Fixit: Driving slower burns less fuel

By KAREN YOUSO, Star Tribune

Last update: February 11, 2008 - 4:55 PM

Q A recent recommendation to reduce greenhouse gas emissions and combat global warming was to drive our cars slower. Please explain why driving slower would reduce emissions. Wouldn't it be just the opposite? If you drive more slowly, it will take longer to get where you're going and the car will be on the road longer.

A Driving slower may take you longer to get where you're going, but you will burn less fuel overall.

To travel faster, you must operate the engine at a higher RPM; this requires more fuel because the car's cylinders fire more frequently. In addition, wind resistance increases at higher speeds, and this requires more energy to overcome.

Also, cars are designed to operate most efficiently in a given RPM range, and traveling faster generally has the engine running above this range, which consumes more fuel.

To bring the physics principles a bit more into focus, try riding a bicycle 1 mile in 15 minutes and then do the same distance in 5 minutes. This will demonstrate the added energy required to arrive at your destination faster.

Renter's credit

Q Can I get a renter's refund from the state even if I don't file income tax? Do I need to apply by April 15? How does renter's credit work?

A If you don't have to file a federal or state tax return, then you don't need to file to get a property tax refund, according to the Minnesota Department of Revenue. (You do, however, need to determine your federal adjusted gross income, if any, to apply for the refund.)

The state-paid renter's refund is property tax relief for renters whose rent (and the implicit property tax there) is high relative to their incomes. Rent contributing to property tax is assumed to equal 19 percent of the rent paid.

The size of the refund depends on the household income, the number of dependents and how much property tax is considered to have been paid. The most that any renter can receive is $1,430; the average return in 2006 was $536.

Forms and instructions for renter's credit are available at www.taxes.state.mn.us/taxes/prop_refund/forms. shtml. They're also found at many libraries, or you can have a copy mailed to you by calling 651-296-4444 or 1-800-657-3676.

The deadline for applying for renter's credit is Aug. 15.

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av. S., Minneapolis, MN 55488, or call 612-673-9033, or e-mail fixit@startribune.com. Past columns are available at www.startribune.com/fixit. Sorry, Fixit cannot supply individual replies.

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