Thread: Mazda design petrol engines without spark plugs which increase fuel efficiency by 30%

Mazda claims to have designed a vehicle that will largely eliminate the need for spark plugs in petrol engines, increasing fuel efficiency by as much as 30%. The development also increases the existential threat facing diesel engines because its fuel economy could match diesel’s performance without high emissions of nitrogen oxides or sooty particulates

Mazda said it would sell cars from 2019 with a newly developed petrol compression ignition engine, a technology that automotive manufacturers, including deep-pocketed rivals such as Daimler AG and General Motors, have been chasing for decades. The engine ignites petrol through compression, removing the need for spark plugs and increasing fuel efficiency.

But Mazda said its Skyactiv-X engine would have spark plugs that would be used in certain situations such as at low temperatures.

Mazda boosts petrol engine efficiency in fresh blow to diesel | Business | The Guardian

Originally Posted by PAT303

Mazda simply held the inlet valves open passed bottom dead center to reduce pumping losses,that does not make it an Atkinson cycle engine.Rotaries are a design dead end,the reason no other manufacture bothered with them. Pat

yes which is creating an Atkinson type cycle on an otto cycle engine that yes does reduce pumping losses which improves engine efficiency and if you want a fuel miser na engine that's what you do, just ask Toyota with their 1.5L Prius engine, if you do it with boost it then becomes a miller cycle on an otto cycle engine

the nsu was flawed and rushed out to beat Mazda to the market with the engine essentially still in prototype stage while Mazda's 10a was more production ready but until the masses got hold of them that was when more flaws became know and then due to only mazda continuing to go with the rotary took until the 13b to get enough mechanics to know how to work on them (no google back then)

Atkinson cycle is similar to miller cycle but with out boost

as for design dead end most major car manufactures had production ready engine's ready to go and then the 73 oil crisis hit and due to their fuel usage they all pulled the pin apart from Mazda, so to achieve what they have with it for only one company doing all the r&d on it they have done remarkable well, it also gave Mazda something to set it apart from all other Japanese manufacture's.

with direct fuel injection Mazda should have an engine that is now more economical and able to meet new emission laws as well it should also mean they can run much higher compression ratio's for greater performance.
will it ever make low down torque like a big piston engine maybe if you made it have a larger elliptical crank (btw this is what Mercedes and gm had done) to allow more torgue or you build it as a very efficient high rpm air pump which is what they have been doing so far with their halo cars in the rx7 and rx8

as for whats special about it its the first time something as volatile as petrol has been able to controllable combusted with compression ignition