The Rise Of Diesel Performance

Few would have thought that, after so many years as a workhorse, the diesel engine would lead the next wave in performance.

This past March marked the 150th birthday of Rudolph Diesel, who invented the engine that bears his name. He unveiled his new device at the 1900 Paris World’s Fair, initially demonstrating that it could run on peanut oil. Unfortunately for Rudolph’s legacy, in North America diesel engines came to mean smoke and soot for many, especially those who prattled about in early ’80s Jettas.

Those impressions couldn’t be further from the truth. In terms of today’s light truck performance aftermarket, the dirty old diesel just might be the new industry darling.

“This business is all about fads; what’s the new thing and what’s cool, and right now, diesel is it,” says Mike DeFord, marketing manager for Bullydog Performance. “A few years ago, the cool thing was to get 400 hp out of a four-cylinder import, and the diesel truck market has evolved in much the same way; except in this market, you need to be generating 1,100 hp to be at the top.”

It is that amazing horsepower potential that may attract the tuners. “I think it’s a growing marketplace due to horsepower, emissions, and the fuel mileage benefits you can realize these days with diesel technology,” says Kevin Dundas at Karbelt. “It’s a very economical way of producing power. When you add a programmer into the mix of a standard gasoline- powered vehicle, you’re often looking at a horsepower increase of 3-4%. But with a diesel engine program, you can easily increase your horsepower by 20% or more. It provides great bang for the buck.”

DeFord sees the horsepower equation similarly. “We make gas and diesel products, and the difference in horsepower gain is huge,” he says. “On the gasoline side, we can give someone an additional 30 hp that would be economical and safe for them to use, whereas on the diesel side, we can give someone 150 hp by making the exact same changes. Basically, for $1,000 you can get that extra horsepower out of a diesel, and you couldn’t get the same out of a gas-powered engine for $10,000.”

As a result, the sales numbers and overall market reports for the truck performance market have been very strong, despite the reported struggles of other sectors of the aftermarket. “Our business continues to grow at a very steady pace,” says DeFord. “You hear a lot of talk around the industry these days about slowing or softening or whatever you want to call it, but we haven’t been affected by that. Now, we’re not hitting the numbers we had projected three years ago, but compared to some other market segments that are down double digits, the growth in the diesel market is still very strong.”

Also on the positive, Dundas notes that it is not only the performance tuning software that is doing well, but also some highly specialized components as well. “The diesel truck market is really expanding in terms of a lot of different applications,” he says. “It’s been strong and continues to be strong for programmers and bolt-on exhaust components, but now we’re seeing an increased demand for some heavy-duty internal diesel engine components as well, that we just didn’t see a few years ago.”

According to DeFord, the new boost in diesel popularity hasn’t just been a boon for the manufacturers; it has also been great for jobbers as well. “For our jobbers, selling the product has been really easy,” he says. “Since 2005 we’ve been offering our try-before-you-buy program, which allows jobbers to install a three-day trial download, for a customer who might be skeptical of the horsepower and fuel economy claims.”

DeFord says that some 80% of customers who take them up on the three-day trial offer return to the store to purchase the full version. Furthermore, DeFord says more recent market research demonstrates some more sustained benefits for the jobber. “What we’re seeing now, in terms of the trial offer, is that our jobbers are getting customers over the long term as well,” he says. “Say the truck owner wants new running boards or an exhaust system–we’re seeing evidence that he’s going to go to the jobber that hooked him up with that horsepower.”

Despite the hype, the picture is not entirely rosy for the diesel market, particularly if it is going to make the transition from trendy niche to mainstream. Despite the positive sales numbers, diesel engines have a chequered history in North America. They have always enjoyed good fuel economy (both in the city and on the highway), high torque delivery, and long durability compared to gasoline engines. However, higher purchase costs, excessive noise levels, heavy weight, and unfavourable exhaust emissions have detracted from their wide acceptance over the years. According to SEMA, consumer stereotypes represent the single biggest limitation to the growth potential of the diesel market. The company’s most recent survey suggests that 74% of respondents cited misconceptions such as “too loud” and “too slow” as being the top reasons why the diesel engine struggles to gain everyday driving acceptance.

What’s more, according to Frost and Sullivan, diesels will also face a significant legislative confrontation in the coming years. “A key challenge for the automotive light diesel engine industry is to survive the tightening emissions regulatory requirements with affordable products that continue to last well and deliver the expected good fuel economy,” notes Frost and Sullivan senior consultant Larry Rinek.

By 2009, U. S. automotive diesels (under EPA tier 2, bin 5) are required to have tailpipe emissions just as clean as spark-ignited gasoline engines. That amounts to almost zero emissions levels for both types of engines. That scenario requires near-heroic efforts for diesel engine designers, involving elaborate and costly aftertreatments, and potentially the use of alternative lower-temperature combustion technologies. The fundamental diesel emissions problem is its high generation of smog-forming NOx, plus a heavy dose of particulate matter (such as fine carbon soot).

“Some Tier 1 suppliers of key diesel engine systems, such as electronically controlled direct injection (DI) fuel systems– the most expensive purchased portion of diesel engines today–have much at stake in providing emissions-compliant solutions that will enable survival of these engines, and continued DI system sales worth billions of dollars per year,” explains Rinek.

The Tier 1 system suppliers are working hard to help diesel engine builders minimize engine-out emissions, with various DI techniques such as higher common-rail injection pressures and more injection events per cycle, combustion chamber/ piston bowl modifications, and exhaust gas recirculation [EGR] technology, as well as reduced tailpipe-out emissions via effective exhaust aftertreatment downstream of the engine.

The above strategies, plus alternative combustion schemes, could help the automotive diesel industry to survive and prosper in North America, at least according to the research experts.

Despite poor stereotypes and consumer impressions, Dundas insists that hearts and minds are being won over. “Improvements in technology have obviously contributed to the popularity,” he says.

“Measures taken to reduce the noise and the smell have also helped reduce the ‘rattlebox’ image. People aren’t afraid to turn the key in public anymore, so the biggest change has been in the usage of [diesel] trucks. These vehicles used to be only workhorses, but now they are much more of a dual-purpose (work and everyday driving) type of vehicle.”