Frequently Asked Questions

Q. I filled up at the gas station yesterday and put 15 gallons of gas in my tank. However, when I got to the station, my fuel gauge still was on 1/4 of a tank and my owner's manual says the tank only holds 16 gallons. How can this be? Or, I bought a new gas can the other day at the local hardware store. It's supposed to be a five gallon can but I got 5 ½ gallons in it. I think the pump must be off.

A. This is the complaint we get the most, and the short answer is that all tanks are not created equal. The stated capacity of your gas tank in your owner's manual or what's stamped on your gas can is often more of an approximation than a fact. A major manufacturer may buy fuel tanks from a variety of suppliers, all of which may hold either a little more or a little less than the stated capacity. Also, the volume of fuel contained in the filler tube will vary. In almost every instance when we retest the pump in question, it is found to be within tolerance (+/- 0.025 gal. for every 5 gal. dispensed). Even so, we will investigate all complaints filed with the Bureau.

Q. Why is the regular unleaded gasoline only 85.5 octane here in Montana while in other states the regular unleaded is 87 octane?

A. The antiknock or octane rating of a fuel is a measure of its resistance to knock. The antiknock requirements of an engine depend on numerous factors, including engine design, operation, and atmospheric conditions. Automobiles manufactured prior to 1984 could, due to Montana's altitude, operate on a fuel having a lower octane rating and achieve the same performance that other cars using 87 octane fuel had at sea level. Since the advent of sophisticated engine control technology starting in 1984, however, the effect of altitude upon octane rating has declined to the extent that the newest cars require the listed octane as found in the owner's manual regardless of the altitude.

While the minimum antiknock rating in Montana is 85.5 for regular unleaded fuel that is not necessarily what is found. Due primarily to competition and/or multiple suppliers of refined products, regular unleaded gasoline found in Western and Northeastern Montana usually has an octane rating of around 87.0. Central and Southern Montana's fuel octane rating is generally found to be between 85.5 and 86.0

Q. When I buy products at the deli counter, am I paying for the container? How would I know?

A. Any type of deli item must be sold on a net weight basis. The weight of the container is called "tare" and is not included in the net weight. Almost all scales now in use at deli counters are of the digital computing type and show the weight of the product, the price per pound, and the total selling price on a digital display that faces the customer. Additionally, the customary practice in most stores is to assign a store code to each item. Information included in this code, which is stored in the scale, contains the name of the item, the price per pound, and the correct tare weight for the container which should be used. So when you want to purchase an item, the counter person will enter the store code for your item and the display panel will show the selling price and the weight display should show a negative number which represents the container or tare weight being zeroed off the scale. If you do not see this negative number displayed when the code is entered, you may be paying for the container and should report this to the Bureau.

Q. I'm thinking about going into business for myself and I'm going to be using some scales. Do I need to license them?

A. All devices, whether weighing or measuring, that are used to determine a price for any commodity that will be sold must be licensed. For more information on licensing please contact our office.

Q. Why should I use a registered repair company to install or repair a device?

A. Companies who register with us can install or service a device and when they certify the device as accurate, the device is legal to use, as long as it is also licensed.  Not all devices sold are legal to use in Montana, so a service company can also guide you to a correct purchase, or you can call the office to see whether a particular device is legal in this state.  In addition, the registered service company has forms called "Placed in Service" forms, which they submit to us so that you do not need to contact us about your device being repaired or a new device being installed, and our inspectors will schedule the earliest opportunity to test when we receive that placed in service order.

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