It's Not the Base Rate That Moves — It's the Surcharge
When diesel prices rise or fall, it's rarely the negotiated linehaul rate that changes — it's the fuel surcharge (FSC), a separate line item calculated specifically to track fuel cost changes without renegotiating the entire rate every time diesel moves.
How the Surcharge Is Actually Calculated
Most fuel surcharges are tied to the U.S. Department of Energy's weekly national average diesel price, using a published scale that increases the surcharge in set increments as diesel crosses certain price thresholds. This means it's a formula, not a broker or carrier's discretion.
Why This Actually Protects Shippers
Tying fuel costs to a transparent, published index protects shippers from arbitrary rate increases when fuel spikes, while also protecting carriers from being locked into an unprofitable rate if diesel rises sharply after a contract is signed. Both sides have certainty.
What Shippers Should Actually Watch
Ask how the FSC is calculated and how often it updates — weekly is standard and fairest for both parties. Confirm whether it's based on national average diesel price or a regional index, since regional pricing can differ meaningfully from the national number, especially on the coasts.
IZY Logistics is a licensed freight broker (MC #1615290) serving shippers across the United States. Get a competitive quote in under 30 seconds.
Get a Free Quote →Frequently Asked Questions
How do diesel prices affect my freight rate?
Diesel price changes typically flow through a separate fuel surcharge line item, not the base linehaul rate, which stays negotiated separately.
How is a fuel surcharge calculated?
Most fuel surcharges are tied to the U.S. Department of Energy's published weekly national average diesel price, using a set formula rather than discretionary adjustment.
How often does a fuel surcharge update?
Weekly updates are standard industry practice and considered fairest for both shippers and carriers.
Is fuel surcharge based on national or regional diesel prices?
It depends on the agreement — most commonly it's the national average, though regional indexes exist and can differ meaningfully, particularly on the West Coast.
Does IZY Logistics use a transparent fuel surcharge formula?
Yes. Our fuel surcharge is tied to published DOE diesel pricing data, not set at our discretion, so it's verifiable by the shipper.
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