I was looking at two cars that friends have, and I was comparing the specs, and don't understand what is going on.
One is a 2017 7 seater Citroën C4, which has a 1.2L 3-cylinder petrol engine, producing 131hp (97kW). The car weighs 1372kg with a claimed top speed of 125mph
Another is a 2022 Yaris Hybrid, which has a 1.5L 4-cylinder petrol engine + electric, but only produces 100hp (74kW). The car is lighter at 1160kg, with a claimed top speed of 100mph.
What gives with the power? How can a 5 year newer engine that is 300cc bigger and has an extra cylinder produce LESS power than the older engine? Given high school/degree level combustion engine physics it should just get more powerful the bigger you make the engine? If the age was the other way around I'd just put it down to quality/design, but this feels like there is a missing variable here, but what is it? Is it something to do with fuel efficiency trade off?
If the idea is that we increase efficiency but reduce power, why does this result in a bigger engine. My understanding was that to maximise efficiency we want to compress the air-fuel mix as much as possible, so that it does maximum work when it expands? Or looking at the Carnot diagram, so that we get the biggest area we can - so does this mean the idea is to burn the same amount of fuel in a bigger cylinder will make a more efficient engine? Or is the idea to simply run an engine at lower revs, getting more power from each cycle?
Is there some significance in 3-cylinder vs 4-cylinder? Again, I would have assumed more means more power.