to have greater emotional appeal than the last RDX, and we would certainly agree. For, as much as the previous-generation RDX made sense on paper, it was really hard to get excited about it. And when you're paying extra for a luxury vehicle, shouldn't you get a little excited? Well, as luck would have it, Consumer Editor Jeremy Korzeniewski and I were on hand in Whistler, British Columbia, for the press launch. We didn't have an abundance of time in each RDX competitor, but in conjunction with our usual comparison chart, our impressions should provide a good first taste of how the new RDX compares. Performance and fuel economy Contributing Editor James Riswick: On paper at least, the RDX is gutsier than its comparably powered European rivals. It also weighs the same or less, which logically should mean it'll be the quickest in a straight line. During my brief drives, though, I'm not sure it really stood taller than the three Germans. It at least matches them for smoothness, which is something that can't be said about the Volvo. Fuel economy is lower than them all when you consider all but the Mercedes come standard with all-wheel drive. It's also worth noting that all the competitors are available with engine upgrades, and unless Acura's forthcoming resurrection of Type S models includes the RDX, it should stay that way. Consumer Editor Jeremy Korzeniewski: Line 'em all up in a drag race, and I have a feeling the Acura would squirt away to victory. A good bit of that, though, would be due to its 10-speed automatic transmission, which offers a huge spread of ratios and fires off extremely quick shifts. In the real world, I'd guess fuel economy will be similar across the board, so I'm willing to call that category a draw.