American trucking company exec Ron Hall's job is to know his trucks…inside out.

Actually….no – his knowledge goes way, way beyond that: He knows them in extreme detail.
In order to extract the best fuel economy out of giant Utah carrier C.R. England's fleet, he knows, for instance, exactly what "the sweet spot" is when it comes to diff ratios (2.16:1), engine horsepower (455 horsepower)…and precisely what speed to allow its trucks to run to.

That'll be 65 miles per hour (the equivalent of 104km/h) on cruise control…or 63mph with the foot on the throttle pedal. That's anywhere between five and 20mph lower than legal limits across the US.

He knows that running super-single tyres might help fuel economy…but they don't stack up when it comes to return on investment. Understands that driver-facing cameras might help reduce accidents (or they might 

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