Definition from Wiktionary, the free dictionary
tractive (not comparable)
- Pertaining to traction.
- This locomotive develops 130,000 pounds of tractive effort.
- 1912, Flight 
- The outer third of the wing of a vulture consists of the wing tips. The inner two-thirds of the wing are cambered (when the wing is extended), and are concerned with lifting effort in unsoarable air and with lifting and tractive effort in soarable air.