Friday, June 24, 2016

Tire Strategies to Save Fuel

Question of the Month: What vehicle tire strategies and technologies are available to save fuel?

Answer: It’s easy to understand why tires are essential to a vehicle, but tires also play an important role in your vehicle’s fuel economy. Tires affect resistance on the road and, therefore, how hard the engine needs to work to move the vehicle. By maintaining proper tire inflation or investing in low rolling resistance or super-single tires, you can improve your vehicle’s fuel economy. Whether you drive a light-duty vehicle (LDV) or heavy-duty vehicle (HDV), there is a tire strategy or technology to help you increase your miles per gallon (mpg).

Proper Tire Inflation

Properly inflated tires increase fuel economy, last longer, and are safer. Oak Ridge National Laboratory estimates that you can improve your gas mileage by up to 3.3% by keeping your tires inflated to the proper pressure. In fact, under-inflated tires can lower gas mileage by up to 0.3% for every one pound per square inch drop in pressure in all four tires. It is especially important to keep an eye on tire pressure in cold weather because when the air becomes cold, the tire pressure decreases.

You can find the proper tire pressure for your vehicle on a sticker located on the driver’s side doorjamb or in the owner’s manual. Also, check to see if your vehicle is equipped with a tire pressure monitoring system (TPMS), which will illuminate a dashboard light when the tire inflation, in one, multiple, or all tires reaches a certain pressure threshold. Fleet managers, in particular, may consider using telematics with a TPMS to assist their drivers with maintenance. Even if a vehicle has a TPMS, however, it is still good practice to manually check your vehicle’s tire pressure in order to ensure all of your tires are properly inflated.

Low Rolling Resistance Tires

Rolling resistance is the energy lost from drag and friction of a tire as it rolls over a surface. This phenomenon is complex, and nearly all operating conditions can affect how much energy is lost. For conventional and hybrid electric passenger vehicles, it is estimated that about 3%-11% of their fuel is used just to overcome tire rolling resistance, whereas all-electric passenger vehicles can use around 22%-25% of their fuel for this purpose. For heavy trucks, this fuel consumption can be around 15%-30%.

Installing low rolling resistance tires can improve vehicle fuel economy by about 3% for LDVs and more than 10% for HDVs. In LDVs, a 10% decrease in rolling resistance can increase fuel efficiency by 1%-2%. Investing in low rolling resistance tires makes economic sense, as the fuel savings from the use of these tires over the life of the vehicle can pay for the additional cost of the fuel-efficient tires. Most new passenger vehicles are equipped with low rolling resistance tires, but make sure you keep rolling resistance in mind when shopping for replacement tires.

Super-Single Tires

Reducing vehicle drag can provide significant fuel economy improvements. One way HDVs can reduce drag is by replacing traditional dual tires with one super-single tire—also called a wide-base or single-wide. In Class-8 heavy-duty vehicles (see the April Question of the Month for a definition), this can save fuel by reducing vehicle weight and rolling resistance. A super-single tire is not as wide as two tires, so there is a slight aerodynamic benefit as well, further improving vehicle efficiency.

More Information

For more information, see the following pages:


Clean Cities Technical Response Service Team
technicalresponse@icfi.com
800-254-6735

Tuesday, June 14, 2016

Has OPEC lost its grip on oil prices?

In an article on USA Today, Hossein Askari, Iran professor of business and international affairs at George Washington University, says "OPEC is just powerless. They cannot agree to anything, both for political reasons and economic realities."
"I think we're in a newer paradigm for the oil market," said Rob Haworth, investment strategist and commodities expert at U.S. Bank Wealth Management. OPEC "can't afford to cut production in a meaningful way, so we are back to the market and the fundamentals of supply and demand and cost of production being the driver of price."

Wednesday, June 1, 2016

Next Generation Heavy-Duty Natural Gas Engines Fueled by Renewable Natural Gas

This White Paper explores the need—and leading approaches—to immediately start deploying zero-emission and near-zero-emission heavy-duty vehicle technologies on a wide-scale basis in the United States.

During low oil prices, fleets with own CNG still saved money

Researcher Jon Gabrielsen says that "In the United States, with oil around $40/barrel of crude, just one alternative fuel remained cost-competitive, the analysis finds: compressed natural gas, or CNG." "I had to concede that despite the challenges to equip for CNG and the costs to upfit the vehicle, the savings are even larger, making it the lowest break-even proposition against diesel."

You can find his report here.

"Any time that one can fuel a commercial vehicle with CNG for at least fifty cents per DGE less than with diesel fuel then one will have at least a 3-year or shorter payback by having equipped for CNG instead of diesel."