What record $6.53 diesel actually means for a trucker, a landscaper and a farm at harvest

The national average price of diesel reached $6.5276 a gallon on Tuesday, according to AAA, a new record for the motor club and up from $5.5947 a month ago and $3.6880 a year ago. The government's weekly survey agrees: the Energy Information Administration put on-highway diesel at $6.529 for the week of September 21, up 24 cents in a week and $2.78 from a year earlier.

That is happening while oil falls. Crude dropped about 3% on Tuesday morning after reports, cited by CNBC and OilPrice.com, that Iran could reopen the Strait of Hormuz within seven days if the U.S. eases military pressure. CNBC noted it could not verify those reports and that another Iranian official denied them. Brent traded near $97.73 and West Texas Intermediate near $92.40 in CNBC's snapshot.

So the headline for a business that runs on diesel is not "oil is falling." It is "your fuel bill has not caught up with that yet, and may not for weeks." Here is what the current price does to three very different operations. The gallons below are examples, so swap in your own.

A one-truck carrier: about $4,277 more a month than last year

Take an owner-operator running 10,000 miles a month at 6.5 miles per gallon. That truck burns about 1,538 gallons a month.

• At EIA's $6.529, fuel costs about $1.00 a mile. A year ago, at $3.749, it was about 58 cents.
• That is roughly 43 cents a mile more, or about $4,277 a month (1,538 gallons x $2.78).
• Against a month ago, using AAA's figures, the increase is 93 cents a gallon, or about $1,435 a month.
• In California, where EIA has diesel at $8.246, the same truck spends about $1.27 a mile on fuel.

The carriers that hurt most are the ones hauling at rates set before the run-up without a fuel surcharge, and the ones paid on 30 to 45 day terms while they buy fuel every day. The CheckThisBiz directory lists 24,679 independent trucking and freight firms, the largest counts in Texas (2,868) and California (2,828). For a one- or two-truck operation, a $1,400 monthly swing can decide whether a lane is worth running.

A landscaping crew: about $1,112 a month, with the season ending

Suppose a crew with three diesel pickups plus mowers and a skid steer burns 400 gallons a month. At $2.78 more a gallon than last year, that is about $1,112 a month; against a month ago it is about $373.

The trap here is pricing. Fall cleanups, snow contracts and next year's maintenance agreements are being quoted now. A quote written in late August assumed diesel near $5.59. A snow contract priced for the whole winter locks in whatever fuel assumption you made today. There are 44,163 independent landscaping and lawn care businesses on CheckThisBiz.

A grain farm at harvest: about $8,847 more than last fall

Harvest is the worst possible week for this. The Midwest had the sharpest jump in EIA's survey: $6.680 a gallon, up 43 cents in one week and $2.95 from a year ago. A farm that burns 3,000 gallons running combines and grain trucks through harvest pays about $8,847 more than last fall at that change, and about $1,290 more than it would have a week ago. Off-road farm diesel carries less tax than the pump price EIA tracks, so the dollar level is lower, but the increase moves with the market.

Why the pump has not followed oil down

Retail diesel trails the wholesale market. The NYMEX heating oil contract, the benchmark for wholesale diesel, was near $4.82 a gallon on the OilPrice.com board Tuesday morning, down about 1.4% on the day. If crude's slide holds, retail prices usually ease with a delay. If the Hormuz reports fall apart, as one Iranian official's denial suggests they might, that relief does not come. Nobody knows which, which is the point.

What to actually do this week

1. Read your surcharge clauses. If a contract carries a fuel surcharge tied to the EIA weekly price, check that it is being applied at this week's $6.529, not an old table. If you have no surcharge, add one to every new quote.
2. Put an expiry on quotes. Seven to fourteen days, with fuel named as the reason. A 60-day quote is a bet on diesel.
3. Do not lock a long fixed fuel price at a record high just because you are scared. The crude market is moving the other way this morning. If you want certainty, lock part of your volume, not all of it.
4. Plan the cash gap. A carrier spending $1,400 more a month but paid in 45 days has to fund six weeks of higher fuel before the revenue lands. If that is your situation, our trucking funding page explains the options, including factoring invoices.

Related: our report on oil's fifth day lower and diesel's record, and the crude oil chart.

Sources: AAA; EIA Gasoline and Diesel Fuel Update; CNBC; OilPrice.com; business counts from CheckThisBiz. Gallon figures are illustrative examples. This is general information, not financial advice.