When engine designs only ‘recommend’ premium for a vehicle, cost outweighs benefit
BOISE – (December 12, 2017) – Although vehicle owners should always follow manufacturer directions when premium fuel is required, drivers that pay for premium when it’s only “recommended” don’t see significant performance gains, according to AAA’s recent study.
“When an engine is exclusively designed for premium, the system and fuel are closely calibrated for max efficiency,” says Matthew Conde, public affairs director for AAA Idaho. “But when premium is only recommended, the vehicle’s engine has to accommodate lower-octane fuels, which means that from a design standpoint it isn’t optimized to get the full benefit of higher-octane gas.”
It’s a clear-cut case when premium fuel is required, but AAA wanted to explore the gray area surrounding “premium recommended” vehicles. How big of a benefit could drivers get for the extra expense?
AAA’s study identified six vehicle types labeled by manufacturers as premium recommended. Based on study results, owners of these vehicles are unlikely to see any major benefit from using premium gasoline for typical city or highway driving, so the vehicles were also exposed to more extreme driving scenarios such as towing, hauling cargo, and aggressive acceleration.
When using premium fuel under these extreme conditions:
- Fuel economy for test vehicles improved by a modest 2.7 percent. Individual vehicle test result averages ranged from a decrease of one percent (2016 Audi A3) to an improvement of 7.1 percent (2016 Cadillac Escalade)
- Horsepower averaged an even smaller increase of 1.4 percent. Test result averages ranged from a decrease of 0.3 percent (2016 Jeep Renegade) to an improvement of 3.2 percent (2017 Ford Mustang)
“There are marginal horsepower benefits for heavy towing and performance enthusiasts, but it all depends on the vehicle,” Conde said. “In cases where premium is only recommended, drivers can purchase lesser grades of fuel and compare overall performance based on their unique driving circumstances, such as commutes, vehicle use, and area road conditions. Unfortunately, any performance gains will likely be offset, and then some, by the higher price of premium gas.”
AAA reminds motorists that failure to use premium fuel when it is required can result in vehicle damage that may not be covered by the manufacturer’s warranty. Consult the owner’s manual to see what is recommended, and what is absolutely required. The compartment by the fuel door, or gas cap, may also provide this information.
The growing price of premium
“The gap between premium and regular gas has been steadily rising since 2009, with the most dramatic increase occurring in the last two years,” Conde said. “Historically, premium fuel cost about 10 percent more than regular unleaded. Since 2016, the price difference has jumped into the 20 to 25 percent range.”
Today, the U.S. average price for a gallon of premium gas is $3.01, which is 55 cents more than a gallon of regular. Here in the Gem State, the price of premium is $3.07, which is 47 cents higher than regular.
“The price of premium fuel can vary widely, even from station to station in the same town,” Conde said. “It’s a good idea to shop around.” The AAA mobile app (available on Apple or Android) locates the cheapest gas in the area using search filters that can be adjusted for premium and other fuel types.
AAA advises potential vehicle owners to factor fuel into the cost of vehicle ownership, particularly if it requires premium.
Which fuel is right for my car?
“If a premium-recommended vehicle makes a knocking or pinging sound with a lower-octane fuel, consider stepping up the level until the sounds go away,” Conde suggested. “If that doesn’t work, take the vehicle to a trusted repair shop for a closer look.”
During the course of its recent study, AAA found multiple owner’s manuals for premium-recommended vehicles that specified the use of no lower than 87 octane when using regular gasoline. That would disqualify the 85-octane fuel found in some mountain states, including Idaho. Check your owner’s manual to find the appropriate octane requirements.
Previous AAA fuel research
In late 2016, a AAA study found that purchasing premium fuel is not a ‘treat’ for a vehicle that requires a lesser grade, and that Americans spent $2.1 billion on unnecessary gas upgrades the previous year.
Another AAA study found that there is a decided difference in quality between TOP TIER-rated fuels and other products. TOP TIER detergent and additive packages led to 19 times fewer engine deposits than non-TOP TIER fuel.