By Jeffery Fogg | This Is Topeka
September 17, 2026
TOPEKA, Kan. — If you pulled into a Topeka gas station Wednesday night and did a double take at the pump, you probably weren’t alone.
A photo taken Wednesday evening shows diesel selling for an eye-popping $6.299 per gallon, while regular unleaded containing ethanol was $4.199. Ethanol-free gasoline was even higher: $4.749 for 87 octane, $4.899 for midgrade and $5.199 for premium.
And unfortunately for drivers, those prices aren’t an isolated fluke.
AAA reported Thursday morning that the average price of diesel in Topeka has reached $6.0587 per gallon — the highest average diesel price AAA has recorded for the city. Just one year ago, Topeka diesel averaged $3.3937.
That means diesel is now roughly 79% more expensive than it was a year ago.
Regular gasoline has climbed sharply as well. AAA lists Thursday’s Topeka average at $4.0007 per gallon, compared with $3.8925 Wednesday, $3.8614 a week ago and just $2.9369 one year ago.
For someone filling a 25-gallon diesel pickup at the $6.299 price photographed Wednesday night, a full tank would cost about $157.48.
For businesses operating several diesel trucks, construction equipment, delivery vehicles or agricultural machinery, the numbers add up considerably faster.
Why is diesel so expensive?
The problem extends well beyond Topeka.
AAA’s national diesel average reached $6.3956 Thursday, another record in its data, while regular gasoline averaged $4.4386 nationally.
Reuters reported last week that the U.S. diesel average had crossed $6 for the first time amid disruptions to global fuel supplies, including conflict affecting Middle Eastern supplies, attacks on Russian refineries and export restrictions. U.S. diesel inventories have also remained unusually tight.
The Midwest has another immediate concern. ExxonMobil’s 264,000-barrel-per-day Joliet, Illinois refinery temporarily shut down Sunday following a power outage. Reuters reported that the refinery is an important supplier of gasoline and diesel to the Midwest and can produce roughly 11 million gallons of fuel per day.
Oil itself remains expensive, although crude prices have eased somewhat this week. On Wednesday, West Texas Intermediate crude settled at $102.43 per barrel and Brent at $105.83 as additional Saudi crude shipments helped ease some supply fears.
Kansas drivers are feeling it
Kansas remains somewhat cheaper than the country as a whole for regular gasoline, but the difference doesn’t make $4 gasoline feel inexpensive.
AAA’s statewide average Thursday is $4.0644 for regular and $6.0918 for diesel. Kansas diesel averaged $5.5818 only a week ago and $5.0633 one month ago. A year ago, it averaged $3.4328.
The consequences also won’t necessarily stop at the gas pump. Diesel powers much of the equipment that moves goods, builds homes, farms crops and delivers products. When fuel costs increase dramatically, businesses can face pressure to absorb those expenses or pass some of them along through higher prices.
For now, the numbers displayed Wednesday night tell the story pretty clearly:
$4.199 for regular. $5.199 for premium. And $6.299 for diesel.
For Topeka motorists accustomed to Kansas being one of the less expensive places in the country to fill a tank, $6 diesel has arrived.
Photo: Fuel prices photographed at a Topeka-area gas pump Wednesday night, Sept. 16, 2026. Photo provided to This Is Topeka.
