Turbocharging isn't really Toyota's specialty, and the Japanese automaker isn't being shy about acknowledging it. Koei Saga, a senior managing officer in charge of drivetrain research and development, says that eschewing turbos and increasing displacement of engines using the Atkinson cycle can produce better power gains without sacrificing fuel economy, Automotive News reports.

Toyota is investing heavily in larger-displacement Atkinson-cycle engines in addition to turbocharged engines, but Saga doesn't think the automaker will use turbocharging across many product lines. He apparently remains unconvinced that the technology "makes the world better."

In Toyota's eyes then, Atkinson cycle engines do make the world better, and here's how. By keeping the intake valves open longer, they effectively reduce the length of the compression stroke, cutting pumping losses. The result is greater efficiency at the expense of some torque. This works really well when paired with a hybrid system where the electric motor can provide plenty of torque from very low rpm. Even in a non-hybrid a larger-displacement Atkinson cycle engine could produce a net benefit in efficiency while restoring the torque and power without the weight and cost of the hybrid.

In addition to the aforementioned technologies, Toyota is also investing more in continuously variable and fixed-gear automatic transmissions, as well as its fuel-cell vehicle program. As for electric vehicles? Saga is skeptical of them, stating that Toyota wouldn't have developed the RAV4 EV if it weren't forced to comply with California Air Resource Board regulations. Ouch.

*UPDATE: The paragraph describing the Atkinson engines has been corrected.


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  • 71 Comments
      C4RBON
      • 1 Year Ago
      The Atkinson Cycle engines used by Toyota do not "complete four processes - intake, compression, power and exhaust - in one revolution of the crankshaft." The only way they differ from a normal Otto Cycle is that the intake valve is kept open during a portion of the compression stroke. This is explained in the link to the Autoblog Green article, and in the Wikipedia article that was no doubt read by the author. The way this article is written you would think Toyota is doing something radically different with their engines. They are not. Ford uses the same technique on their hybrids.
      Rotation
      • 1 Year Ago
      Toyota doesn't make real Atkinson cycle engines and they never will. They make Ottos with valvetrain adjustments to change the effective length of the intake stroke. I think there is plenty of room to consider options other than turbos. Especially on small engines, the additional stuff required to add a turbo and intercooler is so relatively large and costly that just making an engine have slightly more displacement (or more revs) becomes a very attractive proposition.
      Spartan
      • 1 Year Ago
      If and only if they can avoid the displacement taxes in some countries, I think this could work. Wasn't that one of the other reasons why so many manufacturers were going the forced induction route?
      Scooter
      • 1 Year Ago
      Toyota owes it current success to a time when cars started falling apart around 100,000 miles, while many Toyota's ran strong. My drove her Toyota Tercel until the wheels literally fell off. (It was totaled in an accident). She always told me the car was really good, ran strong and never had an issue. She drove the car all day long so I tend to believe her. ...But today's automobiles will last to 200,000miles with much less maintenance. Toyota's probably won't outlast most cars today, but it still enjoys success based off of its history of long-running vehicles. With that said, Toyota can also enjoy the benefits of a more liberal business agenda. It can publicly shun EV's and still make record profits. It can venture into expensive fuel cell territory with ease. It can bypass the revolution of turbos and still sell record amounts of cars and trucks. As long as it gives the middle class a new Camry and Corolla every so often, it can pretty write its own ticket.
      mitytitywhitey
      • 1 Year Ago
      I think Mazda is on the right track with their project to replicate the efficiency of compression-ignition with the cheaper fuel petrol. However, a petrol powered diesel-cycle would likely benefit from Toyota's kryptonite- turbocharging
      Scott
      • 1 Year Ago
      They need to do something. It feels as if their engine & powertrain development is years behind the domestic and German automakers.
        marv.shocker
        • 1 Year Ago
        @Scott
        Riiiight. That's why Toyota is on its THIRD GENERATION hybrid powertrain, while the Germans are only just figuring it out and Ford is the only domestic that even has a real hybrid...even though it doesn't get the mileage they claim.
      1guyin10
      • 1 Year Ago
      Its not too surpising that Toyota isn\'t diving into EVs yet. The market just isn\'t there yet so their research dollars are better spent in other places. They would much rather sell 60,000 hybrids at a profit than a few thousand electrics at a large loss. Like most manufacturers they will wait and see on that one. Meanwhile their work on hybrids means they have the engineering talent to jump into EVs if they see some real growth there.
      dukeisduke
      • 1 Year Ago
      That's fine as long as they can meet fuel economy targets. Also, is Toyota not sold on turbo engines and longevity?
      Kampfire
      • 1 Year Ago
      I agree with this. I think the turbocharging trend is due to the EPA cycle biasing the results towards off boost driving. In reality drivers with turbocharged engines will get worse gas mileage compared to a NA engine.
        John
        • 1 Year Ago
        @Kampfire
        I personally get better mileage on my turbocharged car than what the EPA has it listed as. It's all in how you drive. My driving is actually mostly through the hills of the Ohio Amish country.
          AcidTonic
          • 1 Year Ago
          @John
          Same here.... Rated 17/23 but I have no problem get 25-28mpg highway by simply staying out of boost.
        linuxaddict7
        • 1 Year Ago
        @Kampfire
        The EPA needs to adjust driving pattern accordingly so that the tests include usage of turbo as well. Otherwise, the EPA can easily tricked without spooling which of course boosts the EPA economy, but not real life.
      jz78817
      • 1 Year Ago
      Unless Toyota is planning on using true Atkinson-cycle engines (like so: http://www.animatedengines.com/atkinson.html ) then there is a huge fundamental error in this article. The "atkinson cycle" used in hybrids today is really just an approximation. It's just a delayed closing of the intake valve during the compression stroke. A true Atkinson engine has a mechanically shorter compression stroke compared to the power stroke. So no, current Toyota "atkinson" engines still need two crank revolutions to complete a cycle.
      rhb2012
      • 1 Year Ago
      Toyota considers closing the intake valve really late LIVC, an Atkinson cycle. It is simply not true. They are using an Otto cycle, and playing with valve timing. /The end.
      Turbo_S60
      • 1 Year Ago
      Turbos aren't their thing???? Um Supra, MR2, Celica All-Trac three of the best cars Toyota has ever made n they are all turbo!!!!! Hell even the Vitz RS was turbo. Come on Toyota, sack up!
        JDubbs115
        • 1 Year Ago
        @Turbo_S60
        Good point, but weren't all those like 10-20 years ago? Who knows, all those engineers may have (probably) jumped ship since then.
          • 1 Year Ago
          @JDubbs115
          [blocked]
          mitytitywhitey
          • 1 Year Ago
          @JDubbs115
          @carguy -entire range of turbodiesels. I'm sure they have the know-how to build a gasser again.
        mitytitywhitey
        • 1 Year Ago
        @Turbo_S60
        Most truthful.
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