I was in the shop yesterday going through my spiel with a visitor and the efficiency question popped up as it always does. "Is this one efficient?". This question gets asked almost every time and I listened to myself answering this very important question.
My answer goes something like this: "Are we talking about efficiency, or performance? People think efficiency means its going to give a lot of heat. Well it doesn't. It actually means whether it will require a lot of energy to reach a temperature, blah blah blah....."
I thought to myself, shut up. People ask if a radiator is efficient meaning does it give a lot of heat, irrespective of what the actual dictionary definition means. Remember literally? The dictionary definition actually says it also means figuratively. The reason being, its now used that way.
So, I need to reformulate how I answer this question, but in order to do so, I'll explain how this all works.
Efficiency literally means efficient. Something is efficient when it takes little energy to operate. A low powered car, say 1 litre is going to work using less fuel, but it isn't going to have huge horsepower.
Then we have the comparison of performance. A high performance car is going to have high horsepower, torque, top speed, etc. At the expense of all this power, its going to require more fuel.