Efficiency of Electric Motors
Shaded pole motors are only 30% efficient.
Other brushed ones are 60%.
Electrically commutated motors are 70-83% acc to this article.
- Brushless motors were first made in 1962. 
- Small electric motors are 10-70% efficient. BLDC are Bout 2x as efficient. Good report comparing BLDC to brushed at small scale of few grams -