Thread: Efficient motor
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Old 03-19-2019, 03:35 AM   #9 (permalink)
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Originally Posted by Spaghetti Man View Post
I want to isolate what makes the engine efficient.
Efficiency might be achieved through different pathways...

A 25cc motor will be super efficient compared to a 250cc motor however the 25cc motor cannot travel at 110km per hour.
You might be looking at efficiency from a perspective of fuel consumption per a given amount of time, while considering the specific fuel consumption for power provided is more relevant (often mentioned as BSFC - brake-specific fuel consumption).

Even engine capacity is not a definitive indicator as an engine may be poorly designed or not designed for efficiency.
That's one of the reasons I'm unfavorable to the "people's car" policy in my country considering simply the displacement up to 1.0L in order to grant lower taxation. Similar models available in neighboring countries with slightly larger displacement such as 1.2L or 1.4L achieve better fuel-efficiency due to the higher torque at lower RPM bands and higher gearing.
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