Mandan Fuel Matter Frequently Asked Questions

What exactly happened?

We began to receive reports around Oct. 13 that customers of Tesoro-supplied fuel stations in the Bismarck/Mandan area were experiencing engine trouble. Upon investigating the matter, we concluded that the gasoline supply delivered was off-spec, which can cause engines to run improperly. We do not anticipate any lasting effects from the fuel and we recommend that consumers who think they may have been affected call our toll-free number (877-876-5383) for assistance.

Has all the fuel been replaced?

As of Tuesday evening, Oct. 18, those service stations known to have been affected had been visited by Tesoro personnel, pumped out, and replenished with new fuel supplies. 

As we learn of additional concerns/complaints from those areas that are located at greater distances from wholesale/distribution centers, we are sampling and replacing off-spec gasoline supplies at any affected locations. 

We continue to encourage consumers to contact our call center with additional questions, reports or concerns.

What stations have been affected?

The best and most current source of information regarding whether fuel in your community has been affected continues to be your local retailer.

What does “off spec” mean?

“Off-spec” refers to fuels that are considered “off-specification,” meaning that one or more of the components of the fuel blend falls outside certain standards. While rare, off-spec fuel may cause performance issues in vehicles. 

What will happen to the bad fuel?

Any off-spec fuel that is pumped out of affected locations is being returned to Tesoro to be re-refined so that it meets appropriate fuel specifications.

The fuel removed by automobile dealers and other service providers will be properly disposed of by the service providers or third parties that specialize in appropriate disposal.

How did this happen?

We are conducting an investigation to determine exactly how the off-spec gasoline was created.

How do customers get reimbursed for the service to drain the fuel?

First, the best source for information is our toll-free number, 877-876-5383, which is staffed from 8AM – 5PM Central.

Tesoro has made arrangements with several local area service providers where consumers will not have to pay for the cost of draining. The service providers will be reimbursed by Tesoro. Our call takers at 877-876-5383 have information about specific locations.

Consumers can also go to any other service provider they choose, pay for the service and then Tesoro will provide reimbursement.  Our call takers at 877-876-5383 have the details on that process.