Partners that impose high fuel charges include British Airways and Iberia Airlines. (upgradedpoints.com)
To avoid high fuel charges, try booking with partner airlines: United for flights within the U.S., Taca, Avianca and LATAM for flights to Latin America, and LOT for flights to Europe (rewardexpert.com)
My only question is, doesn't Singapore Airline have much higher fuel charges and booking fees on phone reservations? (richmondsavers.com)