BMW isn't alone in needing to make its small cars more fuel efficient, and like Ford, which is trying to sell America on its 1.0-liter three-cylinder, Bimmer sees fewer cylinders as part of the solution. The automaker says its 1.5-liter three-cylinder is up to 15 percent more efficient than the current 2.0-liter four, weighs nearly 25 percent less, and is likely to power a number of new models.
BMW says its magic formula is that each cylinder displaces a half liter; that is true for its existing 2.0-liter four-cylinder engines and of course the 3.0-liter in-line sixes. Beyond the mathematical elegance of this is an obvious gain in common dimensions to parts. BMW can also make 1.5-liter three-cylinders diesels on the same assembly line, and when an engine is powered by the same fuel (for instance a three-cylinder diesel and a six-cylinder diesel) there's up to a 60 percent commonality on parts, all of which saves BMW a fortune in parts costs and assembly speed.
The three-cylinder will reside in the back half of BMW's forthcoming i8, when that super-plug-in-hybrid debuts this coming winter. But this mono-scroll, 1.5-liter turbocharged three-cylinder is more than a niche product. BMW also spoke openly of how the engine would work transversely or mounted in-line, which gives the engineers a lot of options. It's an obvious choice for Mini, and BMW all but gave us that. The three-cylinder could go into BMW's 2-series and just about anywhere the company presently uses turbocharged fours.
For our test at the New York Auto Show, BMW showcased the engine on 1-Series prototypes. In the i8 concept cars, BMW says, it makes 223hp. The cars we test-drove (for about 10 minutes) felt like somewhere closer to 180-200 hp.
BMW says that the gas three-liter is happiest, producing between 44 and 66 lb. ft. of torque per cylinder, but a key characteristic of the gas version of this engine is that it pulls hard from idle, with peak torque hitting very low in the curve. In fact, BMW says that peak torque hits quicker than on its turbocharged four-cylinder cars.
Mind you, this was a very brief taste of the engine. And it must be said that first, these were mules, not production models, and second, they were mated to BMW's automated manual gearbox. But the first impression is aural: The low end of the three-cylinder sounds motorcycle raw. Higher up it winds more smoothly, a little like BMW's in-line six, though BMW says it's still working on exhaust tuning. Also, at least in the 1-series, there's lots of ready power but also flexible power. You don't have to flog this motor to get useful output, and that's going to be a huge relief for the-sky-is-falling fans of BMW and Mini.
manu ginobili sports illustrated swimsuit 2012 aretha franklin whitney houston paul williams paul babeu kevin costner budweiser shootout
কোন মন্তব্য নেই:
একটি মন্তব্য পোস্ট করুন