NAPA, Calif. -- Freightliner plans to increase the operating range of some natural-gas-fueled trucks out to 800 miles. Beginning in 2014, the NG Cascadia 113 will come with an optional aerodynamic package and a 48-inch sleeper option, company officials told reporters at a press event last week.

It has been just five years since the Cummins Westport ISL G made natural gas a viable fueling option for a handful of industry segments, such as port-based container trucks, refuse trucks, and some vocational and construction applications. The much-anticipated 12-liter natural gas engine from Cummins Westport, the ISX12 G, came along in 2012, opening up a vast number of new markets for natural gas trucks.

"That engine was been touted for two or three years prior to its launch," said Freightliner Natural Gas Sales Manager Bob Carrick. "Never before has the cart been so far ahead of the horse than was the case with the ISX12 G."

Freightliner has about 100 trucks in service now equipped with the ISX12 G and Allison 4000 automatic transmissions. Carrick said they have been on the road for a little more than a year, and they have been performing well. But as the configuration proves itself, and as fueling infrastructure improves, more customers are seeing opportunities. That has led to some ambitious development plans at Freightliner.

Starting this month, the Cascadia 113 will be offered with a 400-horsepower/1,450-pounds-foot ISX12 G.

"We'll start building trucks with the 400-horsewpoer engines on August 15,"  Carrick said. "We'll also have a manual transmission option available, and we already have quite a few orders for that combination."

Eaton announced on August 2 that its lineup of manual transmissions will be available as an option on Freightliner chassis equipped with Cummins Westport ISX-12 G engines beginning in September.

Freightliner -- through its CNG fuel tank supplier, Agility Fuel Systems -- is expanding its storage tank options to include both saddle-mount and back-of-cab CNG tanks with a total of up to 190 diesel-gallon-equivalent fuel storage. The saddle tanks can be installed on the right or left side or both. Each tank, in either 40 or 45 DGE, weighs about 1,700 pounds.

The back-of-cab tank system can be fitted with up to four 25 DGE tanks. It can be used in combination with one or two saddle-mount tanks. The cabinet and the four-tank installation weigh about 2,600 pounds.

LNG tanks will be available in 119- and 150-gallon capacity (55 and 70 DGE respectively). Two 150-gallon LNG tanks will give you 140 DGE at a weight of 2,130 pounds.

"The tanks do add weight, but when you compare them against the weight of our current diesel emissions hardware plus 150 gallons of diesel fuel, the differential is only about 500 pounds," Carrick noted, adding, "LNG is the tank of choice for customers looking for the lowest weight offering as well as the ability to fuel very quickly."

Fuel tank range

Customers are also looking for longer range from a natural gas fill up. The potential range varies with the type of fuel, the type of fill and obviously the fuel efficiency of the truck and engine. The standard rule of thumb for calculating range is to use 80% of the tanks DGE capacity multiplied by 5.5 mpg. Two 70 gallon DGE tanks at 5.5 mpg would run about 600 miles.

The 40 DGE saddle tank combined with 75 DGE in the cabinet give the truck an operating rage of up to 650 miles.

The 40 DGE saddle tank combined with 75 DGE in the cabinet give the truck an operating rage of up to 650 miles.

With improving fuel economy and growth in tank capacities, and depending on the fill technique, it's now possible to get up to 90% useable capacity from a tank. With dual 70-gallon DGE tanks at 90% useable fill at 6 or even 6.5 mpg, range is stretching out to 700 or 750 miles.

Mike DelBovo, president of Saddle Creek Transportation -- presently Freightliner's largest NG customer with more than 100 NG trucks and over 12 million miles of field experience -- is getting 600 miles per fill on his M2 112 CNG trucks at 6 mpg. He expects his new Cascadia 113 CNG trucks with 400-horsepower/1,450-pounds-foot ISX12 G engines and different gear ratios to get up to 6.5 mpg and run at least 700 miles per fill. With the advanced aero package he'll soon get from Freightliner, he's looking for even more -- perhaps as much as 800 miles per fill.

"There's a difference between the range the supplier will tell you and what we get in reality, after you factor in traffic, idling, etc.," DelBovo said. "With my third-generation M2s I can comfortably run 625 miles. With the new HOS rules, that's about the limit to the workday anyway. With the time fill (a slow overnight filling process) I can get 90% useable fuel capacity."

Aerodynamic treatment

The growing acceptance of natural-gas powered trucks is fueling demand for a wider range of service applications, and that has pushed Freightliner to offer trucks suitable to a broader customer base, including more over-the-road fleets.

Carrick said during the first five years of the development of modern natural gas engines, customers really didn't care much about aerodynamics or other efficiencies. He says they were just very happy just to get a factory-built natural gas truck and not a conversion.

"Today, customers are demanding enhancements like better aerodynamics, greater range and lighter trucks," he said. "Beginning mid-year 2014, Freightliner will offer an Evolution Aero Package for the Cascadia 113 day cab that will be very similar to what's on the Cascadia Evolution today. Our engineers believe this will contribute 3% improvement in fuel economy."

Freightliner and Agility have been able to reduce the width of the tank cabinet and make room for the aerodynamic cab side extenders. The new tanks are shorter in length, but greater in circumference (80" x 26"), so the three-tank, 75-DGE cabinet now fits behind the cab with room for the side fairings. The four-tank cabinet is too tall for the standard roof fairing. Carrick said Freightliner is working on a solution for that.

The package includes a roof fairing and cab side extenders and it will be available on all CNG or LNG Cascadia 113 models except those with the 100-DGE back-of-cab fuel tank cabinet.

Trucks equipped with CNG or LNG saddle tanks will not get chassis fairings, but the fairings will be offered to fill that gap in trucks without saddle tanks.

Also available starting mid-year 2014 will be a 48-inch sleeper for the Cascadia 113. It will include full fairing packages designed to work with natural gas vehicles with any tank configuration.

If you're doing the math, you'll be thinking that the tanks and cabinets will add length and weight to the chassis that will compromise payload. That's true, but Freightliner, for one, is actively lobbying for some exemptions for this arguably greener alternative fuel.

"We're actively working with Washington lawmakers to get weight and length waivers for natural gas vehicles," Carrick said. "We're asking for 2 feet in length for straight trucks using natural gas, and 2,000 pounds for tractor-trailer combinations using either CNG or LNG. There is a precedent there with the APUs weight increases we got a few years ago, so most people we talk to think this will pass sooner rather than later."

Customer demo program

Freightliner is currently running a customer demo program with five Cascadia 113 CNG tractors equipped with the 400-horspower/1,450-pounds-foot ISX12 G engines. They are on an 18-month lease from Penske Truck Leasing, and are permitted and licensed so customers can haul their own loads in real-world operations comparing the performance of the CNG truck against their existing diesel fleet.

There's one truck available for each of Freightliner's U.S. sales regions and one truck for Canada. Customers can have the truck for a week at a time, Carrick says, not just for a trip around the block.

"One of our goals is to get the trucks into the hands of customers who may be leery about the performance of the 12-liter engine," Carrick said. "The other thing we're trying to do is get the dealer organization more involved in the natural gas product, especially in areas where a lack of fuel supply might have been a problem in the past."

Long-term strategy

Carrick said the next priority is to get assembly-line installation of the fuel tanks so the truck can be built and driven off the line at the factory without shipping the truck to an intermediary for installation. That secondary transportation, he says, can add several thousand dollars in freight costs to the assembled truck because they have to be decked and hauled to the installation site.

"We are the only OEM I'm aware of that's doing the tank installations at the plant, driving the truck away and warranting that package," Carrick said. "We'll very soon be adding the Cascadia 113 to that capability."

Freightliner's 114SD set-back proof-of-concept truck, equipped with an ISX12 G, set up for a roll-off operation

Freightliner's 114SD set-back proof-of-concept truck, equipped with an ISX12 G, set up for a roll-off operation

Going forward, Freightliner is looking at the standard 114SD and the set-back axle version as a vocational platform for the ISX12 G engine in higher horsepower applications. Freightliner had a 114SD set-back-axle proof-of-concept truck on display in Napa set up with a roll-off body. The 114SD is currently available with the 9-liter Cummins Westport ISL G engine in refuse, concrete mixer and other applications.

Looking out a couple of years, Carrick said 7-liter and 15-liter products are under consideration.

"It would be wonderful to have an engine that would fit every one of our platforms, including Thomas Built buses," he said. "And to really get this product going, we'll need a 500-horsepower/1,750 pounds-foot 15-liter engine."

At the Mid-America Trucking Show in March, Ed Pence, Cummins vice president and general manager of Heavy-Duty Engine Business, announced that the company had already begun development of a 15-liter heavy-duty, spark-ignited natural gas engine based on the ISX15 platform. At MATS, Pence said the ISX15 G is expected to be in limited production by 2014.

Join Equipment Editor Jim Park on a walk-around of the CNG-powered Cascadia 113 with the 400-horsepower/1,450-pounds-foot ISX12G:

About the author
Jim Park

Jim Park

Equipment Editor

A truck driver and owner-operator for 20 years before becoming a trucking journalist, Jim Park maintains his commercial driver’s license and brings a real-world perspective to Test Drives, as well as to features about equipment spec’ing and trends, maintenance and drivers. His On the Spot videos bring a new dimension to his trucking reporting. And he's the primary host of the HDT Talks Trucking videocast/podcast.

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