Fuel Economy Update for September - Track Day, New Exhaust Drop MPG Average - 2015 Ford Mustang GT Long-Term Road Test

2015 Ford Mustang GT Long-Term Road Test

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2015 Ford Mustang GT: Fuel Economy Update for September - Track Day, New Exhaust Drop MPG Average

by Carlos Lago, Road Test Editor on October 8, 2015

2015 Ford Mustang GT

You can almost hear Captain Obvious: "If you wanted better fuel economy from your 2015 Ford Mustang GT, you shouldn't have optioned it with a 3.73 rear end, installed a loud exhaust, and taken it on a track day!"

Our Mustang covered 1,706 miles in September and consumed 118.2 gallons of high-octane gas, making for a 14.4 mpg month average. That's the third lowest we've recorded in our 10 months of ownership.

What happened?

Mike Monticello took it up to Mazda Raceway Laguna Seca and drove it really fast. In the process, he netted both the worst and second-worst fuel economy we've ever recorded: 5.3 mpg over 81.2 miles on a Saturday and 9.1 mpg over 100.9 miles the following day. Good job, Monticello.

The new, wonderful Ford Racing exhaust has inspired the team to drive a bit more enthusiastically, compounding the "I need to rev more" effect our 3.73 rear end has had on us since Day One.

The average tank fill has settled at around 200 miles. Josh Sadlier noted the low-ish range numbers, a product of the aforementioned final drive, and wondered if enlarging the Mustang's 16-gallon fuel tank would be worth it. Travis Langness compared our GT to a Mountune-modified Focus ST that visited our office, comparing the performance deficit to the roughly $10,000 price difference.

I simply want our orange GT to handle better. Stay tuned: The Ford Racing suspension install happens soon. This also doesn't bode well for future fuel economy results.

Worst Fill MPG: 5.3 
Best Fill MPG: 23.5 
Average Lifetime MPG: 15.8
EPA MPG Rating: 19 Combined (15 City/25 Highway) 
Best Range: 321.6 miles 
Current Odometer: 15,530 miles

Carlos Lago, Road Test Editor @ 15,530 miles

  • Full Review
  • Pricing & Specs
  • Road Tests (2)
  • Comparison
  • Long-Term

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