Mazda Develops Naturally Aspirated Miller-cycle Engine


Mazda is known for its use of rotary engines on their production vehicles. They have gained a lot of success both in the racing world as well as in the global auto market due to their advancements in the development of the Wankel engine. Recently, the Japanese car manufacturer succeeded in developing a naturally-aspirated Miler-cycle engine.

The new MZR 1.3-liter Miller-cycle engine will be used by Mazda to power the new Mazda2 vehicle model. The 2008 model year version of the Mazda2 will be released by July this year. The Miller-cycle engine will be mated with Mazda’s first CVT or continuously variable transmission.

The engine and the new transmission will help the Mazda2 reduce its fuel consumption by as much as 20 percent compared to the current Mazda2. Currently, the Mazda2 has a gas mileage rating of 19.2 kilometers per liter of gasoline. With the new naturally-aspirated Miller-cycle engine, the Mazda2 can cover 23 kilometers on a single liter of gasoline. That can be achieved even without the help of aftermarket parts like the Airaid cold air intake system.

The Miller-cycle engine uses a “fifth” cycle to reduce the power loss in the compression stroke of the engine. This is done by opening the intake valve longer while a supercharger provides low compression. The disadvantage, of course, is that the supercharger gets its power from the engine thereby deducting a certain portion of its power output. With the naturally-aspirated Miller-cycle engine, the use of supercharger is eliminated while still providing a good power output.

The opening and closing of Mazda’s Miller-cycle engine is facilitated by the Sequential Valve Timing System that was developed for the said engine. Fuel efficiency is given a boost on cruising and acceleration. The fuel efficiency of the engine is complemented by the fuel saving ability of the CVT. The continuously variable transmission not only offers good fuel economy but also smooth gear changes which makes a ride on a Mazda2 equipped with this auto part quite comfortable.

Aside from giving the Mazda2 a new engine and the company’s first CVT, it is also made lighter compared to its predecessors. The new Mazda2 is 100 kilograms lighter than the current Mazda2 – or the Demio as it is called in Japan. The lighter Mazda2 means that it handles better than its predecessor. The lighter weight also means less power that it needs to power it forward. That translates to more fuel savings.

The combination of the engine and the continuously variable transmission also makes the car an environment-friendly one. According to tests conducted on the new Mazda2, greenhouse gas emission is 75 percent lower than the set standard. The exhaust emission of the Mazda2 makes it meet Japan’s Super Ultra-Low Emissions Vehicle standard. That means that the car qualifies for the Green Tax exemptions which are a tax incentive for those who will purchase proven environment-friendly vehicles.

The development of the naturally-aspirated Miller-cycle engine is part of Mazda’s Zoom-Zoom plan. Through the strategy, Mazda aims to combine driving pleasure with environmental and safety features, just like what the company did with the new Mazda2.


Source by Mike Bartley