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Monday, May 29, 2017
Southwest Louisiana ,


Informer: State checks octane levels of retail gasoline

Last Modified: Wednesday, August 28, 2013 11:00 AM

By Andrew Perzo / American Press

What assurances are there that guarantee we’re getting the grade of gasoline, at the pump, that we are paying for?

According to the state Agriculture Department’s website, inspectors visit filling stations at least once a year to verify pricing methods, gauge pump accuracy and sample fuel for analysis.

“Samples are sent to the motor fuels testing lab in Baton Rouge and analyzed to ensure that these fuels meet certain American Society for Testing and Materials standards,” Veronica Mosgrove, a department spokeswoman, wrote in an email.

“One of these tests involves obtaining an octane rating to verify that the posted octane sign is in fact what is being sold to the consumer.”

Stations whose gasoline fails to meet the standards must stop selling the fuel and correct the problem, she said.

State regulations say that the words “premium,” “super,” “supreme” or “high” can be used to describe gasoline that has an octane rating — also called “antiknock index” — of at least 91.

For “midgrade” or “plus” gasoline, the number must be at least 89. Gas described as “regular” and “unleaded” must have a rating of at least 87.

“The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites,” reads an article at

“When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine.”

The higher the octane rating, the more compression the gasoline can withstand.

The ratings comprise the averages of the results from two different engine test protocols — the research octane method and the motor octane method. Hence, the mathematical formula on pumps’ yellow octane panels: (R+M)/2.


Parish ordinance set weight limit in 1969

How does the Calcasieu Police Jury decide on the weight limits for parish roads?

“In 1969, the Police Jury passed an ordinance that placed a 10-ton weight limit on all hard-surfaced roads in the parish. Any owner carrying heavier loads is to negotiate in advance with the parish regarding use of the road,” Tim Conner, parish engineer, wrote in an email.

“There is an exception that excludes vehicles from the maximum weight limit that are transporting materials or supplies for the construction of residences or other buildings on tracts of property accessible only by roads or streets subject to the weight limit.”


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The Informer answers questions from readers each Sunday, Monday and Wednesday. It is researched and written by Andrew Perzo, an American Press staff writer. To ask a question, call 494-4098, press 5 and leave voice mail, or email

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