Does the Brand of Gas I Use in my Car Actually Matter?

It actually does matter; some brands of gasoline contain more detergent additives that can prevent carbon deposits from forming inside your engine.

In 2004 auto makers were concerned that existing gas did not have sufficient levels of additives and detergents to prevent carbon buildup in modern automobile engines. In recognition of this they created what is called The TOP TIER standard for gasoline. Modern automobile engines are more likely to operate with higher compression, turbo charging and variable valve timing. TOP TIER additives are added into tanker trucks prior to leaving for delivery to gas stations, and even the smallest independent mom-and-pop station can order its shipments to meet TOP TIER standards if it chooses.

To test whether TOP TIER gas is actually better for engines, AAA ran both TOP TIER gas and gas that meets the federal government’s 1996 minimum standards through an engine for 100 hours (simulating 4,000 road miles). The tests found that the TOP TIER gas produced 19 times fewer intake valve deposits than the minimum-standard gas, AAA reported.

Most of the major oil companies have embraced the voluntary Top Tier standards for detergent additives, this includes Amoco, BP, Chevron, Citgo, Costco, Exxon, Marathon, Mobil, Shell, Sunoco, Texaco and Valero.

Vehicle manufacturers claim that using other brands of gas may over time allow carbon deposits to form in combustion chambers, this can cause engine knock or pinging (premature fuel ignition) on intake valves, which can impede valve operation.

This doesn’t mean you should never use anything except a rated Top Tier gasoline. For some motorists, the nearest Top Tier station may not be close by, it may be miles away, making it impractical to fill up at those gas stations consistently. Sometimes you have to take what you can get in a specific situation.

Some vehicle manufacturers suggest that owners who don’t use Top Tier gasoline add a fuel-system cleaner to their tank periodically to clean out any deposits or gunk that may have developed. You should first check your owner’s manual to see what your car manufacturer recommends about Top Tier gas, gasoline and octane ratings as well as fuel additives.

We recommend using gasoline from a Top Tier company as often as is practical and economically feasible, plus periodically adding a high-quality fuel system cleaner if you often use other brands of gas, should do the trick. If you have questions about what you should be using please don’t hesitate to ask our technicians.