Do gas station pumps measure fuel equally?

| 23/08/2018

Every gas station in the US I’ve ever been to has a tamper-proof seal from a regulatory body sealing the measurement mechanism for a fuel pump and noting the date it was last inspected. However, I have never seen an equivalent here in the Cayman Islands. How can customers be certain that the volume of fuel they pay for is what they receive? I would think it would be very tempting for an unscrupulous station owner to put a “thumb on the scale” or at the very least fail to recalibrate pumps which underdeliver fuel. Is there a process in place to protect consumers at the pump?

Advance ChevroletAuntie’s answer: I checked with the fuels inspectorate at the Utilities Regulation and Competition Office (OfReg) and a system is indeed in place to prevent any funny business when it comes to measuring fuel in Cayman.

All gas stations in the Cayman Islands are required to have their pumps calibrated. An OfReg fuels inspector explained that calibrations are conducted at least once a year as required under the Dangerous Substances Regulations, 2017. Before that came into effect, calibrations were still conducted to satisfy the public interest.

In case you were curious about the specifics of calibration, the inspector explained that it is done by a third party, meaning not a representative of the gas brand being checked, and witnessed by OfReg inspectors. Importantly for your concerns, he added, “Once calibration is completed, OfReg inspectors place tamper-proof seals on the inside of the dispensers so that calibration cannot be changed.”

In addition, the margin of error allowed for fuel station dispensing meters is only plus or minus 0.22%, as determined from guidelines provided by the US-based National Institute of Standards and Technology.

After the calibration is completed, a sticker is placed on the outside of the dispenser, stating the date it was done. The stickers are orange, carry the OfReg logo and are placed in the same spot on all pumps. Below is a photo of a sticker in place so you will know where to look.

CNS Local Life

However, if you cannot find a sticker, you can contact OfReg by emailing the fuels inspectorate at But the OfReg official also pointed out that the lack of a sticker does not mean the meter was not calibrated. “If the sticker is not in place, it will require some probing by OfReg as these are designed to remain in place once affixed. Regardless, the tamper-proof seal on the inside of the dispenser is the important component.”

Tags: , ,

Category: Ask Auntie, Misc Questions

Comments (5)

Trackback URL | Comments RSS Feed

  1. Anonymous says:

    The answer is yes, they all equally measure inaccurately.

  2. Anonymous says:

    There used to be a container to measure an Imperial gallon, which they use to calibrate to pumps. Haven’t seen one being used for years.

  3. Anonymous says:

    Note the quality is highly variable. You may get your fair 20 imperial gals of something, but it’s not always what you want to be putting in your vehicle or boat. Additives, rust particles, and even salt and fresh water are present in many old retail stations and are pumped into your tank (along with fuel), at your expense. The Fuel Inspectorate published a report a few years ago, with sample results and photos, but then redacted the station names/locations of the worst tested so the public wouldn’t know who they were. Station owners (at the time, and maybe still) were also allowed to import their own fuel from wherever they liked, not necessarily from the USA depots or main fuel terminal. The photos of the diesel samples were a rainbow of colours from samples taken around the island. Quality is what folks should be concerned about, esp if you are heading-out fishing to the banks, or refueling a $50k+ automobile.

  4. Anonymous says:

    Does anyone check the scales at the grocery stores? Asked XXXXX to double check grapes after my cashier weighed them in over a pound (I only had a small bunch removed from a large bag) and very different results at customer service area

    • Anonymous says:

      Same here, and there’s a woman at the market at Cricket field, whose weighing scale is off, in her favour, by about half a pound!
      Upon my pointing that out and refusing to pay for half a pound extra, she pretended to adjust it and knocked off half a dollar .. meanwhile her empty scales were still showing half a pound.