I asked the internet, as you do, for its opinions on the relative efficiency of the two stroke engine as compared to the four stroke variety and received answers, some of them true.
Here are a few answers, some or all of which are complete male cow droppings. Can you identify which, if any, are true?
1. Two strokes are less fuel efficient because they use fuel each time the piston goes down rather than every second time.
2. Two strokes have poorer durability because they need to run at much higher rpm
3. Two strokes are always less fuel efficient
4. Two strokes produce twice the power of a four stroke
Answers after the smokiness.
1 is rubbish
2 is more rubbish (they usually are less durable but that’s not why)
3 is sometimes wrong. Small two strokes like you have in a chainsaw or an old bike are inefficient but the huge diesel ones you find in large ships are the most fuel efficient engines available
4 is exaggerated. Two strokes produce more power than a normally aspirated four stroke but not twice as much