TRAVERSE CITY, MI – Makers of compact cars aspire to deliver 40 mpg (5.8 L/100 km) these days, and fuel prices now topping $4 across much of the state certainly validate the goal.

General Motors bills its Chevrolet Cruze Eco as delivering 42 mpg (5.6 L/100 km) on the highway with an iron-block internal-combustion engine that has nary a trace of hybrid technology.

We put the claim to the test as we drove here for the Center for Automotive Research’s Management Briefing Seminars – a 250-mile (402-km) jaunt.

Dashboard average fuel economy readings at 50-mile (80-km) intervals along the interstate range from 39.7 mpg (5.9 L/100 km) at the early part of the journey, with more city driving, to 43.5 mpg (5.4 L/100 km) along the homestretch.

Yes, the Cruze Eco exceeds the Environmental Protection Agency’s rating that appears on the window sticker.

The port-injection turbocharged 1.4L DOHC 4-cyl. engine produces 138 hp and 148 lb.-ft. (2019 Nm) of torque, and the Cruze Eco can be had for less than $20,000.

In striving for greater fuel efficiency, GM engineers cut the weight of the Cruze Eco by using lighter wheels and thinner sheet metal in certain areas and a tire-sealant and inflator kit that replaces a jack and spare.

We offset those weight-reduction efforts by stuffing the trunk with an over-packed suitcase and a set of golf clubs.

And an imponderable happened along the way: An SOS call from fellow editor Byron Pope, whose Dodge Dart press car left him stranded near Flint.

The instrument panel was flashing a warning not to drive the pre-production car. Engineers are looking over the Dart in question today.

Long story short, the little 3,011-lb. (1,365-kg) Cruze Eco came to the rescue. The compact ended up carrying the additional weight of a passenger and his traveling gear.

And despite that extra mass, the car achieved its best fuel economy.

Driving slower during the last leg of the journey certainly helped the cause. We even got into the spirit of hyper-miling by gingerly using the accelerator and passing only the slowest vehicles, such as a beat-up Ford Ranger pickup piloted by an older woman sporting a large tattoo on her left arm that dangled out the window.

It feels good to get great mileage, such as 40.6 mpg (5.8 L/100 km) on the expressway while passing the former Buick City factory complex in Flint. It is the home of the old V-8 engine that got 15 mpg (15.6 L/100 km) on a good day.

Of course, back then gasoline was $0.25 a gallon. Those were and weren’t the good old days.

Incidentally, Flint now produces GM’s 1.4L turbo I-4 that powers the Cruze Eco.

sfinlay@wardsauto.com