According to Hank and Buck Strickland, Thatherton Fuels has been placed on probation and censured by the Texas State Propane Association on multiple occasions. Compared to Strickland Propane and the other propane suppliers of Heimlich County, Thatherton Fuels is generally seen as second-rate.
In the Season 4 episode "Rodeo Days," it is revealed by a rodeo announcer that one of Thatherton Fuels' slogans is "Selling the heat with warmth." Upon hearing this, Hank Hill displeasingly remarks that the slogan is a lie. In the Season 6 episode "Joust Like a Woman", Thatherton Fuels attempted to beat Strickland Propane to win an expensive propane deal by using the always-risky tactic of underbidding the low bid.
The tag line used in other parts of the series, and appearing on Adult Swim show promo spots is "Thatherton Fuels - When you want propane done right."
The store is known to steal Strickland customers (Pat Rich), by learning their interests and then acting like friends online at Myspace.