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driving concern

Where do you buy gas? Tell us in the comments section.Juan Guillermo Lobo

Am I losing something by buying from an off-brand or independent gas station, versus a Shell or Petro-Canada? – Rick, Milford Bay, Ont.

The gasoline sold at independents comes from the same refineries as the gas from the big-name chains – the only difference is that each brand puts in their own recipe of engine-cleaning additives.

"The gasoline sold at any gas station in Canada almost always comes from one of a few well-known refiners," says petroleum industry analyst Michael J. Ervin. "The only difference is that the gas for the national brand gets a proprietary detergent package added at the terminal."

That five per cent of additives is how each brand distinguishes itself, Erwin says. Apart from the additives, the gasoline in any given market is often the same in every station.

"A lot of oil companies share the same terminal," Ervin says. "The gas you buy at a nationally branded gas station may very well not have come from that brand's refiner."

The gas sold at independents still has additives. The Canadian General Standards Board (CGSB) sets minimum standards for the amount of engine-cleaning detergents in gasoline.

"Gasoline sold at no-name or independent stations is generally of the same basic quality as the big name stations," says Daniel Cayley, spokesman with the Ontario Ministry of Energy.

Cayley says all gasoline sold in Ontario must meet federal standards for sulphur and benzene.

The Canadian Independent Petroleum Marketers Association says its members, which include Canadian Tire, Hughes Petroleum and Loblaws, all meet or exceed CGSB standards.

Each company touts their additives, and the majors say they add more additives than the CGSB requires. They say their gas does a better job of keeping deposits from forming on the back side of the valves and in the combustion chambers as the engine runs. For example, Shell says they add nitrogen to basically boost their other additives. Ervin says it's generally believed that the additives are good for your engine, but he hasn't seen any studies that prove that one company's additives are better than another over the life of your vehicle.

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