Many drivers who make this choice are wasting money

You could be among the drivers who collectively waste $2.1 billion a year on premium gas even if it is recommended for your car.

A new report from AAA shows that it pays to know if high-octane gas is required or recommended for your car, and then to evaluate the benefits accordingly.

While you should buy premium gas if it’s required, the nonprofit AAA found that the added benefit generally doesn’t outweigh the higher cost when premium gas is only recommended.

This news comes as the difference between the costs of regular-grade and high-octane gas has reached about 25 percent — up from a historically steady 10 percent. Based on national averages, premium gas now costs about 50 cents more per gallon.

Putting premium gas to the test

For its report, AAA worked with the Automobile Club of Southern California’s Automotive Research Center to test various cars for which premium gas — 91 octane or higher — is recommended but not required. The cars were tested in a laboratory and on the road.

AAA says drivers of such vehicles are unlikely to see a benefit from using premium gas during typical city or highway driving. But the organization wanted to determine whether those drivers would see a benefit in extreme driving situations like:

  • Towing
  • Hauling cargo
  • Aggressive acceleration

Here’s what AAA found when running these tests on cars for which premium gas is only recommended:

  • On average, fuel economy improved by 2.7 percent. Looking at the individual car models tested, fuel economy changes ranged from a decrease of 1 percent for the 2016 Audi A3 to an increase of 7.1 percent for the 2016 Cadillac Escalade.
  • On average, horsepower improved by 1.4 percent. Looking at individual models, horsepower changes ranged from a decrease of 0.3 percent for the 2016 Jeep Renegade to an improvement of 3.2 percent for the 2017 Ford Mustang. 

RELATED: Here's what some of your older cars are worth now:

12 PHOTOS
what your old car is worth now
See Gallery
what your old car is worth now

1960 Ford Bronco 
Asking Price: $149,000

Photo credit: eBay.com

1953 Cadillac Coupe De Ville 
Asking Price
: 55,500 

Photo credit: eBay.com 

2006 Hummer: H1 
Asking Price: $249,888

Photo credit: eBay.com 

1956 Ford Thunderbird 
Asking Price: $39,900

Photo credit: eBay.com 

1970 Buick Other GS 
Asking Price: $145,000

Photo credit: eBay.com 

1965 Ford Mustang Fastback
Asking Price: $275,000

Photo credit: eBay.com 

1983 Land Rover: Defender 
Asking Price: 159,900

Photo credit: eBay.com 

2005 Ford GT  
Asking Price: $345,000

Photo credit: eBay.com 

1965 Chevrolet Impala 
Asking Price: $144,990

Photo credit: eBay.com 

1935 Mercedes-Benz 500-Series  
Asking Price: 1,995,900 

Photo credit: eBay.com 

1969 Porsche 911 
Asking Price: $138,100

Photo credit: eBay.com 

1991 BMW M3 
Asking Price: $130,000

Photo credit: eBay.com 

HIDE CAPTION
SHOW CAPTION
of
SEE ALL
BACK TO SLIDE

 

Weighing the cost and benefits of premium gas

Based on its testing, AAA concluded that the “modest” improvements seen with premium gas do not offset the fuel’s higher price.

John Nielsen, AAA’s managing director of Automotive Engineering and Repair, explains:

“There’s no question that higher-octane premium fuel has the potential to boost a vehicle’s fuel economy and performance. However, engines have to be calibrated to require that fuel to see the full benefit.”

In other words, if premium gas is recommended rather than required for your car, the vehicle can’t take full advantage of the benefits of premium gas.

So, AAA’s recommendation is to always use premium gas if it’s required, but to buy regular gas if premium gas is only recommended.

If your car makes a pinging or knocking noise on regular gas, however, you should have it checked out by an honest and qualified mechanic and probably switch to premium gas, AAA says.

If you just want a higher-quality gas than regular, consider Top Tier gas.

Premium versus Top Tier gas

Regular, premium and Top Tier gas are three different types of fuel.

Premium gas has a higher-octane rating than regular gas, while Top Tier gas has more detergent additives than federal standards require. Research conducted by AAA last year found that Top Tier gas keeps engines up to 19 times cleaner — meaning more free of engine deposits.

To learn more about the benefits of Top Tier gas, check out “AAA Urges Drivers to Pay Extra for Top Tier Gas.”

What has your experience been with premium versus regular gas? Share with us by commenting below or on Facebook.

Read Full Story