On The Road FAQs

Please email your questions about household or commercial energy use and sustainable transportation to comments@bouldercolorado.gov.

Q: What is the city of Boulder doing internally to reduce greenhouse gas emissions from transportation?

A: The city of Boulder currently uses E85, B20, propane and CNG (Compressed Natural Gas) in its vehicle fleet and plans to expand use of these fuels in the future. These alternative fuel choices have already allowed the city to reduce its internal transportation greenhouse gas emissions to a level below the 2012 Kyoto goal. The city also purchases hybrid vehicles.

Q: I have read that fueling a car with ethanol instead of regular gasoline emits fewer CO2 emissions. Which cars can use it and where can I get it in the Denver Metro area?

A: Ethanol fuel is a blend of plant-derived alcohol and petroleum gasoline. "E85" is a common blend containing 85 percent ethanol and 15 percent gasoline. Only "flex-fuel" vehicles can run on E85. You can buy E85 in Longmont, Arvada, Thornton, Lakewood, and Denver, and in fall 2007 we should see it in Boulder.

Q: What's the skinny on corn ethanol as fuel and how effective is it really in reducing net carbon emissions?

A: The nation doesn't produce enough corn to meet the nation's gasoline needs through corn ethanol alone. That said, corn ethanol is still a highly effective "stepping stone" to what experts expect will be a much better environmental benefactor---cellulosic ethanol, which is derived from other plant materials like switchgrass. Contrary to a commonly held misperception, it does not require more energy to make corn ethanol than the amount released when it burns, according to experts at the National Renewable Energy Lab (NREL), which maintains that corn ethanol provides 40%-60% more energy than is required during its manufacture. Tailpipe emissions from E85 are 85% lower than from petroleum gasoline.

Q: I have a 2004 diesel vehicle and I just found out I can buy biodiesel fuel in Boulder. Do I have to do anything special to prepare my car for biodiesel?

A: Biodiesel fuel is a blend of plant-derived oil and petroleum diesel. B20 is a common blend that is 20 percent plant oil and 80 percent diesel. All '1993 and newer' diesel cars and trucks can run on biodiesel or petroleum diesel. Biodiesel is cleaner than petroleum diesel and better for your engine as it tends to clean your tank, hoses and fuel pump. It's a good idea to follow regular maintenance including replacing your fuel filter after your first month of using biodiesel. You can purchase biodiesel at three gas stations in Boulder, and at four stations within 23 miles of Boulder.

Q: What are some benefits in buying a hybrid vehicle?

A: Sales of new hybrid cards were up 49% nationwide in the first seven months of 2007 (52% in the Western region), according to Associated Press, which attributes the increase to 'high gas prices and environmental concerns'. There are federal tax credits for most hybrid vehicles, and the Colorado state tax credit is similar to the federal credit. Popular models include the Toyota Prius and the hybrid version of the Toyota Camry.

Q: Is there an easy way to know how much carbon dioxide (CO2) I produce when I drive?

A: According to the EPA, one gallon of gas produces 19.4 pounds of CO2 emissions and one gallon of diesel produces 22.2 pounds of CO2. So in order to determine how much CO2 your car emits when you drive, multiply the number of gallons of gas you use by 19.4. If you are using diesel multiply by 22.2. (Example: 2 gallons of gasoline per day = 38 pounds of CO2 per day). That equals about one-third ton of CO2 per month, or about 4 tons per year. The average total footprint (household energy use + water + garbage + transportation) of the Boulder ClimateSmart calculator is 14 tons.

Q: Is there a carpool website for the Front Range?

A: To find local carpool services, contact Ride Arrangers or visit www.erideshare.com. If you are looking to carpool to the ski slopes try www.skicarpool.com. Reduce your company's CO2 emissions by asking your employer to enroll in www.ridespring.com.

Q: I often drive with the windows down because I believe less gas is used when the AC is off. Is this true? By driving with the windows open am I creating more drag and thus using more gas?

A: Running your air conditioner does cause your vehicle to consume more fuel, but driving with your windows rolled down can be even worse due to the increase of drag on the vehicle. If you are driving slowly, such as around town in city traffic, then you are better off leaving your windows open. For highway driving, roll up the windows and turn the air conditioning on.

Q: What are the differences between various transportation technologies?

A: Hybrid electric vehicles are powered using an internal combustion engine, (like you would find in your conventional vehicle) and an electric motor. To increase efficiency, a rechargeable energy storage system is used. Hydrogen vehicles are powered using fuel cells, which react hydrogen with oxygen to power an electric motor and produce water and electricity. The tailpipe emission out of this vehicle is only water, unlike a hybrid electric vehicle, but making hydrogen can produce more emissions than a conventional internal combustion engine. Plug-in hybrid electric vehicles are powered by batteries that are charged when plugged into an electric power source. If this power comes from renewable energy sources then the plug-in hybrid electric vehicle has no greenhouse gas emissions. The bicycle does not need a fuel source, produces no greenhouse gases, and is still the most efficient form of transportation available.

Q: What is the energy efficiency of a gasoline engine versus an electric motor? Which actually produces the most CO2?

A: Electric motors are more efficient than gasoline engines. An internal combustion engine loses 36% of its energy as heat, 38% as exhaust, and about 6% to friction. Electric motors on the other hand can have an energy efficiency of 90%. The gasoline engine also produces more CO2 than an electric motor does.

Q: Can you talk about ways to do both continental and international travel in a less expensive (as regards carbon emissions) mode than jet travel?

A: The best way to reduce your jet travel carbon emissions is to travel less.

Q: What makes up my transportation carbon footprint?

A: Your transportation footprint is the sum of all the travel you do with a car, motorcycle, bus, airplane, etc. The exhaust from burning fuel includes carbon dioxide (CO2, a greenhouse gas). The average Boulder resident's annual transportation footprint is 7.2 tons of CO2, assuming 9,300 miles driven annually and three, 3-hour roundtrip flights. See how high (or low) your transportation footprint is by entering your actual usage data in our ClimateSmart carbon calculator at www.beClimateSmart.com/knowYourScore.

Q: Like everyone else these days, I'm in need of tips to drive less and save money at the pumps. What are your suggestions?

A: Track your fuel economy and gallons of gas used. You might be surprised to see how many miles you drive weekly or monthly. Think about miles or trips that you might be able to cut. Are you eligible for an Eco Pass through work or your neighborhood? Ask your neighborhood organization, employer or GO Boulder (GOBoulder.net - see Bus Passes). If you do have it you are nine times more likely to ride the bus. Here are more things that will make a difference to your wallet and the climate:

Q: I'm trying to decide whether to sell my car which is not very fuel-efficient - what things should I consider?

  1. Know your car's actual fuel economy (MPG). Here's how: Zero your odometer when you fill up. At the next fill-up, record the number of miles you drove and the number of gallons used. Divide the miles by the gallons to calculate your miles-per-gallon.
  2. Estimate your annual mileage (commute plus weekend and vacation miles)
  3. Using $4/gallon as a baseline, figure out how much you'll spend on gas in a year. Compare that cost to what you'd pay driving a vehicle that gets 35 mpg and one that gets 50 mpg, then weigh the investment you might make in trading your current car for a more fuel-efficient one. The price of gas isn't likely to go down any time soon.
  4. To compare fuel efficiency of vehicles visit www.greenercars.org/highlights.htm

Q: Are there any events or happenings in Boulder that could motivate me to ride my bike more?

Yes - June is Walk or Bike to Work Month! There are all kinds of events this month promoting the benefits of riding or walking rather than driving. Check out www.communitycycles.org for information on all the events. And remember that June 25th is Walk or Bike to Work Day with breakfast stations all over town to support the bike and walk commuters.

Q: How much of the city of Boulder's greenhouse gas emissions are derived from transportation?

A: Transportation amounts to about 22% of the community's total greenhouse gas emission inventory. This percentage includes residential and commercial travel only within city limits, and does include commuter miles coming and going from Boulder. There are many ways to reduce transportation carbon dioxide emissions and dramatically lower your carbon footprint. Visit the ClimateSmart On the Road section of the city of Boulder's www.beClimateSmart.com website for more details.

Q: Is there an easy way to know how much carbon dioxide (CO2) I produce when I drive?

A: If you know your car's mile per gallon (MPG), use a calculator to do the math.
Pounds CO2 = miles driven * 19.4 pounds CO2 per gallon gas / MPG

You can also determine the gas cost with a similar equation: Gas cost of driving = miles driven * $4 per gallon gas / mpg

Example 1: 100 miles * $4 per gallon / 19 MPG = $21.05
Example 2: 100 miles * $4 per gallon / 35 MPG = $11.24

To find your MPG, zero your trip odometer when you fill up. Then when the tank is low, fill up again and divide the miles you drove by how many gallons it takes to fill the tank.

Q: Much of my job involves answering emails, balancing spreadsheets, and editing company policies. With my laptop and high speed connection, I could definitely work from home at least a few days a month. How do I convince my employer that this is a good idea? My commute is 20 to 40 minutes, depending on traffic, and I'm definitely feeling the sting of current gas prices.

A: The RideArrangers program through the Denver Regional Council of Governments facilitates telework programs, carpool matching, vanpools, and schoolpools. They have good information on the business case for telework programs. In Boulder, ClimateSmart on the Road and GO Boulder help businesses develop employee commute trip reduction programs.

Q: I often drive with the windows down because I've been told less gas is used when the AC is off. Is this true?

A: Running your air conditioner does cause your vehicle to consume more fuel, but driving with your windows rolled down at high speed can be less fuel efficient due to the increased drag on your vehicle. If you are driving around town in city traffic, then you are better off leaving your windows open. For highway driving, roll up the windows and turn the air conditioning on low.

Q: I'd like to get rid of my car to avoid high gas and insurance prices. In summer it's easy to get around by bike and by walking, but I'm hesitant to give up my car because in the winter it's not really realistic for me to get everywhere I need to go with a bike, and sometimes even the bus.

A: If you're in Boulder there is a local option called Boulder CarShare, a non profit organization that rents cars by the hour. You can lose the headaches of owning a car but still have access to one when you need it. The cars are parked throughout the city for easy pickup and return, you can check vehicle availability online with a newly updated reservation system. It is membership-based with a small annual fee, and an affordable per mile charge.