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  • Fuel Economy - The Debate Marches On

Fuel Economy - The Debate Marches On

All Bets Are Off, The Definitive Answer

Dan Ward
Feb 1, 2006
Photo 2/2   |   fuel Economy ford F250
Six years ago, the debate on which one was better to own, gas or diesel, was a moot point. Truck buyers before the turn of the millennium could not have cared less about diesels unless a fifth wheel was involved or farming purposes required a heavy hauler. Overtly loud rigs, horrible emissions, and poor fuel economy hampered previous diesels; however, with new diesel technology better than ever-and just scratching the surface of its potential-truck buyers have a valid choice between engine and drivetrain setups. Problem is, depending on whom you talk to, the choice isn't completely black and white. We're going to try our best to make it that way with this in-depth look inside the basics of gas versus diesel.
First things first: There are several key factors to seriously think about before signing on the dotted line. Gas engine technology is also on the rise with Displacement on Demand, throttle-by-wire, and hybrids being developed and employed in Chevrolet, Ford, Toyota, and Dodge trucks alike. Despite all of these advancements, the core of any manufacturer's truck line is the general-purpose, tow-and-haul heavy-duty line that typically doesn't incorporate many of these technologies because of the lack of demands from the EPA for gas mileage statements. With the absence of pressure to create high fuel mileage numbers for consumers, manufacturers can focus on the numbers that do count to these buyers: horsepower, torque, and towing capacity.
Another key factor is examining the current price of fuel from coast to coast. Diesel costs have not seen a plateau, like that seen with gasoline, since the horrible hurricane disasters. Currently, diesel prices are a full $.94 more a gallon than they were only a year ago. One big reason for this rise in diesel price and decline in gasoline price is the seasonal change. Distillate fuels used for heating are very similar in makeup to diesel fuels that are used on the highway and with temperatures dropping, costs are rising. Simple economics? Not really, because even if the supply is close to meeting the demand like the current gasoline trend, diesel, with its industrial uses, may not see a dip in prices. Making matters even worse for those of you in the colder climates, diesel prices are oftentimes a full $1.30 more a gallon than premium gasoline during this time of the year.
One of the most important factors to take into consideration is truck usage. If towing your toys and hobbies is an every weekend affair and your particular trailer is in excess of 9,000 pounds, then a diesel may very well suit your needs; however, if a short stint every once in a while is typical, a gas-powered truck could very well meet your needs.
Looking at the pros and cons of each application leaves only dust to settle because this issue truly is closed. This comparison is based on 3/4-Ton Crew Cab 2WD trucks with the largest available small-block V-8 gas-powered engine (excluding the GM 8.1L) and the same configuration with the available diesel engine with automatic transmissions.
Gas-Powered Trucks
* Lower Initial Cost
* Lower Fuel Cost
(at time of this editorial)
* Cheaper Aftermarket Parts
* Cheaper Replacement Parts
* Gas
Pumps on Every Corner
* Technology on Rise for Better Mileage
* Strict State-to-State Emission Laws
* Cost of Parts Required to Equal Base Diesel Performance
* Less Heavy-Duty Parts from Factory
* Premium Fuels Varyfrom State to State
* Excessive Wear of ComponentsWhen Towing
Diesel-Powered Trucks
* Huge Towing Capacity
* More Heavy-Duty Parts from Factory
* Upgrades Can Turn Your TruckInto a Pulling Factory
* Technology Just Startingto get Intelligent
* Current Emission Exemption
* Huge Initial Cost
* Booming Seasonal Diesel Prices
* Aftermarket Parts CostMore than Gas Parts
* Adding More Boost MeansSomething Will Break
* Emission Restraints In the Works
* Replacement Parts Costly
* Finding A Pump Can Be Challenging
Take A Close Look At This Comparison
Chevrolet Silverado 2500HD Crew Cab 2WD
Base Price: $31,030
Engine: 6.0L Vortec V-8
Horsepower: 300 @ 4,400 rpm
Torque: 360 @ 4,000 rpm
Towing: 10,100 lb
Fuel Capacity: 26 gal
Estimated 12-month Fuel Cost*: $2,600
Base Price: $36,340
Engine: 6.6L Duramax V-8
Horsepower: 310 @ 3,000 rpm
Torque: 605 @ 1,600 rpm
Towing: 12,000 lb
Fuel Capacity: 26 gal
Estimated 12-month Fuel Cost*: $3,150
Dodge Ram 2500 Heavy Duty Quad Cab 2WD
Base Price: $28,985
Engine: 5.7L HEMI V-8
Horsepower: 345 @ 5,400 rpm
Torque: 375 @ 4,200 rpm
Towing: 9,050 lb
Fuel Capacity: 34 gal
Estimated 12-month Fuel Cost*: $2,600
Base Price: $35,590
Engine: 5.9L Cummins I-6
Horsepower: 325 @ 2,900 rpm
Torque: 610 @ 1,600 rpm
Towing: 13,300 lb
Fuel Capacity: 34 gal
Estimated 12-month Fuel Cost*: $3,150
Ford F-250 Super Duty Crew Cab 2WD
Base Price: $27,570
Engine: 5.4L Triton V-8
Horsepower: 300 @ 5,000 rpm
Torque: 365 @ 3,750 rpm
Towing: 9,600 lb
Fuel Capacity: 29 gal
Estimated 12-month Fuel Cost*: $2,600
Base Price: $32,670
Engine: 6.0L Power Stroke V-8
Horsepower: 325 @ 3,300 rpm
Torque: 570 @ 2,000 rpm
Towing: 12,500 lb
Estimated 12-month Fuel Cost*: $3,150
*-> 12-month fuel cost estimate based on average price of regular unleaded and average price of diesel, fuel tank capacity, and a yearly maximum of 15,000 miles. Regular unleaded price used, $2.60 and diesel price $3.15. Based on15 mpg, towing not factored in mileage.
Besides the side-by-side comparisons of price, power, and towing, other factors in the equation include wear, aftermarket potential, and mileage.
With a gasoline-powered truck, even in the heavy-duty lineup, most drivetrain parts, including transmission, cooling system, driveshaft, rear end, bearings, and brakes, are of lesser strength than the comparable diesel counterparts. On the flip side, diesel trucks do weigh more than gas-powered trucks and do take longer to slow and come to a stop. Stopping is crucial with larger trucks, especially when towing and with several manufacturers offering trailer brakes as an option, diesels may have a slight advantage with their heavy-duty original equipment.
Aftermarket potential is an interesting topic, because this is where the debate gets very heated. Take a Chevy 6.0L, add a $3,750 supercharger, $400 after-cat exhaust, $550 headers, and a $350 programmer and in theory you could make 500hp and 525lb-ft of torque. This $5,050 investment (minus installation) is still $260 less than the Duramax diesel option. Spend the $5,050 on diesel aftermarket parts and in theory you could have a 700+hp and 1100+lb-ft stump-pulling monster on your hands. However, that is $10,100 more than the initial gas-powered stock investment and ten grand is a huge chunk for anyone.
Towing is the final piece of the debate puzzle and here there is a definitive winner: diesels. Because of the crude characteristics of diesels, super-high compression engines are used to maximize power and with most diesels red-lining at or around 3,100 rpm, low-end torque is unbelievable. Huge torque plus low rpm equals towing that is unmatched by any gas-powered truck. With the internals turning at such low numbers, diesels typically last two to three times longer than equally worked gas engines. Towing can really take a toll on gas engines and transmissions because down-shifting and high-revs are part of the workhorse equation.
Sure, people are saying diesel is the wave of the future and crude oil is depleting too quickly for demand, but right now, the debate still rages in the truck world. With the dust settling and all bets off, concluding this debate is easy. If you tow more times than not, go ahead and fork over the additional five grand and get your money's worth. If, however, towing is not necessary Monday through Friday, a gas-powered truck will easily suffice and keep some greenbacks in your pocket.
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