Ethanol injection for knock control

[theholycow]

http://www.newscientist.com/article/...efriendly.html

[...]So says the Ford Motor Company, which on 19 May revealed test results on a novel ethanol-assisted engine. Called a direct-injection ethanol engine, the unit runs primarily on petrol. When it needs to deliver maximum power - to climb a hill or overtake, for example - the engine management computer adds a little ethanol to the fuel injected into the combustion chambers.

This arrangement allows the engine to operate at a much higher compression ratio - a measure of the amount by which the fuel-air mixture is compressed before being ignited - than normal. As a result, an average car engine can be "downsized" to one that should have around 23 per cent better fuel efficiency, Ford says.[...]

Nothing particularly new to us here, but a different combination of things we often talk about.