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Say SUV and what pops into mind? “Fuel hog and hard-to-drive,” or “Go for it"? No matter which side you’re on, perhaps second impressions hold more staying power—especially since GM has flexed the fuel power of their largest SUV. With a base price of $40,435, our Sport Red Metallic test model was priced at $45,610. Equipped with the 5.3L Vortec V-8 engine with Active Fuel Management and flex-fuel capability, it earns EPA ratings of 15 mpg city/20 mpg highway with 310 horsepower. Could this SUV overcome a bad first impression lingering from the 90’s full-size ute fever?
Initial Impression: Earth destroyers en guard
Christine: “Having scheduled this test drive months in advance, I noted the Suburban was due to arrive this week yet I wasn’t particularly enthused. Can’t say I was looking forward to tooling around in the biggest SUV. However, a step into the driver’s seat proved this might not be such a painful week after all—and then we needed to make a trip to the beach and have trailer-hauling ability. That Suburban wasn’t lookin’ too bad after all. Yet I couldn’t help but wonder if one of my friend’s queries would prove true: ‘Don’t you get dirty looks when you’re driving a Suburban?’”
Scott: “I’ve never been fond of outrageously large SUVs. I’ve always thought of them as inefficient lumbering land yachts that handled like a school bus and parked like a 747. But, after just a few miles behind the wheel, my harsh judgment fairly tempered and I began to understand why these big guys have such appeal.”
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Look & feel: Comfort central
From the charcoal leather seating to the tri-zone climate control, there isn’t a passenger that’ll be uncomfortable in this ride—all seven of them. We hoped the kids and their grandparents could pile into the double-row rear seating for a day out and no one would feel the pinch. We weren’t disappointed. With 137.4 cubic feet of cargo room behind the first row seats, we had plenty of space for all that beach stuff. The nifty rear lift window gave handy access to the cargo space too. We made good use of the 8,200 pound towing capability and hooked up a trailer to tow a lawn tractor back home for repair.
Scott was extremely surprised at the Suburban’s agile handling and the quality of the ride on its 130-inch wheelbase. Actually, we all enjoyed the benefit of the new coil-over-shock front suspension design and rack-and-pinion steering. In fact, Scott’s parents commented repeatedly at what a super vehicle it was—it certainly didn’t hurt that we had taken them out for an evening on the town, complete with steak and buffet dinner. And they weren’t even privy to GM’s new full-size SUV platform info: the fully-boxed frame, the premium interior system and streamlined aerodynamics—that fortify a quiet traveling experience.
While we give you the low-down on the "alt fuelness" of the Burb, be sure to check out SUV Guide Jason Fogelson's review of the 2007 Chevrolet Suburban for more of this SUV's driving impressions.
Fuel-ability: Mannerly, but not miserly
It’s a full-size SUV with a 5.3-liter V-8 to tow trailers and haul cargo and people. It boasts 310 hp and 335 lb.-ft. of torque. But it’s a compromise, really—all that power generated by that big V-8 isn’t always needed, and is often wasted under most cruising conditions. GM, however, took this waste to task by developing Active Fuel Management, their version of cylinder deactivation that shuts down half of the engine’s cylinders under light load conditions.
It’s like getting two engines in one. The full V-8 power is available, but it can switch to what amounts to a V-4 under light load cruising conditions. Depending upon driving conditions and fuel needs, sensors signal the computer to deactivate four cylinders when conditions warrant. As soon as the accelerator is pushed a bit harder, the valves and fuel flow to those cylinders are reactivated. Under ideal conditions, this system can improve fuel economy between 12 and 15 percent. Sure, that’s a good thing, but we’d like to see even more improvement.
And that gave Scott an idea—that the Active Fuel Management with flex-fuel capability should have the intelligence to adjust fuel injector pulse width (how long the injector fires), according to power requirements. With simpler flex-fuel management systems, the injector pulse width is increased to provide more fuel per injection—this is designed to overcome the power disadvantage that ethanol has to gasoline. If a more sophisticated systems was employed, and the engine did not warrant increased injector pulse width, it could be curtailed—increasing the fuel economy of E85.
The Enviro-meter: Reality check
The aluminum-block Vortec 5.3L V-8 is compatible with ethanol-based fuel, gasoline, or any combination thereof. Accumulating a good amount of highway miles on our trip to the beach, and after initially driving on straight gasoline, we topped off the 30.5-gallon tank with E85 twice. After one week and 420 miles, our average mileage rang in at 15.4 mpg, including substantial trailer towing. We bet some of GM's improvements, say the more steeply raked windshield and tighter tolerances and front-end sealing, help to eek out better fuel economy.
We applaud the flex fuel system. We applaud the Active Fuel Management. But we do think there's still a lot of room for clever engineering to lessen the fuel-thirsty appetite of these big vehicles. Yes, we'd even like to see the relatively simple addition of a 5 or 6-speed overdrive automatic transmission to boost the highway fuel mileage.
Crunchin' the greenhouse gas numbers: the fuel of choice will determine the environmental impact. According to fueleconomy.gov, drive 15,000 miles per year on E85 and your energy usage will be equivalent to 6.7 barrels of crude annually--compared to 24.5 barrels for a conventionally fueled Suburban. However, choose to fill 'er up with higher percentages of gasoline, and you'll raise that 6.7 to 21.4. It's all in the fuel ratio. Likewise, greenhouse gas emissions for using E85 tally up to 9.2 tons/year, where the regular Suburban will spew out a higher 13.1 tons/year. And using a blend of E85/gasoline comes in at 11.4 tons/year.