Japan’s Mazda has only a tenth of Toyota ‘s research and development budget, but is betting it can make the century-old internal combustion engine as fuel-efficient as hybrids like its rival’s pioneering Prius.
While others move increasingly towards electric cars the gamble on developing new gasoline engines could also show whether a small automaker can survive independently in a high-stakes market for mass-produced passenger cars dominated by the likes of Toyota, GM and Volkswagen.
“People used to say there’s no way a small carmaker could survive unless they find a partner because it wouldn’t be possible to independently pursue costly technologies like fuel cells, electric vehicles and hybrids,” said Mitsuo Hitomi, Mazda’s top powertrain engineer. “But these may not become mainstream.”
Mazda, valued at $13.5 billion and with its roots as a 1920’s machinery toolmaker, has chosen to focus on reducing the energy loss in combustion engines, with technology that is a side-show for bigger companies focused on headline-grabbing electric and hybrid vehicles. The move has already helped achieve big fuel-efficiency gains in Mazda vehicles.
Gasoline engines now utilize at most around 35 percent of the fuel’s energy, with the rest lost mainly to heat and friction. Engines also typically operate well below the peak, at around 20 % efficiency. Mazda wants to improve that to 50 % at peak efficiency and maintain operation closer to peak levels. A first step would be with a breakthrough technology called HCCI, or homogenous charge compression ignition, Hitomi said.
In an HCCI engine, as in fuel-efficient diesel engines, the mix of air and fuel ignites without a spark plug, but carmakers have struggled to achieve ignition at low and high engine speeds. Mazda has solved that with a higher compression ratio, squeezing the air and fuel mixture further and boosting temperatures in the combustion chamber, Hitomi said.
Hitomi said a car with an HCCI engine could have a fuel economy similar to gas-electric hybrids. That could mean that a Mazda3 kitted out with an HCCI engine could run at about 30 km per liter (71 miles per gallon / 3.31 L/100 km) under Japanese standards, about a 50 % increase from its current gasoline engine, and roughly on par with a Toyota Prius.