Q: Is there a reason people leave diesel trucks running when parked? For instance, I see work trucks stopped at job sites and they are left idling while the workers are performing their work. — S.S., Chicago
A: It seems like a waste of fuel, doesn't it? Well, it is, and some companies, including bus companies, are asking their drivers to shut off their engines. The main reason it is done is that running the engine keeps the cabin warm in the winter and cool — thanks to air conditioning — in the summer. Some trucks have a power takeoff that requires running the engine. Many states and municipalities have laws prohibiting excessive idling.
Q: We are two recently retired couples who really enjoy traveling together. One couple prefers not to drive, while the other does. The trips are normally three to five days long and range from 500 to 800 miles per trip. We normally do five or six trips a year. One couple's vehicle always gets the mileage put on it. The question is, how should gas money be split on something like this, when only one couple drives? — C.P., Woodstock, Ill.
A: The place to start is with the IRS reimbursement for using one's car for business. This year, it is 56.5 cents per mile. The figure takes into account not only gasoline, but oil, tires, insurance and wear-and-tear. Throw this number on the table and begin negotiating from there.
Q: My sister has a 2003 Ford Focus wagon with traction control. However, several times this past winter she backed out of our driveway onto our snow-covered street and her right rear wheel has locked up when she shifts into low or drive. It happens with her traction control either on or off. The car moves forward but her right rear wheel is locked and not rotating. She has to back up about 40 or 50 feet, then shift back into low or drive before the wheel unlocks and rotates. I don't know if this has anything to do with it but she parks her car in our driveway and it angles up slightly, maybe two or three degrees, and she uses her handbrake. — J.M., Chicago
A: The traction control is not the issue, as you surmised. The brakes for that wheel are probably not fully releasing when she releases the parking brake. Thanks for including that bit of information. When the wheel rotates enough, the brake no longer drags and she can proceed.
Q: Last summer my 2002 Mazda 636 (65,000 miles) was taken to a Mazda dealer to have the timing belt and a couple of drive belts changed. A short time later, when the car was given a cold startup, the motor squealed like a cat that had its tail on fire. The noise would last only for several seconds and then all would be well. After several attempts to fix the noise, including new drive belts, the noise has abated to the level of a chirping bird but still occurs for a few seconds upon cold starts. — J.W., Barrington, Ill.
A: It sounds like a misaligned belt to us. Have your tech check the alignment of all the pulleys using a straightedge. Another possibility is that the tensioner pulley for the serpentine belt is wearing out. We usually replace the tensioner whenever we replace the belt.
Q: I have a 2009 Buick LaCrosse with 57,000 miles. During a recent visit to my regular service company, I was told my brake fluid and transmission fluid were "dirty" and needed replacing. My vehicle has the driver information center, and when service is needed, it will indicate so. I have received no such indication. Are these normal servicing needs based on mileage, or is this a way to create extra repairs for the service company? — J.S., Aurora, Ill.
A: Read last week's column where we discussed the issue of "wallet flushes." Visual inspection says nothing about the fluids, so do not rely on somebody's suggestion based on it. Not all services have alerts through the driver information center, so also use your owner's manual as a guide. For more information on maintenance, including maintenance beyond the owner's manual schedule, go to the Automotive Maintenance and Repair Association website, amra.org, and click on the consumer resources link.
Q: Are there any quality differences in gas between the big-brand stations (Mobil, Shell, BP) and the grocery store or discount chains? — M.M., Arlington Heights, Ill.
A: The short answer is yes, there is a difference. All retail motor fuels must contain at least the Environmental Protection Agency minimum of detergent additives. That is good. But many of the big names contain even more. If you routinely use the cheaper gas, you may want to occasionally pour some fuel system cleaner in the tank.