I Published a Carrier Fuel Comparison in June. It Reversed on August 10.

In June I published a comparison of the two carriers’ Ground fuel surcharges. On July 3 I updated it: FedEx had restructured, raising the floor while diesel fell, and the change would cost shippers nothing until fuel came down.

I closed with a specific call:

Once diesel slips below roughly $4.50, FedEx Ground becomes the more expensive carrier, running about 50 basis points above UPS at every lower price point.

That was correct when I wrote it. On August 10 it inverted.

If you ran a carrier comparison on the strength of that piece, the conclusion you are carrying is now backwards, and I would rather you hear it from me.

What changed

UPS published a new Ground fuel surcharge structure on August 10, moving its diesel pivot from $4.45 to $4.99 and the surcharge at that pivot from 24.50 percent to 26.00 percent. It did the same thing to Domestic Air the same day.

The Ground pivot now matches FedEx’s exactly, and so do the step sizes. What differs is the surcharge at the pivot: UPS 26.00 percent against FedEx 25.50.

The crossover is gone

This is the part worth sitting with.

Under the old UPS structure the two carriers traded places depending on where diesel sat. Above roughly $4.83 UPS printed higher. Below it FedEx did, by the 50 basis points I described in July. There was a crossover, and which carrier was cheaper on Ground genuinely depended on the fuel market.

There is no crossover anymore. I modeled both structures at every cent from zero to nine dollars a gallon, and UPS returns exactly 50 basis points above FedEx at every single price. Not on average. At every price.

At $4.00 diesel, FedEx was 50 basis points more expensive in July. Today UPS is 50 basis points more expensive. The relative position did not shift. It flipped, and it flipped everywhere at once.

How it was done, which is the more useful finding

The construction is worth understanding because it will be used again.

UPS moved the Ground pivot up 54 cents. The table steps up in 9 cent increments worth a quarter point each, so 54 cents is exactly six steps, or 1.50 percentage points. The surcharge at the pivot moved up exactly 1.50 points.

Those two adjustments cancel. Above the new pivot the new table returns the identical percentage as the old one at every diesel price, all the way up. Below it, the new table runs a full point richer across most of the range, and the structural floor moved from 20.25 percent to 21.25.

Domestic Air is the same construction. Pivot up 25 cents against a 5 cent step, which is five steps and 1.25 points, matched by a 1.25 point move at the pivot.

Now run the check on FedEx’s June change, the one I wrote about. Pivot up $1.44 against the same 9 cent step is exactly sixteen steps, or 4.00 points. The surcharge at pivot moved exactly 4.00 points.

Three restructurings, two carriers, three months, one specification: shift the pivot by a whole number of up-steps and raise the surcharge at the pivot by the matching amount. The result is a change that is arithmetically zero above the new pivot and a floor lift below it.

At the time I read that as a notable move by one carrier. It is a method.

The condition inverted too

The July piece described a rising floor in a falling diesel market, which is what made it striking at the time.

Diesel is not falling now. On-highway diesel went from $4.578 on July 6 to $5.257 on August 10, and sat near $3.71 a year ago. Gulf Coast jet went from $2.816 to $3.736 across four weeks.

So the August changes landed with fuel well above every one of the new pivots, which is the range where they are worth precisely nothing. Whatever the intent behind the timing, the effect is that neither August change moved anybody’s invoice on the day it took effect.

What to actually do with this

Re-run any Ground carrier comparison you built before August 10. If it used fuel as a differentiator, it is stale. The crossover logic that made the answer depend on diesel no longer applies to these two structures.

Stop treating the fuel table as a tiebreaker. A flat 50 basis point spread across the entire price range is a simpler input than a crossover, and it means fuel structure no longer flips the comparison at any plausible price. It shifts it by a constant.

Check what your own agreement references. If it points at the carrier’s published index with no cap and no lock, you have agreed in advance to every table that carrier publishes for the life of the agreement, including three published in the last three months.

Model at lower fuel, not current fuel. I said this in July and it is more true now, because there are two more restructurings sitting in the range below today’s prices waiting to be discovered.

The bottom line

The specific conclusion I published lasted about six weeks. That is worth saying plainly, because the useful lesson is not that a carrier comparison changed. It is that a carrier comparison built on fuel structure has a shelf life measured in weeks now, and almost nobody re-runs one that often.

Three structural changes in three months, none of which required a shipper signature, an amendment, or a rate announcement, and all three of which produced a zero on the invoice the day they landed.

Takeaway: If the last time you compared carriers on fuel was more than a quarter ago, you are working from a conclusion the tables have already overtaken.

When did you last re-run a carrier fuel comparison, and would you have noticed if the answer had changed?