The Pump Went Up 71 Cents in Four Weeks

The national average hit $5.967 a gallon on September 7. That is 36.8 cents in one week and 71 in four.

If the last few fill-ups felt worse than usual, they were. The number backs it up.

The EIA's weekly retail on-highway diesel survey for the period ending September 7 put the national average at $5.967 a gallon.

The move, not the number

A single price is easy to argue about. The direction is not:

One week: $5.599 to $5.967. Up 36.8 cents, or 6.57%.

Four weeks: $5.257 to $5.967. Up 71 cents, or 13.51%.

Seventy-one cents in a month is the part that matters. On a truck getting 6 miles per gallon, that is roughly twelve cents more per mile than four weeks ago, before anything else about your operation changed.

Why the four-week number is the one to quote

A single week can be noise. Refineries go down for maintenance, a storm closes a channel, a cargo arrives late. Any of those moves a weekly average and then gives it back.

Four weeks is long enough that the noise cancels and short enough that it is still about now. When you are explaining to a broker why a rate that worked last month does not work this month, the four-week figure is the one that survives the conversation.

It is also the number to use on your own side. If you set a fuel budget four weeks ago, it is 13% short today, and nothing about your driving caused that.

Read the survey for what it is

One caution that saves arguments at the fuel desk: this is a weekly survey, not a daily quote.

A daily average from another source can print a different number the same week without either being wrong. They are not measuring the same thing. When you compare a rate, a surcharge or a bid against a fuel price, check which series the other side is using before you decide somebody made an error.

Worth knowing too: this dataset does not publish all fifty states. Regional PADD figures are not state figures, and treating one as the other is how a lane gets priced off a number that never applied to it.

What actually moves at your end

You do not control the price. You control how many gallons the truck burns to do the same work, and that list is shorter than it looks:

Tire pressure. The cheapest fuel saving there is, and the one that quietly disappears every time a truck sits a week. Under-inflated tires cost fuel on every mile and take tread with them.

Alignment. A truck that is not tracking straight is being pushed sideways all day. You pay for that twice: in fuel and in rubber.

Dragging brakes. A brake that never fully releases turns diesel into heat. It shows up as a hot wheel end long before it shows up as a complaint.

Overnight idling. At six dollars a gallon, every hour parked with the engine running to keep a cab comfortable is a purchase. It is the one line item where a decision made once keeps paying every night.

The math changes when the price changes

Here is the part that gets missed when fuel spikes: equipment that was not worth it at four dollars can be worth it at six, and the reverse is also true.

An investment that pays back in saved fuel gets faster as the price rises, because the payback is measured in gallons and the gallons cost more. That is not a reason to buy anything today. It is a reason to redo the arithmetic with today's number instead of the one you used the last time you ran it.

The same applies to a rate you accepted, a surcharge you agreed to and a lane you kept out of habit. Every one of them was priced against a diesel number, and that number moved 13% in four weeks.

What to do this week

Check every tire on the truck and the trailer with a gauge, not a boot. Write down your current cost per mile with the new fuel number. And if the truck has been wandering, shuddering or eating tires on one edge, get it looked at now rather than after the next month of fuel.

We do alignment, suspension and tire work in Houston, Dallas and Monterrey: thetrucksavers.com.

Source: U.S. Energy Information Administration, Weekly Retail On-Highway Diesel Prices