When market diesel jumps rapidly (for instance from the $3.68 baseline reported a year ago to $6.47 AAA national average), carrier operating margins face immediate compression unless structured Fuel Surcharges (FSC) are enforced.

• DOE/EIA Cents-Per-Mile Peg: The most common North American contract standard assigns a benchmark peg (typically $1.20 to $3.68/gal depending on the contract era) and adds 1¢ per mile for every 5¢ increase in the weekly EIA diesel index.
• The Deadhead Vulnerability: Shippers only pay fuel surcharges on billed loaded miles. When a carrier runs 10%–20% empty deadhead miles to reposition equipment, the additional $2.79/gal inflation on those miles is 100% absorbed by the trucking company.
• Reefer & Auxiliary Units: Temperature-controlled trailers consume 0.4 to 0.9 gallons of diesel per hour regardless of road speed, creating an additional unbilled fuel liability if not itemized.