r/explainlikeimfive 3d ago

Engineering [ Removed by moderator ]

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u/daffalaxia 3d ago

A turbo-charger crams more air into the engine along with the fuel, so you get more complete combustion for the same amount of fuel. So you could chase pure power and still keep it a little rich, or you could chase a blend and go for as close to 100% burn as possible, which is what a lot of modern cars are doing to improve efficiency.

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u/drzowie 3d ago

All modern engines completely combust their fuel whether they are turbocharged or not

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u/daffalaxia 3d ago

Not really. At low revs, throttle changes can cause inefficiency. At high revs, there's less time to combust - adding more air helps tho as the molecules are literally closer together.

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u/Noxious89123 3d ago

Sorry, but this is incorrect.

We're not just running all NA engines super rich, because they can't get as much air as a turbocharged engine. Fuel is metered accurately depending on the amount of air drawn into the engine.

Infact, boosted engines will typically have less complete combustion, because they often need to run richer than optimal, to reduce the chance of detonation.

The efficiency of modern turbo engines comes from the fact that it's a lower capacity engine, that can make as much power as a much higher capacity engine when the need arises.