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Frequently Asked Questions
What does Natural Gas do to truck/tractor weight?
CNG - The BOC package weighs 2200lbs. full. The same amount of diesel on board a regular truck would weigh 800lbs. Therefore, there is a 1400lb. weight disadvantage to CNG. However, there is no DPF necessary on a CNG truck. This saves about 600lbs. So...there is net disadvantage of 800lbs CNG vs diesel.
On a Cascadia with 155 DGE, the truck weighs about a 2000 pounds more vs. diesel.
LNG - With LNG the add on is minimal, about 100 pounds.
How quickly can a truck be refueled?
CNG - Fill rates vary among fuel stations. Some refueling stations pump 1 gal. (DGE) per minute. Others can pump up to 20 gal. (DGE)per minute. A station is considered to be quick fill if it can pump at least 5 gal. (DGE) per minute.
LNG - Because it is a liquid, LNG fill rates are similar to diesel.
What about maintenance costs?
The spark plugs need to be changed at 45000 mile intervals. This should cost around $460 per change ($360 parts + 1 hr labor).
PM's are every 15000 miles vs 30000 on a diesel.
How many refueling stations are there around the country?
CNG - Approximately 300 truck friendly (5 gal. per minute) stations.
LNG - Approximately 30. Most LNG stations are located in Southern California. However, Pilot and TA's are installing LNG pumps with ???? stations projected by 2014.
Does a driver need a hazardous certification to drive a NG truck?
No
What horsepower and torque ratings are available?
Cummins ISL G - 250 to 320hp and 660 to 1000 lb/ft torque
Cummins ISX 12 G - 320 to 400hp and 1150 to 1450 lb/ft torque
What is the B50 life of a natural gas engine?
Cummins ISL G - The exact same as its diesel counterpart (500,000 miles). Remember, 80% of the parts of the NG engine are the same as the diesel version of the engine. The ISL G and the ISL use the same block, crankshaft, main bearing, and piston rods.
What is the difference between a dual fuel vehicle and a bifuel vehicle?
Bifuel - The vehicle will run on either natural gas or diesel/gasoline. The driver can select which type of fuel to burn and there is virtually no difference in performance.
Dual fuel - The engine uses diesel as a "pilot fuel" to begin combustion inside the cylinder. Only trace amounts of diesel are used so significant cost savings are achieved because the engine is primarily using natural gas. No spark plugs are necessary on a dual fuel engine (compression inside the chamber ignites the diesel which, in turn, ignites the natural gas). However, because diesel is being used for ignition purposes, an SCR system is required on the truck.
How does natural gas affect the residual value of a truck?
Answer from Martin Daum, President and CEO of Freightliner:
At this point, it is still harder to predict what the residual value of natural gas-powered chassis will be, Daum said. “If we could predict the cost of diesel in the next five years versus the cost of natural gas, the answer to the residual question for natural gas trucks would be much easier,” he noted. “When you ask about residuals, you are really asking two questions,” Daum said. “What is the perfect residual? And who takes the risk? The second buyer is much more conservative than the first buyer because he has fewer resources and essentially only his own experience to rely on. That makes him more price-sensitive. We see that with technology now. More basic trucks still deliver the best value in the secondary market.
“We also have no historical price points yet for natural gas vehicles and there are subsidies for the first buyer besides that don’t apply to the secondary market,” he continued. “The ROI for natural gas trucks today is based on the price differential between natural gas and diesel. If I buy a natural gas truck today, I should consider running it long enough to realize my return in the first five to seven years [rather than depending on residual value].”
What about fuel economy?
For a regional haul tractor pulling 80,000lbs, there is about a 10% degradation in fuel economy. In a single axle straight truck, there is only about a 5% degradation in fuel economy.
Is Detroit Diesel going to have a natural gas engine?
Detroit has no plans at this time to produce a natural gas engine.
When will the 12L Cummins be available?
2nd Quarter of 2013
To get a sufficient ROI on the incremental costs involved with purchasing a NG truck, what does the spread need to be between the cost of diesel and the cost of CNG or LNG?
This depends on miles driven. The more miles driven, the less the spread needs to be. As a rule of thumb, the difference in fuel prices (CNG/LNG vs. Diesel) needs to be at least $1.50 to get a satisfactory ROI without government assistance.
Will the incremental costs come down as production increases as it does with most products? (Remember when calculators were $500?)
You would think so but, actually, no...not significantly. While some of the R&D costs are incorporated into the cost of the trucks today, most of the huge price difference is not in the engine or the truck, it's in the cost of the tanks. CNG and LNG tanks and fuel systems are very expensive. Even if predictions that 10% of truck purchases will be NG by 2020, the cost difference between NG and diesel trucks may not come down over time as production increases.
The following link has answers to 16 FAQ's. These questions are specifically related to natural gas and trucking. They are video answers featuring Jim Harger, Chief Marketing Officer for Clean Energy Fuels. Click the link to view the question and answer page.
http://www.cleanenergyfuels.com/products_services/trucking_qa/index.html
