30 MPG Highway in a 5.0-Liter 2015 Mustang GT?

Every time a Ford Mustang rolls into my driveway it feels like an old friend has come to visit. While I’ve never owned a Mustang, I’m reminded by all of the good times I’ve spent riding in pony cars and the great folks I’ve come to know along the way. So when the chance to test the 2015 Mustang GT appeared, there was no hesitation. After putting over ten thousand miles on Slambo (my 1999 Honda Civic HX fuel economy project car), I was more than ready to drive something with a healthy dose of horsepower under the hood.

The 2015 Mustang is available with three engines:

• The 5.0 liter V8 cranks out 435 horsepower and 400 foot pounds of torque when running on 93 octane premium, although the engine is engineered to run on 89 octane regular. It’s EPA rated to deliver 16 miles per gallon (MPG) in the city, 25 miles per gallon on the highway, and 19 combined.
• The base 3.7 liter V6 produces a respectable 300 horsepower and 280 foot pounds of torque. The V6 automatic fastback is EPA rated at 19 city, 28 highway, 22 combined.
• The 2.3 liter EcoBoost four churns out a very healthy 310 horsepower and 320 foot pounds of torque on 93 octane fuel, like the V8, the EcoBoost four is spec-ed to run on regular. The automatic fastback carries an EPA rating of 21 city, 32 highway, 25 combined.

I tested a 5.0-liter Mustang GT, equipped with an automatic transmission. While manual transmission GTs are equipped with launch control, automatics are not. I took two 0-60 runs, from a standing stop. I smoked the tires bad on the first run. A little too much spin on the second run landed a 5.1. When all things are right and there’s 93 octane fuel in the tank, the GT should be good for the mid to high fours in stock form.

While I fell a bit short on the acceleration test, fuel economy was a whole different story, with an combined average slightly over spec. (I freely admit to giving into the temptation under the hood.) But the highway mileage knocked me out. After more than forty miles of highway testing at a target speed of 68 miles per hour, I averaged slightly over 30 MPG while running under cruise control. I’m pretty sure I could squeak a bit more out of it, without cruise.

– by Daniel Gray