Truck Fuel Tipping Point

By Tom Berg, Truck Editor | September 27, 2012

If there is a critical mass for natural gas as a motor fuel—the point at which the automotive industry will not turn back, in spite of problems and obstacles—it might be approaching if it’s not already here. Here’s why:

  • Gas is in the ground in great abundance and is being energetically extracted;
  • The fueling infrastructure is being built, though mostly at truck stops;
  • Manufacturers are offering more engines and equipment to allow operators to utilize this cheap and clean-burning fuel; and
  • Incremental costs—the premiums paid over standard diesel- or gasoline-powered trucks—are meanwhile coming down.

Throw in intense interest in natural gas reported by truck builders, and we have a bandwagon that’s rolling and picking up speed. It seems that anybody with any sense should be on it, or chasing after it, or at least watching who’s aboard and why.

The argument for gas is compelling: We have enough reserves in the United States for 100 years and maybe 200, depending on the forecast quoted. Drilling and pumping activity is boom-like in areas of Pennsylvania, Ohio, North Dakota and Wyoming, even if the process—hydraulic fracturing, or “fracking”—remains controversial. High production has brought down prices to where power plants are switching to gas from coal, which is declining in importance.

The price for natural gas as a vehicle fuel has likewise declined, and it’s cheap compared to diesel and gasoline. How much cheaper depends on where volatile petroleum prices are. NG pump prices now are about 40 to 50 percent less than the traditional fuels. Long-term, gasoline and diesel have trended upward as reserves are more expensive to access and the world’s population in people and vehicles continues to grow, boosting demand. Economic downturns cut demand and have been responsible for drops in petroleum prices in recent years, and this will recur in the future.

But prices paid at the pump for natural gas by vehicle operators won’t rise much even if gas’s basic price doubles, says Jim Harger, chief marketing officer at Clean Energy, a company active in setting up retail NG filling stations and selling the fuel. He was reacting to a recent prediction by the president of Shell Oil that NG’s price might double in a few years. That pertains to its commodities price, which only remotely affects pump price, Harger says. If the pump price is $2, the gas itself accounts for only about 30 cents of that. The rest is the cost of transporting the gas to filling stations, storing it and pumping it into truck tanks, plus some profit and road taxes.

Petroleum, however, accounts for a large portion of the price of a gallon of diesel or gasoline, sending them up or down. Crises in the Middle East send fear into an emotion-charged market, as do reports of refinery problems. Even a minor fire in a major American refinery can drive up prices, especially on the East and West Coasts. This also happens in central states when hurricanes hit the Gulf Coast.

Vast supplies of natural gas will help keep down both its commodities and pump prices, Harger says.

“Our country is rich in natural gas,” he says. “Reserves are estimated to be 8,000 trillion cubic feet (TCF); 50 percent is deemed recoverable, and the country consumes 20 TCF per year. So we have a 200-year supply. With technology improvements, we’ll likely be able to go after the balance of 4,000 TCF that we know is in the ground today.”

Cost of clean air

Meanwhile, federal law and resulting anti-pollution regulations continue to have beneficial effects on air and public health, but are expensive for vehicle operators. Diesel engines have been laden with expensive modifications and special equipment. In the past decade, three rounds of ever-stricter emissions regulations from federal authorities have added $40,000 to the price of a new Class 8 truck, according to Volvo Trucks North America.

Detroit’s Big Three builders say a light-duty diesel costs about $7,500 to $12,000 more than a gasoline engine. Ford, the one builder offering a medium-duty gasoline engine, in its F-650, says it costs $8,400 less than the diesel option. Diesels still make sense in higher-mileage operations because they use less fuel, but on-board anti-pollution equipment is complex, costly and troublesome, according to surveys of owners. New regulations on greenhouse gases and fuel economy in 2014 and ’17 might further affect equipment prices, manufacturers say.

Over-the-road operators have been gritting their teeth and buying new tractors because their old vehicles were worn out during the Great Recession, and market forces have generally allowed them to raise rates to pay for new equipment. Likewise for local delivery fleets. But it’s harder for smaller construction people for whom the recession still exists, and who must make do with old iron. Government-funded road building and repairs are still going on, and new-home building, a major segment of construction, has begun reviving. So as construction fleets get busier, they’ll need renewing. Natural gas might be a way to modernize, proponents suggest.

Local transit buses are an in-your-face example of something that works. You can’t see or smell their exhaust, and they run fine. Yes, most of them are bought and operated with big government grants, and they are owned by public agencies whose financial concerns differ from those of commercial companies. Trash trucks are a better example of what construction trucks could be. Big trash fleets now comprise the single biggest segment for heavy-duty gas power, accounting for more than half the market for trucks with gas engines. Some of these are subsidized with grant money but some are bought simply because they save big money, says Rich Kolodziej, president of NGV America, a trade association promoting natural gas as a vehicle fuel.

Why wouldn’t any truck operator consider using cheap gas? Because diesel and gasoline are still excellent fuels. They pack a lot of energy in each gallon, and they’re totally familiar: A gallon of gasoline or diesel is among the best known items in our society. Gasoline and diesel are available almost everywhere, and everybody knows how to fill up at those pumps and how to get service for trucks with diesel and gasoline engines.

Operators of construction trucks don’t always put fuel costs at the top of their priority lists—how else does one explain lines of dump trucks waiting to load or unload with their engines idling and nibbling away at fuel? But dollars spent on diesel and gasoline have to get their attention whenever more bucks are needed to top off the tanks. If operators could spend $2 or $2.50 a gallon instead of $4, the cost of idling would be even less a concern. 

Construction trucks are ideal for natural gas, Kolodziej says. “Construction trucks return to a depot every day where they can be centrally fueled. That’s the market we’ve been focusing on for years: transit buses, trash trucks, beer trucks, construction trucks.” A fueling station in the yard might seem out of the question, but not so if there’s natural gas already plumbed into the building for space heating. A slow-fill pump to service one or two trucks might cost a few thousand dollars versus hundreds of thousands for a high-volume facility that big operators need, he suggests. Slower pumping generates less heat, so the fuel expands less and tanks can be filled more completely.

Trash trucks are a good example of what construction trucks could be. They are a different configuration, but they stop and start often, somewhat like urban construction vehicles. A few operators of concrete mixer chassis have gotten the gas message and are beginning to run them. Some of these are subsidized with grant money, but some are bought simply because they save big money. Ozinga Ready Mix in Chicago says fuel-cost savings with its gas-powered Kenworths will pay off their 30 percent upcharge in about three years, and meanwhile have resulted in curiosity and goodwill among citizens.

Much natural gas equipment available for trucks

Customer interest in natural gas has caused truck makers to offer engines and fuel systems so operators can use the cheap and plentiful fuel. There are also scores of aftermarket conversion kits available, and now the domestic Big Three producers of light-duty pickups are also in the business.

None of these options is cheap, but the low cost of gas, whether purchased in compressed or liquefied form, should pay off the products’ price premiums in a few years, suppliers say. Prices for gasoline and diesel fuel are constantly changing, and observers of the oil industry say they are likely to rise again after the current downturn that seems to be at its end, anyway. The higher the cost of conventional fuels, the better the argument for alternative fuels such as natural gas.

Upcharges for natural gas options are trending downward, according to supplier representatives who spoke at a recent industry meeting. A couple of years ago, the price for a gas engine and fuel system on a new Class 8 truck or tractor was $60,000. That is now about $40,000, the reps said. For trash collection trucks, whose owners are embracing gas fuel most enthusiastically, the per-truck premium is as low as $15,000 or $20,000 to the major refuse fleets.

These engines are available now for heavy and midrange trucks:

Westport Innovations 15-liter HD dual-fuel. Based on the Cummins ISX15 with Westport’s own components, the HD (formerly called the XG) uses diesel fuel as a pilot ignition method with natural gas as the main energy source, which aids fuel economy. But it requires exhaust aftertreatment equipment similar to that used on straight-diesel engines. The HD has ratings of 400 to 550 horsepower with torque of 1,450 to 1,850 lb.-ft. and comes with the Cummins Intebrake retarder. It can be used with manual transmissions and Eaton’s UltraShift Plus automated mechanical gearboxes. The HD is available in several Kenworth and Peterbilt models.

Cummins Westport 8.9-liter ISL-G. This spark-ignition engine is based on the midrange-size but heavy-duty ISL9. It runs on 100-percent natural gas so needs only a simple three-way oxygen catalyst in its exhaust system to meet emissions regulations. The ISL-G has five ratings, from 250 to 320 horsepower, and 730 to 1,000 lb.-ft. The mandatory Allison automatic transmission compensates for the modest output by multiplying torque at startup, and constant power flow during upshifts makes acceleration brisk. The ISL-G is available in various models from Freightliner, Kenworth, Peterbilt, Mack, Volvo and Crane Carrier Corp. Later this year, it will be available in an International TranStar daycab tractor and the new LoadStar low-cab-forward truck.

Emissions Solutions Inc. (ESI) 7.6-liter Phoenix 7.6L. ESI modifies Navistar’s DT466E and MaxxForce DT with patented parts, some of them cryogenically treated; a proprietary electronic control unit; and an electronic throttle body. The rating is 285 horsepower and 820 lb.-ft., and it’s been certified by EPA and CARB to more than meet emissions limits. The Phoenix 7.6L is available in new International WorkStar and DuraStar vehicles, and can be retrofitted to existing trucks with the base engines.

Future products include:

Cummins Westport 11.9-liter ISX12-G, a spark-ignition natural gas engine that’s based on the ISX12 diesel, due out early next year. The 12-G will have six ratings from 320 to 400 horsepower and 1,150 to 1,450 lb.-ft. Higher output (compared to the ISL-G) means the ISX-G can be used with manual transmissions and not just automatics. So far Freightliner, Kenworth, Peterbilt and Volvo say they’ll offer the 12-G in various models.

Cummins ISX15-G, also a spark-ignition engine based on the 15-liter ISX diesel, due in 2014. Like the ISL- and ISX12-G, the 15-G will use a maintenance-free three-way catalyst packaged as a muffler with no other aftertreatment needed. Like most such engines, it will burn compressed or liquefied natural gas or biomethane. Cummins has not announced ratings as yet.

Volvo 12.8-liter dual-fuel engine, based on the D13 diesel, also due out sometime in 2014. It will use liquefied natural gas as the main fuel with “trace amounts” of diesel for pilot ignition, like the Westport HD. Like other gas engines, it will have a three-way catalyst in its exhaust system, plus a down-sized DPF and urea injection to eliminate diesel-caused NOx in its exhaust.

Navistar 12.4-liter dual-fuel engine being developed with Clean Air Power, an outside specialty firm. It will be based on the MaxxForce 13 diesel and, like the upcoming Volvo and current Westport HD engines, will use a small amount of diesel fuel for pilot injection and run mainly on gas. Thus it will need only a small DPF and might or might not use urea injection. A 15-liter version might follow, Navistar executives said in announcing the 13G earlier this year.

Light-duty truck entries

Bi-fuel CNG-gasoline systems are now options on Class 2 pickups from General Motors Fleet and Commercial Operations, Chrysler’s Ram brand, and Ford Commercial Truck. The ability to use gasoline addresses “range anxiety” because although gasoline is universally available in America, CNG fueling stations are still rare: about 1,000 according to GM, and 1,500, according to Ram. If an owner can’t find a CNG station, he’ll still be able to drive, though on the more expensive fuel.

In principle, there are many similarities among the three companies’ products, though each one’s system is offered in slightly different pickup models. The systems all use gasoline V-8s with hardened exhaust valves and valve seats, separate gas injectors and fuel lines, pressurized gas tanks and conventional gasoline tanks, and electronic controls programmed to operate the systems. CNG tanks are in cabinets at the front of the pickup bed, and the gasoline tank is below the bed, as usual. All will run primarily on CNG and, when those tanks are empty, will automatically switch to gasoline. All lose some power and torque while running on natural gas, but drivers will hardly notice, the builders say.

Here are brand-specific details:

Ford-Westport System. Westport Light Duty, part of Westport Innovations that makes heavy-duty diesel-based gas engines, partners with Ford in a “WiNG” bi-fuel system for SuperDuty F-250 and F-350 pickups with most popular cab and bed styles and 2- or 4-wheel drive. WiNG, for Westport Natural Gas, comprises CNG components added to freshly built Fords with specially prepped 6.2-liter V-8s. A WiNG engine will run primarily on CNG and will start on gasoline or CNG. Westport says the CNG system’s weight is 200 pounds with tanks empty. WiNG’s list price is $9,750, with a 32-gallon gasoline tank and a 14.4-gasoline-gallon-equivalent CNG tank; a 24-GGE tank is available for another $1,200. (Ford meanwhile claims the largest offering of other natural gas- and propane-capable trucks using aftermarket conversions, including Transit Connect vans, F-150 pickups, F-250 to 550 SuperDuty pickups and cab-chassis models, and the F-650 medium-duty truck.)

GM Bi-Fuel. General Motors has also chosen one basic model for its bi-fueler: a 2500 HD Extended Cab, though it can be had with a short or long box and 2- or 4-wheel drive. The trucks are produced in GM’s Fort Wayne plant in Indiana, then go to nearby Union City, where IMPCO Automotive installs the Bosch CNG equipment, which weighs 450 pounds. The gas-prepped Vortec 6-liter V-8 starts on gasoline, then switches to CNG. The gas tank holds 17 GGEs, and the gasoline tank holds 36 gallons. The upcharge is $11,000 over a gasoline-powered Chevrolet Silverado or GMC Sierra 2500 and $2,600 more than one with a Duramax diesel.  (Aftermarket propane conversions for GM engines are also available.)

Ram factory-built system. Ram will install bi-fuel equipment in its own plant in Mexico. The upcharge over Hemi gasoline power is $11,000 and about $4,000 over the Cummins Turbo Diesel option. The bi-fuel package was engineered with the help of engineers at Fiat, Chrysler’s parent and a major supplier of natural gas vehicles and equipment to Europe and other markets. It includes a gas-prepped 5.7-liter Hemi V-8 that uses gasoline for start-up, then switches to CNG until that’s exhausted, then switches back to gasoline. The CNG tanks hold 18.2 GGEs, and the gasoline tank is 8 gallons; Canadian customers can choose a 35-gallon gasoline tank. The system is initially available only on a 4-wheel-drive 2500 Heavy Duty Crew Cab with an 8-foot-long bed. (Aftermarket propane conversions for Ram engines are also available.)

Aftermarket gas conversions

Scores of products are available for truck operators wanting to convert existing trucks from gasoline or diesel fuel to natural gas, according to NGV America. It has compiled a 29-page list of suppliers and their products, and the vehicle models and engines they’re designed to convert. Some products make complete conversions to gas; others are bi-fuel mechanisms that burn one fuel or another (like the Big Three products); and some are dual-fuel, using diesel for pilot ignition (like the Westport HD and upcoming Navistar and Volvo engines); or displacing it with gas in a process called fumigation.