ODA's Motor Fuel Quality Program has 3 primary responsibilities:
- Ensuring that motor fuels sold in Oregon meet nationally accepted standards of quality.
- This is achieved through inspections, field screenings, complaint investigations, document review, and lab tests.
- Enforcing Oregon’s Renewable Fuel Standards which require 10% ethanol in most gasoline and 5% renewable content in most diesel fuels (renewable content can be biodiesel or renewable diesel).
- Investigating complaints regarding motor fuel quality.
ODA field inspectors routinely perform basic inspections of all motor fuels offered for sale.
Water is the most common consumer complaint received regarding motor fuel. A small amount of water in your fuel is normal, however if there is significant undissolved water in the gasoline that you purchase then your vehicle may start running rough, lose power, or even stall within a few short miles of the gas station. Sometimes fresh fuel is sufficient to fix a water contamination issue, other times servicing is required to purge the vehicle's fuel system and repair any damaged components.
Motor fuels offered for sale at refueling stations are checked for evidence of water contamination at key points including:
- Storage tank fill pipes are checked for proper seals.
- The storage tank is checked for water.
- Fuel dispensed through the nozzle is inspected to ensure it is clear and bright and free of undissolved water and sediment.
Anti-Knock Index, or octane, is used to market and price gasoline in the US market. ODA checks all grades of gasoline offered for sale at each gas station to make certain that the posted octane rating correctly represents the gasoline sold.
You pay a premium for "premium" gasoline which should inlude both higher octane ratings and a better fuel additive package. It can, however, be hard for you to know that you are getting the fuel you are paying for in a modern car since the engine management systems in these vehicles will automatically adjust to control engine knock. Tell tale signs of of engine knock due to low octane fuel will be more prominate older vehicles or high performance engines operated under a heavy load such as climbing a steep hill in high gear.
Three basic checks are routinely performed at the gas station:
- Product certification documents are inspected (fuel dealers are required to certify the octane rating of each load of gasoline delivered on the delivery documents)
- Dispenser blending ratios are verified (modern fuel dispensers blend regular and premium gasoline to produce a mid-grade blend)
- Gasoline is tested using portable octane analyzers (field octane analyzers can detect a discrepancy between the posted octane and the actual octane of the fuel dispensed)
ODA places a high priority on fuel quality complaints because it is difficult to substantiate a complaint after one or more fresh fuel deliveries have been made at a gas station.