Altitude favors forced induction. So if you
regularly drive in mile-high altitudes, you'll like a turbocharged rig.
But let's put the supposed power differences into perspective:
A 2001 Excursion Diesel 4x4 makes 250 hp and 520 lb-ft torque, and weighs 7800 lbs
A 2001 Suburban 8.1L 4x4 makes 340 hp and 455 lb-ft torque, and weighs 6300 lbs
The Suburban has to move 18.5 lbs per horsepower (6300/340)
The Excursion has to move 31.2 lbs per horsepower (7800/250)
69% more weight for each horsepower (no matter how it is loaded, all the way up to max GCWR)
Advantage, Suburban.....and why the Sub is 3 seconds quicker 0-60mph
The Suburban has to move 13.8 lbs per lb-ft (6300/455)
The Excursion has to move 15.0 lbs per lb-ft (7800/520)
Advantage, Suburban....even though the Diesel makes more torque
At sea level, it's not much of a contest
Towing a 7000 pound car trailer at 6000 feet (Denver, CO) should certainly favor the Excursion, right? A naturally aspirated motor loses ~3% per 1000 feet where a turbo motor theoretically stays the same.
The Suburban has to move 49.0 lbs per horsepower (6300+7000)/(340*0.80)
The Excursion has to move 59.2 lbs per horsepower (7800+7000)/(250*1.00)
Advantage, Suburban....even loaded, even at altitude
The Suburban has to move 36.5 lbs per lb-ft (6300+7000)/(455*0.80)
The Excursion has to move 28.5 lbs per lb-ft (7800+7000)/(520*1.00)
Advantage, Excursion
However, both horspower and torque are important when towing on the freeway. Torque means you can move the load, horsepower dictates how quickly. The diesel doesn't win hands down. I doubt you've driven a 8.1L GM. Or any number of the newer gas motors.
Moral of the story? If you live in Denver, or frequently traverse 10,000 ft elevations towing your trailer over mountain passes, by all means buy a turbocharged vehicle (in this case, a turbodiesel). But for the rest of us who live and drive in 85th percentile US altitudes, the 8.1L Sub should out-perform a 7.3L Diesel Excursion with the same trailer behind it.
I realize it is "conventional wisdom" that a diesel is somehow better. And it should be, the diesel option adds several thousand dollars over the price of a gas models. In the specific case of the Suburban versus the Excursion, the "weight" of the matter is insurmountable. We all sing praises of lightweight sports cars but somehow think the laws of physics change when we're talking about trucks. The Excursion was the only "modern" SUV available with a diesel. So if you're sold on the idea of a diesel, you'll be sold on the idea of an Excursion.....because it's your only choice.
Diesels are very expensive right now. Illogically so. A 2001-2003 Diesel Excursion (the "good" one with the 7.3L) is $10,000 more than an otherwise comparable 2001-2003 Suburban 8.1L. Fred mentioned that his diesel gets about 30% better fuel economy than his gassers did. That's about the same anecdotal info you'll find all over the net (20-40%). At that rate it would take more than ten years to offset the initial purchase price. The same exact people who would jump all over a hybrid gas-electric (or, heaven forbid, pure EV) with that same logic somehow defend the diesel's outrageous purchase price. Hypocritical, I think.
Don't get me wrong, I love modern diesels. I've owned them all, and the new ones are incredible performers (400 hp? 800 lb-ft? Sign me up). But to pay $20K for a ten year old diesel Excursion with 120K miles makes sense only to those who think they "need" a diesel SUV, rationalize their only choice as the best choice.
Ford : Excursion POLICE PKG Ford : Excursion POLICE PKG | eBay
Yes the later diesel-only Excursions had an increased 9,200 lb GVWR
Suburban 2500s make do with 8,600 lb GVWR
Even so, the Sub will haul, hold, and tow more.