Whatever you may think of basketball superstar Shaquille O’Neal’s popular rap album, “Shaq Diesel,” it doesn’t smell or belch soot. And the noise can be controlled with a volume knob.
It’s never been that easy to get along with diesel trucks.
But just as giant steps have been taken in cleaning up exhaust from gasoline engines, today’s light-duty truck diesel engines run much cleaner. And like “Shaq Diesel,” which recently sold its 1 millionth copy, diesel trucks are posting some pretty impressive numbers.
About 155,000 of the 1.1 million full-size pickups sold last year came with diesel engines.
They’re especially popular with construction foremen, farmers, ranchers and hobbyists with heavy things to tow, such as boats, campers and horse trailers. Diesels provide lots of muscle to get rolling and loads of horsepower to keep moving.
The Big Three automakers, strapped to build enough gasoline-powered trucks to meet a seemingly unquenchable demand, are trying to one-up each other in the diesel business.
Market shares for diesel trucks have been drawing closer in each of the last six years. Ford’s dominance, which peaked at 75 percent in 1987, slipped to 40 percent at the end of 1993.
Ford owned the market for most of the ’80s. General Motors had developed a lousy reputation for diesel engines, when it tried to convert gasoline engines into diesels for passenger cars in the late ’70s. And Chrysler became a player in the diesel market in 1987, when it began buying diesel engines from Cummins.
With the much-revered Cummins engine, Dodge quickly began taking diesel market share from Ford. Its penetration peaked at 36 percent in 1991, just as GM came back with a new turbocharged, 6.5-liter, diesel engine.
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GM’s Chevrolet and GMC Truck divisions further eroded Ford’s share and took some from Chrysler. By the end of last year, the combined Chevy and GMC share stood at 30 percent, compared with 26 percent for Dodge.
Now Ford is out with the latest advancement, a massive 7.3-liter turbocharged, direct-injection diesel from Navistar that gives it a competitive edge in horsepower, hauling and fuel economy.
“When you’re talking about appearance or you’re talking about engines that are close in horsepower, torque or function, loyalty tends to win out,” said Steve Lyons, general marketing manager of the Ford Division. “But when one company offers a pretty definite advantage, that’s where at least you’ll get some measure of changeover.”
But diesels aren’t for everyone.
They idle more roughly than gasoline engines and accelerate more slowly, creating more noise and smoke. They’re also more difficult to start in cold weather.
But mechanically, diesels are somewhat simpler than the typical gasoline engine.
Gas engines depend on spark plugs and a complicated electrical system to ignite the fuel-air mixture, while in diesels, the fuel-air mix is compressed enough to spontaneously ignite.
So, diesel engines last longer and get better mileage than comparable gasoline engines.
It’s not uncommon for a diesel engine to run 300,000 or even 400,000 miles with less maintenance than gasoline engines.
All three automakers have sought to improve typical, sluggish diesel acceleration by turbocharging their engines.
When deciding whether to pay an average of $3,500 more for a diesel, truck buyers calculate how hard and long they expect to run their trucks.
If they have to haul heavy loads or plan to drive 100,000 miles a year, a diesel makes sense.
That’s also why diesels are offered only in the biggest pickup trucks, typically ones that can haul a three-quarters of a ton or 1-ton payload.
Ford’s new Power Stroke diesel is considered the baddest dude on a very tough block.
Built by Navistar, the Chicago-based truck company, it’s a version of the heavy-duty diesels Navistar puts in its big tractor-trailer rigs.
The new engine directly injects fuel into the cylinders to boost power to 210 from 190 and has a completely electronic control system.
That improves fuel economy and makes it much easier to start, though it’s still a throaty-sounding experience.
Electronic controls also make for a smoother ride in those first few miles, when the diesel’s superhot compression chamber is warming up.
Using computers to make gasoline engines run better is so common, Lyons said, that “we don’t even think about it anymore in terms of our cars. But it wasn’t that many years ago that we had all sorts of mechanical carburetors and fuel-injection systems on our passenger cars.”
Now diesels are catching up.
The new Dodge Ram pickup that went on sale last fall is the most striking pickup on the road, with its bulging fenders, rounded snout and chrome, beer-keg grille.
But when Chrysler started offering Cummins’ 5.9-liter, diesel as an option in 1987, the engine went into Dodge’s old D-trucks-a design that’s been on the road for 15 years.
Despite the truck’s shortcoming, truck buyers loved the new diesel, quickly making it the most popular engine Dodge offered and creating a surge in sales.
“To a great extent, it helped the D-truck survive those years while we waited for the new Ram,” said Bart McLellan, chief of Dodge Truck Product Plans.
Indeed, more than half of the 80,000 or so full-size pickups sold by Chrysler in each of the last few years had the Cummins diesel.
But Dodge’s share of the diesel market peaked at 36 percent in 1991. It fell to 26 percent last year as buyers, teased for months about the long-overdue replacement, waited to buy.
Now, with the critical acclaim for the styling of the Ram and customers’ continuing love affair with the Cummins power plant, Dodge figures to regain some diesel market share.
Karl Klement, who owns Dodge and Ford dealerships in Decatur, Texas, says the Dodge used to be in demand because it was the most powerful. Now the Ram is selling because it looks good.
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“This new Ford will outrun them hands down,” Klement said.
GM’s gain during Chrysler’s slippage is partly because of the diesel engines GM developed and guaranteed for 100,000 miles, the same as Dodge and Ford.
There probably wouldn’t be so many great new diesels if tough, new environmental regulations weren’t pushing carmakers to make those trucks run cleaner and quieter.
“Diesel is moving in the direction that passenger cars did 12 to 15 years ago as they started going through more and more emissions requirements,” said Ed Hermann, manager of Ford’s light truck diesel program.
Next year, for instance, California will require more reductions in nitrogen oxide emissions and electronics to monitor and control all emissions will be required later this decade.
The big challenge, and one that can’t be met, is further cuts in nitrogen oxide emissions early in the next century.
What will that mean for diesel pickups?
“The opinion that I have is we’ll go through two phases,” Hermann said. “One is marked improvements to go along with the added costs of the engines. Then we’ll get to the point where the regulations are so strict we’ll ask the question whether it’s worth it.”