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Could a dual fuel conversion be the right move for an aging fleet?


I’m a big fan of alternative fuels, so I jumped at the chance to test drive a dual-fuelled tractor. My ride was to be 2007 International 8600 model powered by an 11-litre Cummins ISM engine that had been converted to run on a 75/25% blend of diesel and CNG (compressed natural gas), respectively. It was waiting for me at the Woodstock, Ont. ONroute rest area on the 401 and I was late.

LNG (liquid natural gas) has been proclaimed to be the alternative fuel that’s going to knock diesel off its perch, but CNG has its proponents as well. I was struck by a curious juxtaposition when I pulled into the rest area truck parking lot. While giant carriers like Bison and Robert have invested millions of dollars in decked-out LNG-fuelled 386 Peterbilts, my ride was a seven-year-old Cornbinder day cab with half a million kilometres and a sagging seat that had been retrofitted in a local Kitchener garage. 

The 2007 International is a demonstration unit provided to W.S. Bell Cartage by Alternative Fuels Alternative Solutions (AFAS) in partnership with Universal Truck Rentals, and was, at the time, undergoing a five-week trial. The tractor was slotted into a dedicated auto parts run between Kitchener and Windsor, Ont., and the driver, George Lazenby, was waiting for me. The plan was for me to drive the truck into Kitchener and see how this CNG/diesel handled itself at highway speeds and under loaded conditions.

About half the trucks I drive these days are automatics, but I’m always at home with an Eaton Fuller 10-speed, and happily skipped a gear or two coming out of the service centre. The truck creaked and groaned a bit (its odometer read 468,000 kms) but its 410 Cummins’ horses got up to highway speed in no time and sailed along fine. A push-button indicator on the dash engages the CNG and four tiny LED bars indicate how full the tank is in quarterly increments. Otherwise the dash panel is exactly the same as any other 8600.

I wasn’t expecting anything dramatic and Steve Baty, director of AFAS, had told me so. “It’s going to drive exactly like any other truck,” he warned.

But the real test of this blended fuel system is the driver George Lazenby, himself. This is the kind of driver you want to hire – old school, and guys like him put “class” in a Class A licence. With a couple of million miles under his belt, he doesn’t waste much time on small talk. At 69 years of age he’s seemingly indefatigable, putting in close to 60 hours a week, and pretty well doing the work of two drivers. 

“We didn’t even tell him we were testing CNG,” according to Baty of AFAS. “We started out with him running on diesel alone. We wanted him to drive exactly the same way as he would any other truck.” 

Lazenby had given up his late model Mack sleeper cab for five weeks while piloting the demonstration model. He also had to make a stop every trip in Chatham to fill up the CNG tank, sometimes having to wait in a line-up behind Chatham city buses that also run on CNG.  

“George was skeptical (of the CNG blend) at first,” says Dallas Bell, vice-president of W.S. Bell Cartage, “but he seemed to get more comfortable and was happy to stick it out to the end.”

Cosmetically, the only visible difference from a factory 8600 is the extended CNG tank on the passenger side. The tank is 66 inches long, 23 inches in diameter but fits within the frame. The tank holds the equivalent of 80 gallons of diesel, but even so, it’s not enough CNG to make the whole 600-km journey, running out after 400 kms. Baty suggests that another tank could be added behind the cab or even on top of it. 

Baty chose the 8600 because the conversion is rather simple with most of the piping fitting neatly on the right side of the engine. But he insists a conversion can be fitted to any truck. 

“Any truck, any engine, any year,” he says. But unlike the expensive LNG Peterbilts running up and down the 401, the AFAS conversion can be done for a fraction of the cost, less than $25,000. The big difference says Baty, is that “it’s still a diesel with a dual-fuel CNG fuel management system enhancement.”

Besides the cheaper cost of running CNG, Baty also claims to have gotten better mileage by fine-tuning the engine to run on the CNG/diesel mixture, from 5.6 miles per US gallon to around 10. The truck starts and idles on diesel, while CNG is gradually added as the rpms increase and the turbo kicks in, until the optimum 75/25% ratio is achieved. Baty thinks that that ratio can also be improved eventually to a 60/40% mixture cutting fuel costs further. 

When I asked Lazenby about the performance, he was unequivocal. “No difference,” he said without blinking. And the same goes for me. The CNG blend worked as well as any Cummins-powered International I’d ever driven. After I’d backed the trailer into dock in Kitchener, Lazenby bobtailed us back to Bridgeport where W.S. Bell has its headquarters. 

Overall, the trip was relatively unremarkable and that’s good – the blended fuel conversion was indistinguishable from full-on diesel. The bottom line is savings, of course. Based on George’s trial runs, Baty estimates that it would save over $16,000 in fuel in the course of a year, and over $20,000 if it could carry enough fuel for the entire round trip. 

Bell is generally pleased with the results. 

“Ideally we’d like to try it with a newer truck,” he says. “We’ll have to sit down and confer about our next step. With the limited number of fuelling spots it would have to be the right run and the right truck.”

One option is to put in a “slow fill” fuelling station where individual trucks could be fuelled over the eight to 12 hours when they are off-duty. This can be done at any site with natural gas service. 

But like so many issues concerning new technologies, it is expensive to put in a slow fill terminal, about $12,000 per unit. 

But on paper a dual-fuel CNG conversion looks like an affordable option considering the cost of new LNG and CNG engines. 

Rather than a payback period of 3.5 years for new LNG equipment, the AFAS dual-fuel system should pay for itself in 18 to 24 months, says Baty, based on the amount of daily travel and the cost of the fuel cylinders chosen. 

“The fuel cylinders are the most expensive component of the dual fuel management system,” he adds.


Harry Rudolfs

Harry Rudolfs

Harry Rudolfs has worked as a dishwasher, apprentice mechanic, editor, trucker, foreign correspondent and taxi driver. He's written hundreds of articles for North American and European journals and newspapers, including features for the Ottawa Citizen, Toronto Life and CBC radio. With over 30 years experience in the trucking industry he's hauled cars, steel, lumber, chemicals, auto parts and general freight as well as B-trains. He holds an honours BA in creative writing and humanities, summa cum laude.
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1 Comment » for Could a dual fuel conversion be the right move for an aging fleet?
  1. Pete Vanderwyst says:

    We at ECL have been running a dual fuel system on a 2012 Series 60 500 HP Detroit for the past 5 months.
    I find the fuel improvement suggested in your article to be outrageously off at 5.6 to 10 MPG improvement. Over an year with the suggested routing as indicated above that would be an yearly savings of $30 K a year . From any of the information I have gathered the last 5 months on our test unit – I find it hard to believe the #’s to be true. Feel free to call me. 519 671 6218

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