- Diesel engine firm Cummins just revealed its first gasoline-powered engine
- The new “B6.7” is rumoured to be destined for medium-duty Kenworth trucks
- Its turbo’d, runs fine on pump gas, and offers 300 hp and 660 lb-ft in top trim
A name all but synonymous with stump-pulling diesel engines has just launched its first ever gasoline-powered mill. Fetchingly called the “B6.7” (no one said engine-makers were good at coming up marketing) Cummins says it has been specifically designed and developed for the medium-duty market. That means machines like school buses, big delivery vans, and vocational trucks.
It does have a turbocharger, though Cummins notes that (logically) no DEF refills are required. According to charts provided by the company, it seems there will be numerous states of tune, ranging from a low-stress configuration generating just 200 horsepower but 600 lb-ft of torque; all the way up to a 300-pony variant with 660 torques. These ratings are still preliminary.
Cummins hopes for a 10% bump in fuel economy over other gasoline-powered engines, depending on duty cycle. This would be welcome in the medium-duty world, where your author once experienced first-hand the terrifying thirst of a fully laden 26-foot U-Haul moving truck powered by a gasoline engine.
Estimated torque curves show the gasser hitting its stride around 1,600 rpm, depending on the state of tune, compared with a typical Cummins diesel, which is hauling the mail at about 1,200 revs. The gasoline-powered engine continues pulling to its 3,200-rpm redline, at which point the diesel is long since dead and buried. The brand alleges over two million miles of testing.
Who’s the customer for such a mill? It is being reported that Kenworth is launching a line of its medium-duty Class 5 to 7 commercial trucks with this engine. It also could be a boon to fleet owners dealing with machines working in places where access to diesel fuel is not plentiful; this B6.7 runs just fine on plain old regular 87-octane.
Around these parts, the Cummins brand is most closely associated with Ram Heavy Duty trucks, a series of machines long available with straight-six diesel engines behind their increasingly angry grilles. There’s absolutely nothing to suggest Ram is even entertaining the notion of using these mills in its Heavy Duty pickups, though. That automaker’s existing 6.4L Hemi V8 cranks out 410 horsepower and 429 lb-ft of hairy-chested torque.
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