This is a simple hypermiling test. Take a 2017 Chevrolet Cruze Diesel, turn off the A/C, keep the windows rolled up, get on a California freeway, set the cruise control at 55 mph (10 mph under the limit), and see what sort of fuel economy results. Touch the brakes and throttle as little as possible, and return with a mileage number.
In May, we published an instrumented test of a nearly identical Cruze Diesel automatic and reported on how it performed on C/D‘s usual highway fuel-economy loop?200 miles at 75 mph over the Michigan flatlands. As Joseph Capparella reported, that Cruze returned a thick 52 mpg, delivering a beat down to the Toyota Prius by a 6-mpg margin on a loop designed to be a ?real world? test, not optimized for ultimate parsimoniousness. This time, we (by which I mean me) would actually try to get good mileage. So I acquired a Cruze Diesel sedan practically identical to what Capparella had reviewed. Both had the 137-hp, aluminum turbo-diesel 1.6-liter inline-four, both wore 16-inch wheels wrapped in Goodyear tires, and both had the optional nine-speed automatic transmission.

On the ninth day of June, a Friday, the slate-gray Cruze was filled at pump 5 at the Winchester 76 in Goleta, California. The tank was topped off until the automatic stop on the pump handle snapped itself off twice (in between, it was left to rest for 10 seconds while fuel settled in the tank). Winchester 76 was chosen because it pumps diesel, it?s at the far northern edge of the...