Toyota introduces a new range of fuel-efficient engines

Toyota 1.0-liter gasoline engine
Toyota 1.0-liter gasoline engine

Promises to improve fuel efficiency by up to 30 percent

Toyota has unveiled a new range of fuel-efficient engines that promise to achieve fuel efficiency improvements of at least 10 percent over current vehicles.

One of the engines is a newly-developed 1.3-liter petrol that runs on the Atkinson cycle which is typically associated with hybrid engines. As Toyota explains, "Use of the Atkinson cycle provides an increased expansion ratio and reduces waste heat through a high compression ratio (13.5), resulting in superior thermal efficiency." The engine has also been equipped with a distinctive intake port that creates a strong tumble flow - a vertical swirl of the air-fuel mixture - inside the cylinder. This and other innovations should enable the engine to be about 15 percent more fuel efficient than current models.

The company also unveiled a 1.0-liter engine that was jointly-developed with Daihatsu. It eschews the Atkinson cycle but has a similar tumble flow-generating intake port, a cooled EGR system and a high compression ratio. When combined with a start/stop system and "various other fuel consumption reduction technologies," the engine can be up to 30 percent more fuel-efficient than current models.

The engines will be used in several upcoming models and Toyota says we can expect a total of 14 new engine variations to be introduced by 2015.

Source: Toyota

Toyota Develops Engines with Improved Thermal, Fuel Efficiency

Toyota City, Japan, April 10, 2014?Toyota Motor Corporation aims to further increase the environmental performance of its vehicles with a series of newly-developed, highly fuel-efficient engines that achieve outstanding thermal efficiency1. The new engines leverage combustion and loss-reduction technologies Toyota has refined in its dedicated hybrid engines, and will achieve fuel efficiency improvements of at least 10 percent2 over current vehicles. The engines will be used in models scheduled for partial redesign in the near future, and a total of 14 new engine variations will be introduced globally by 2015.

One of the engines is a 1.3-liter gasoline engine in which Toyota is employing the Atkinson cycle3?normally used in dedicated hybrid engines. Use of the Atkinson cycle provides an increased expansion ratio and reduces waste heat through a high compression ratio (13.5), resulting in superior thermal efficiency. Toyota aims to further improve the fuel efficiency of the engine by utilizing other innovations including an intake port with a new shape that generates a strong tumble flow (whereby the air-fuel mixture flows in a vertical swirl) inside the cylinder, and a cooled exhaust gas recirculation (EGR) system paired with Variable Valve Timing-intelligent Electric (VVT-iE) technology to improve combustion and reduce loss. As a result, the new engine will have a maximum thermal efficiency of 38 percent4?top-level among mass-produced engines. The new features, combined with idling stop and other functions, will lead to fuel efficiency gains of approximately 15 percent2 by comparison with current vehicles.

Meanwhile, a 1.0-liter engine jointly developed with Daihatsu Motor Co., Ltd. has achieved maximum thermal efficiency of 37 percent4 due to a similar tumble flow-generating intake port, a cooled EGR system, and a high compression ratio. Combination with the idling-stop function and various other fuel consumption reduction technologies allows vehicles to achieve a maximum fuel efficiency improvement of approximately 30 percent2 over current vehicles.

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Comments (12)

Sacto8780 Sacto8780
These engines are aimed primarily for smaller Toyota vehicles and are likely not make it to any US model Toyota for now. Now, a larger 1.5 to 1.7 liter I-4 with the Atkinson technology could end up on the US-market Yaris model, though.
Apr 11th, 2014 6:21am
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Han Solo Han Solo
I thought they were going beltless, I mean why not electrify the Ancilliary stuff???
Apr 11th, 2014 5:21am
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tomi.ro tomi.ro
I have a problem with that high compression ratio. This forces for high octane petrol to be used. Not I, but the owners that will buy them and use regular petrol. Depends on where in the world they intend on introducing these engines.
Apr 10th, 2014 10:14pm
1 1
Not true. This is similar in concept to Mazda and the skyactiv engines with their very high compression. They have 12.5 or 13.5 (can't remember exactly) on these engines found in the 3 the 6 and CX-5 and they do NOT require premium fuel. I sold mazdas and can tell you they recommend regular fuel and run perfect on it. They also get the mileage they say and better actually as I can promise you first hand. Do some more research sometimes before posting.
Apr 11th, 2014 12:42am
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tomi.ro tomi.ro
Detonation, means anything to you. Especially when you go 13:1. Also, selling cars does not necessarily confirm one's knowledge about the cars he/she is selling or about engineering at all. In fact the vast majority of sales people don't know their facts straight. ;) Don't know you, but your argument is invalid. We could get into technical stuff here, so please don't be smug with your remarks and "manufacturer declaration of conformity". Those are overstated ideas with so many recalls in the auto industry.
Apr 11th, 2014 2:06am
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benz_man benz_man
Alpine6speed is right. Mazda negates the use of premium fuel in its high-comp (13:1) skyactiv engines by having EXTREMELY efficient pumping of the A/F into and out of the cylinders. The inlet swirl, piston design and DI coupled with LONG 4-2-1 exhaust headers do the trick. The downside is the dependency on those items staying exact. A significant loss of driveability, efficiency and power as the engine ages and carbon/blow-by/EGR residue builds up in the intake tract and on the valves is the end result.
Apr 11th, 2014 3:59pm
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tomi.ro tomi.ro
@benz_man I didn't argue the Mazda system. I knew about it. Well, anyone interested can find info about their approach on high CR on their site. But the problem is like you said. Dependency. Read my initial post. Depending on region. There are so many factors that only in real life can occur, paper engineering being a very nice, but theoretical aspect. And we see how manufacturers tend to care for their customer's needs. Some of them ignore problems completely, but most of the times recalls are barely acceptable and when heavy pressure is being put, not to ruin their business....PS: I am a professional buyer.
Apr 12th, 2014 5:42pm
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ScottCampbell ScottCampbell
Hopefully lighter cars will make less horsepower work well in cars. If you limited the top speed of cars to say 100 mph you could gear the car where a smaller engine would definitely be beneficial.
Apr 10th, 2014 9:11pm
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ZHPRegistryNet ZHPRegistryNet
I am surprised how long it's taking to get to camless engines. Pneumatic valves offer a great number of fuel saving features with less mechanical complexity. To me a blower + camless values = perfect... make it a diesel you got yourself an engine that blows electrics out of the water.
Apr 10th, 2014 7:41pm
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HermanCampbell HermanCampbell
Not sure how I feel about the use of Atkinson Cycle motors on non hybrids. They dont seem to produce that much power. They said before though they are going this direction instead of smaller turbo motors. I'll stick with my turbos.
Apr 10th, 2014 6:51pm
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tomi.ro tomi.ro
They drink less fuel, lower pollution and of course, we can't get away from, lower engine output :))
Apr 10th, 2014 10:10pm
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HermanCampbell HermanCampbell
This is true. I guess this is another reason to stay away from Toyota. From the time I got my S60 T5 I've been addicted to turbo power, the torque and thrust are just great lol.
Apr 10th, 2014 11:24pm
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