Silvio Calabi: Summit Diesel tops Jeep’s Grand Cherokee range
For a long time I’ve touted modern diesel car engines as efficient, smooth, quiet, cold-proof and clean-running. Then I had to backtrack on that last bit with VW diesels. And now, for the oil-burning version of Jeep’s highly regarded Grand Cherokee, I have to make another retraction. Despite its modern architecture — overhead camshafts and 24 valves — this 3.0-liter diesel V-6 sounds old-school. It rumbles and grumbles, and in late May its glow plugs need to warm up before it’ll start in the morning.
But there’s no harsh diesel clatter to make us wince, so we can tolerate and possibly even appreciate the engine growl. It reminds us that we’re driving something different — something that might be harder-working and (Grrr) tougher than a mere gas SUV, never mind some eco-weenie hybrid or suburban electric mom-bomb.
Nothing against those things, and I’m a bit of an eco-weenie myself, but whatever effect Jeep is trying to create here, they’re delivering both power and efficiency. This full-size 4X4 is rated for 28 mpg on the highway and 24 overall, with a hypothetical range of more than 700 bladder-straining miles per tank. (In 260 mostly fast miles, we averaged an indicated 27 mpg. A diesel Grand Cherokee with the front air dam — not available on this Summit — should do 30 mpg highway.) Yet its engine makes 240 horsepower and 420 torques, and — with the included heavy-duty alternator, battery and brakes — can tow up to 7,400 pounds. The eight-speed automatic transmission shifts smoothly underway, but launches take some practice. There’s a hesitation and then, just as you add more throttle, the transmission suddenly hooks up and off you lurch. For everyday driving, one of the Grand Cherokee’s two available gasoline drivetrains responds better; the diesel seems to be more of a workhorse.
But this is not only a torquey and relatively fuel-efficient workhorse, it’s also a luxurious one, especially in range-topping Summit trim. Short of the latest Cadillacs, this leather and wood-swathed cabin is as nice as it gets in Detroit, and overhead there’s an acre of power sunroof. The Summit model also has a killer Harman Kardon stereo with a 12-channel amplifier, three subwoofers and 19 speakers, and noise-cancelling technology. (It doesn’t cancel diesel rumble.) The front seats do the usual tricks, and the driver gets two memory settings and auto-retract plus steering-wheel heat. The back doors are small, but those seats are heated too, and their backs adjust through 24 degrees. Between them and the power liftgate is useful space and a cubby with hooks for grocery bags. The spare tire compartment includes two removable bins for muddy gear or things to hide.
Utility in a Jeep also means 4WD and off-roadability. Our Summit has Jeep’s Quadra-Drive II 4X4 system with Selec-Terrain and Quadra-Lift. Translation: High and low gear ranges plus a limited-slip rear differential, and the ability to send engine torque to whatever wheels have grip.
Selec-Terrain coordinates a dozen different powertrain, braking and suspension settings for best behavior on sand, mud, snow, rock or pavement. And Quadra-Lift means inflatable air springs at each corner that deliver, automatically or manually, five height settings spanning 3.8 inches of lift, for aerodynamics, ground clearance or easier in and out. Oh, and there’s Selec-Speed, too.
This lets drivers control the Grand Cherokee’s pace up and down steep grades just with the shift paddles — throttle and brake not needed. Hill-descent control even works in reverse. Out in the tules, these features help the Summit make the most of its steep approach and departure angles. (That’s why there’s no front air dam.)
For 2016, more than a dozen 4WD systems are available across six Jeep model lines, but fear not — they’re clearly explained on the improved Jeep.com site.
We haven’t even mentioned our Summit’s new active safety systems, or its digital apps, but they’re all here (including $1,290 worth of skid plates and trim and a $5,000 premium for the diesel engine) at an MSRP of $59,880. This means that a very well equipped top-end Grand Cherokee lists for about as much as a similar-size but bare-bones Range Rover. And going in the other direction, a Grand Cherokee can theoretically be de-contented all the way down to a 2WD Laredo for just $29,995. Bravo, Jeep.
— Silvio Calabi reviews the latest from Detroit, Munich, Yokohama, Gothenburg, Crewe, Seoul and wherever else interesting cars are born. Silvio is a member of the International Motor Press Association whose automotive reviews date back to the Reagan administration. He is the former publisher of Speedway Illustrated magazine and an author. Contact him at email@example.com.
— A hundred grand worth of the Euros’ toys for $60,000
— On-road comfort, off-road aptitude
— Impressive fuel efficiency for a heavy-duty SUV
— Diesel rumble
— Hesitation on launch
— Screen and graphics are a generation behind
— Diesel rumble