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Ford: 4 cylinders good; 3 cylinders better
The fuel economy race is on, and 50 mpg on the highway is a major goal for automakers around the world. Ford's strategy includes cutting the cylinders to three — a concept not seen frequently in the last decade.
Fri, Jun 03 2011 at 2:58 PM
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CAR MAX: The Fiesta may be part of Ford's upgrade. (Photo courtesy of Ford)
Never ask an engineer anything. I called Bob Fascetti, Ford’s director of global engine engineering, about reports that the company is introducing both three-cylinder EcoBoost engines (with turbocharging, and by 2013) and eight-speed transmissions in an effort, one suspects, to get to 50 mpg on the highway in cars like the Fiesta.
I wrote recently that 40 is the new 30 when it comes to fuel economy. Now 50 is the new 40. Anyway, I asked Fascetti how Ford manages to retain smoothness in a three cylinder engine. The answer was technical and involved something called “fully crennelated crankshafts.” They “make it easier to manage the torque pulses — in an eight, you fire all the cylinders in two crank revolutions. In a three, you have three pulses for revolution and the fully crennelated crankshaft helps you balance it. We also put our engine mounts in the right place, and sometimes use balance shafts.”
I think he said “fully crennelated,” but I may have gotten that wrong. I promise not to look it up if you don’t.
We’re in some really interesting fuel economy wars, with automakers struggling to meet not only increasing consumer demand ($4 a gallon gas will do that) but also Obama administration rules that require cars to reach 35.5 mpg by 2016 (and maybe as much as 60 mpg by 2025). Every automaker is going this route, and even GM — once averse to tech improvements — is now going the eight-speed transmission route.
Fascetti told me that Ford doesn’t actually have the eight-speed boxes yet, but the company is working on it. The eight-speed and the three-cylinder won’t be in the same car, though some media outlets reported it that way. The eight-speed is for larger cars, like the Taurus or Fusion.
Richard Pruett, Ford’s powertrain spokesman, told me that the company now has four cars, the Focus and Fiesta, as well as the Fusion and Lincoln MKZ hybrids, that pass the magic 40 mpg mark. But even that won’t be good enough in the not-too-distant future. The new window stickers will have a ton of fuel economy information on them (though no letter grades), and consumers are going to be looking closely at the numbers — the first one to 50 gets some points.
Fascetti told me that the three cylinder is a “global engine offering that we think will satisfy the customer base around the world.” It will certainly slot into a lot of overseas Ford product, where tiny is the new norm. Chinese and Indian buyers never saw the Ford Excursion, so they never developed a jones for it, or anything else that big.
I’m all for three-cylinder cars, and if a fully crennelated crankshaft is part of the deal, I’m perfectly happy.
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The Metro was doing this years ago. If they can up the overall quality it should work out very well.
Good point about the 50+ mpg Chevy Metro. And Chevy accomplished the astonishing 50+ mpg in early 1990s technology without any "crennalated" crankshaft.
They did this keeping weight under 1700 pounds, 13 inch tires, throttle body injection efficiency. The car was awesome, I hope Ford's new offering will crennalate as well.