Diesel, the fuel surcharge worked out per mile, and the fuel tax rate in every state a Texas carrier runs.
A Texas surcharge is benchmarked against Gulf Coast PADD 3, because that is the smallest region the Energy Information Administration publishes weekly. Put your own mileage and base into the calculator below and check the number in your rate confirmation.
Where diesel stood in the week ending 24 August 2026.
The last six weeks, U.S. average
Bars are scaled to the highest value shown, not to zero, so the shape reads as movement rather than magnitude. All six weeks from the EIA weekly U.S. on highway diesel series.
Why there is no Texas number
EIA publishes weekly diesel for the United States, the five PADD regions, selected sub regions, and California. The Texas page carries gasoline only. A carrier benchmarking a surcharge to a Texas diesel series is benchmarking to something the agency does not publish weekly.
Arizona sits in PADD 5, the West Coast region, which is not shown above because we did not retrieve that series in this pass. We would rather say that than print a number we did not read.
Coverage described at the EIA gasoline and diesel fuel update. Region composition in the EIA PADD map. Texas page: EIA Texas weekly retail.
Work the surcharge on your own mileage, not on a table somebody handed you.
The standard formula is the published diesel price minus your base fuel price, divided by your miles per gallon. The base is the diesel price already assumed inside the linehaul rate, so the surcharge only recovers the part above it. Change the two inputs and the arithmetic follows.
Diesel price from the EIA Gulf Coast weekly diesel series, week ending 17 August 2026, retrieved 25 August 2026. Brokers use different bases, different reference series, and different update days. Confirm which one is written into the rate confirmation before you sign it.
The diesel tax rate in every state a Texas carrier is likely to touch.
Rates apply to travel from 1 July through 30 September 2026. The IFTA matrix carries a notice that the quarter is not final until 4 September 2026, so treat these as published rather than settled.
| State | Special diesel, per gallon | Gasoline, per gallon | Change from second quarter | Source |
|---|---|---|---|---|
| Texas | $0.2000 | $0.2000 | No change | IFTA 3Q2026 |
| Oklahoma | $0.1900 | $0.1900 | No change, lowest in the group | IFTA 3Q2026 |
| Louisiana | $0.2000 | $0.2000 | No change | IFTA 3Q2026 |
| New Mexico | $0.2100 | $0.1200 | No change | IFTA 3Q2026 |
| Mississippi | $0.2400 | $0.2400 | Up 3.00 cents from $0.2100 | IFTA 3Q2026 |
| Arizona | $0.2600 | $0.1800 | No change | IFTA 3Q2026 |
| Kansas | $0.2600 | $0.2400 | No change | IFTA 3Q2026 |
| Tennessee | $0.2700 | $0.2600 | No change | IFTA 3Q2026 |
| Arkansas | $0.2850 | $0.2470 | No change | IFTA 3Q2026 |
| Missouri | $0.2950 | $0.2950 | No change | IFTA 3Q2026 |
| Colorado | $0.3350 | $0.2800 | Up 1.00 cent from $0.3250, highest in the group | IFTA 3Q2026 |
All rates from the IFTA, Inc. tax rate matrix for third quarter 2026, retrieved 25 August 2026. The spread from Oklahoma to Colorado is 14.50 cents per gallon, which is real money on a lane that crosses both.
Colorado is three charges, not one
Components reconcile exactly to the IFTA rate. From Colorado Department of Revenue fuel tax and fee rates. Colorado's fees step up on a published schedule, so this figure changes again.
Mississippi is on a step schedule
Steps from the Mississippi Department of Revenue petroleum tax rates. Federal rate from the Federation of Tax Administrators state motor fuel tax compilation.
File with the IFTA rate. Not the posted state rate.
Some states publish a posted excise rate that differs from the rate IFTA uses, because IFTA folds surcharges and additional taxes into one number. The rate on your quarterly return is the IFTA rate in the table above, every time. Texas is one of the simple ones: the posted rate and the IFTA rate are both 20 cents per gallon (Texas Comptroller, diesel fuel tax).
The filing that follows. IFTA returns are due 30 April, 31 July, 31 October, and 31 January, moving to the next business day on a weekend or holiday. Texas charges the greater of $50 or 10 percent of the tax liability on a late return, including a return with no travel and no tax due (Texas Comptroller fuels tax FAQ). The full calendar is on the deadline page.
Limits worth stating.
Not a forecast. These are published weekly and quarterly figures for a stated period. Nothing here predicts next week's diesel or next quarter's rates.
Not tax advice. Rate tables are reference material. Your IFTA liability depends on your miles by jurisdiction and your fuel purchases, and it belongs to you and your accountant.