Automotive

Audi introduces new combustion method in latest high-efficiency engine

Audi has developed a new 2.0-liter engine with a revised combustion cycle for its new A4
Audi has developed a new 2.0-liter engine with a revised combustion cycle for its new A4
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Audi has developed a new 2.0-liter engine with a revised combustion cycle for its new A4
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Audi has developed a new 2.0-liter engine with a revised combustion cycle for its new A4

In the face of ever-tightening emissions regulations, the world's car manufacturers are finding innovative ways to cut fuel consumption. In its quest for greater fuel efficiency, Audi has developed a four-cylinder TFSI engine that makes use of a new combustion method, resulting in what Audi claims is the most efficient two-liter gasoline engine in its class.

The combustion method used in Audi's new engine is similar to the Miller cycle, and allows the 2.0-liter turbo unit to produce 140 kW (190 hp), all the while returning a seriously impressive 5.0 L/100km (47 mpg) on the New European Drive Cycle (NEDC). The engine also produces 320 Nm (236 lb-ft) of torque, all of which will be available from just 1,450 rpm, making it perfect for surging into gaps in the traffic from low speeds.

To achieve these figures, Audi has shortened the engine's intake time by taking the crank angle and reducing it from 200 to 140 degrees. Despite the shorter intake time, the engine can still achieve optimal cylinder charges thanks to higher boost pressure on its inlet side. Under the engine's new combustion cycle, the intake valve also closes earlier than it usually would, which allows Audi to run an efficiency-boosting high compression ratio.

"Thanks to this rightsizing approach, the new engine enjoys the consumption benefits of a downsizing engine in partial load operation, while at higher loads it has the advantages of a large-displacement engine," says Stefan Knirsch, Audi's Head of Engine Development. "The result is optimal efficiency and performance characteristics across the entire engine speed range."

The new engine, which is set to debut in the next-generation A4, has also been designed to spend less time in its warm-up phase, and Audi has focused on reducing friction – something Mercedes does with its Nanoslide coating on the inside of its engines.

On top of these efficiency-driven changes to the drive cycle, the new engine is also light, weighing in at just 140 kg (308.6 lb), which should aid the new A4's handling balance as well as its fuel consumption sticker.

The engine was unveiled at the Vienna Motor Symposium, and will be in the new A4 by the end of 2015 before making its way to other model series.

Source: Audi

12 comments
Cyndy
That's wonderful an efficient way to pollute our planet..
Glen Jacobsen
"high compression ratio", does this mean premium gas, which is getting harder and harder to find, and ever more expensive when compared to regular?
jaxx003
Someday that thing will make a good Steampunk artifact. Sooo twentieth century. C'mon Audi.
DonnGross
This is simply finding a less hungry horse. Horses are out and so is the Internal combustion Engine.
65tux
So you all think they shouldn't try to make IC engines more efficient then? I'm all for coming up with a better answer but in the meantime doesn't it make sense to make the only currently viable (for people that don't live inside a city) automotive propulsion method more efficient?
mach37
DonnGross, internal combustion engines are out? Tell that to the auto manufacturers. I don't see hybrids and electric motors replacing IC engines within my lifetime. Cyndy, how does less pollution equate to "no progress" in reducing pollution? Jaxx003, how does progress in the 21st century seem archaic to you? Getting more than twice the MPG as 20th century engines is worth something.
Martin Hone
Um...reduced crank angle to reduce intake time AND closing the intake valve earlier....same thing ?
Simon
I agree with Mach and 65tux. So much of the time on Gizmag comments all we get is bleating, whining negativity. Donn, jaxx etc. it's very ease to criticize the efforts of others, much harder to come up with constructive criticism that would improve the product and even harder still to come up with something yourself. I look forward to the day when you and your ilk grace the pages of Gizmag with something new and innovative so the rest of us can all pile on the what a load of crap comments.
Bill Bennett
Have they done anything about intake valve deposit issues that Direct Injection engines have? It is not free to clean them every 30,000 miles.
BruceHarrison
Notice that none of the negative comments are from people that are actively inventing anything. You type crap on social media, good for you. At least you are not in the way of people making actual progress. Here is a news flash for all of you people living in fantasy land. Truly green tech will come in increments. You wont see 40 MPG and then 1 year later 3000 MPG and then 1 year later 0 fuel/0 emissions. I hate this generation of kids that is so used to instant gratification. The rate at which cars are improving is accelerating, this is a good thing. Have a problem with the pace? Get educated and join the generation of people actually working to improve technology.....or just type crap on social media.