2014 Mazda Mazda3 I Sport on 2040-cars

Auto blog

Mazda's next-gen SkyActiv engines will drop spark plugs in favor of high compression

Homogeneous charge compression ignition, or HCCI, is the black art of internal combustion engines that aims to produce diesel-like fuel efficiency for the cost of gasoline. Although some of its competitors have developed and subsequently given up on the tech, Mazda confirmed that the next-generation of SkyActiv engines will employ HCCI technology, improving fuel economy by 30 percent and at the same time reducing exhaust emissions. According to Nikkei, a new SkyActiv family of engines is set to debut under the hood of the next-gen Mazda3 sometime in 2018 before making its way into other vehicles. In simple terms, an engine that uses HCCI burns the air/fuel mix using pressure instead of with spark plugs, just like a diesel. At 14:1, Mazda's gasoline engines already have some of the highest compression ratios out there, but a move to HCCI means cranking up the compression to 18:1. While the tech sounds relatively straightforward, using HCCI means dealing with a number of side issues. It's one of those "on paper" ideas that compounds problems when put into practice. Heat, revs, and fuel must all be carefully managed as gasoline doesn't burn the same way as diesel. Mazda is mum on details, but the automaker seems confident that the issues have been sorted. If the new engines do indeed make it to market with HCCI, Mazda will have out-engineered GM, Daimler, and Hyundai, all of which have tried and failed to develop HCCI engines in a cost-effective package. With the market moving towards electrification, it's interesting to see Mazda still focusing so heavily on traditional internal combustion gasoline engines. It's an indication of where they see the market heading for the next few years. Although the automaker has been hesitant to move forward with hybrid and electric powertrains, Nikkei also reports that Mazda will begin mass production of EVs in 2019. Related Video:

2014 Mazda3 2.0L Hatchback officially rated at 40 mpg highway

The Environmental Protection Agency has spoken, and these are the miles per gallon numbers it has officially bestowed on the 2014 five-door Mazda3 hatchback with the SkyActiv-G 2.0-liter engine: 29 city, 40 highway, 33 combined when fitted with the six-speed manual; 30 city, 40 highway and 33 combined when equipped with the six-speed automatic.
Those numbers exactly match the fuel economy targets that Mazda had set for the car when optioned with the 2.0-liter Skyactiv-G with 155 horsepower and 150 pound-feet of torque. For comparison to other cars in the segment, the EPA numbers for the 2013 Honda Civic sedan are 28 city, 39 highway, 32 combined when its 140-hp, 1.8-liter four-cylinder is paired with the five-speed automatic. The Hyundai Elantra GT gets 27 city, 37 highway and 30 combined according to the EPA when its 148-hp, 1.8-liter four-cylinder is paired with either a six-speed manual or six-speed automatic transmission. The numbers for the 2014 Ford Focus aren't out yet.

Mazda hard at work on Skyactiv 2 engine technology

As Mazda continues the current rollout of its still-new Skyactiv technology, the automaker is already looking at improving its family of engines for even better fuel economy and emissions reductions. Automotive News reports that with stricter fuel economy and emissions regulations planned for 2020 and 2025 in Europe, Mazda will likely release engines with next-generation Skyactiv 2 technology by the end of this decade, and Skyactiv 3 units just five years later.
The latter is expected to focus on improved engine cooling and lessening energy losses, but the big news in AN's report is that the next-gen Skyactiv 2 engines will use Homogeneous Charge Compression Ignition, or HCCI. This type of ignition is very similar to how a diesel engine operates (with high compression and using the compression stroke for fuel combustion rather than spark plugs), a method said to provide a cleaner and more efficient fuel burn - to the tune of a 30-percent improvement in fuel economy compared to current Skyactiv engines. Other automakers, including Hyundai, have already announced they are developing HCCI powerplants with similar technology and characteristics, so Mazda likely won't be a lone wolf here.
Equipped with HCCI technology, Mazda figures to be able to compete with larger automakers in terms of fuel economy and emissions without resorting to hybrid powertrains, continuously variable transmissions or automatics relying on more forward gears (eight or more) for optimal efficiency. Some of the challenges of HCCI, according to AN, include the need for better engine cooling, risk of misfire at high and low rpm and uneven engine performance based on fuel properties.