Q. I recently purchased a 2007 Infiniti G35X with push-button ignition, though I was concerned that I would forget to turn off the ignition. Sure enough, I forgot to shut off the car and spent three hours in the movies while the car was running.
What damage if any, did I do to my car? At what point does excessive idling harm an engine?
Push-button ignition is great, but I’m going to leave the fob in the holder in the dash when I drive the car. If I don’t remove it when I shut off the car, I will be unable to lock the door. It will be a great reminder to always shut off the car.
M.S., Glenview
A You have done harm to nothing but the environment and your finances. The computer controls fuel delivery and the cooling system. We sure hope the movie was worth it.
Q. I’ve been bringing my 2001 Honda Civic LX to a trusted mechanic. However, I am not sure he is using the 5W-20 oil recommended by Honda. My receipt says 10W-30. When questioned, he says he uses the correct oil but hasn’t updated his computer records.
I am fairly easy on the gas and brakes, drive only a bit above the speed limit (no more than 70 m.p.h.) and have been driving more and more highway miles but am not getting the mileage I used to get. Could it be the heavier oil?
J.M., Chicago
A. Yes, it could be the oil, especially when the weather is cooler. There is some energy loss pumping the thicker oil until it warms up, plus it can create some drag, much like stirring molasses.
Q. What has to be done to a diesel motor to burn biodiesel, and do you think this is a viable alternative to petroleum and hybrids?
C.M., Chicago
A. It all depends on what you mean by “biodiesel.”
If you mean B5 (or sometimes called D5), a 5 percent blend of soybean oil, for instance, and 95 percent petroleum fuel, nothing need be done. That biodiesel is made through a chemical process called transesterification that removes the glycerin.
But if you are talking about straight veggie oil collected from restaurants, that is a different story.
Neat biodiesel will run fine in an older engine with a fuel distributor and nozzles, but not in newer, injected engines. The major problems with using used cooking oil is storage (it gets rancid and can support microbial growth and attract vermin) and you need a fuel pre-heater in cool weather to keep it flowing.
In a presentation we just heard by the U.S. Postal Service fleet administrator, they see no financial advantage to using D5.
Q. I have a 2007 Toyota 4Runner 4WD Sport model. During steady rain or snowfall, should I be in the 4WD high mode on the highway or should I just keep the vehicle in 2WD?
R.R., Wauconda
A Do not use four-wheel-drive unless you need it. Not only does your fuel economy suffer, but constant use also causes wear and tear to the system. Besides, parking may be difficult as the truck may crow hop in tight turning maneuvers.
Q. I have seen various ads for magnets that can be put on either the side or bottom of an oil filter to keep metal shavings from leaving the filter. Do you believe these products would do any good? I was wondering whether these magnets are just a gimmick because any metal shavings that manage to make it past the filter element should be very small indeed.
A.T.. Grand Blanc, Mich.
A. Don’t waste your time or money. They may trap some ferrous (iron or steel) particles, but nothing else. Spend your money on good oil filters.
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Bob Weber is an ASE-certified Master Automobile Technician, having recertified every five years since 1978. Write to him in care of Motormouth, 17717 Silcott Springs Rd., Purcellville VA 20132. Send e-mail, including name and town, to motormouth.trib@verizon.net. Answers will be supplied only through the newspaper.
