Is the high price of gas really the issue?

The other day I was hammering away on my computer, checking my e-mail and tending to my Internet business when I came across an article on the ten most fuel efficient cars. I read it, since that’s what my mileageman1.com business involves, and came away with some questions.

If the price of gas is gouging into everyone’s pocket book like it appears to be, and people are suffering financially because of it, why would they consider buying a new car that will cost them hundreds of dollars per month? Many of those same people have vehicles that are paid for, or close to being paid for, and the vehicle is completely serviceable.

If you own a car that gets 20 MPG, trade it for a car that gets 25 MPG, drive 10,000 miles per year and gas costs $4.00 per gallon, you will use 100 gallons less per year and save $400.00. If you keep the car for 3 years, you will save $1200.00. If gas goes above $4.00 per gallon, and there doesn’t appear to be any guarantees that it won’t, you could save even more. On the other hand, if your car is paid for and the payments on a new car are $300.00 per month, in four months time you will have eaten up the three years of savings you would have realized. Even if you need a new set of tires, throw in an extra $300.00, and a major tune-up, another $200.00, you still come out a little over six months in the hole at the end of the first year. I haven’t seen any warranties that cover tire wear and many of the other costs of driving a car. In that case we have to ask ourselves, “What is the real issue?” Is it really money or something else?

Do we have options? Sure we do, and one is to drive like we really want to get better fuel economy and save money. Check your tires for proper inflation, change the oil and do tune ups when they need to be done. Consolidate and eliminate: a car that gets 20 MPG can get as little as 5 MPG on short trips of four miles or less. Knowing some information about how things work is also a good idea.

Cars have had oxygen sensors on them since the early 80’s, but few people even know what or where they are. Oxygen sensors, more commonly known as O2 sensors, send information to the computer telling it whether the engine is running too rich or too lean. The sensor is a zirconia ceramic probe that usually has a thin coating of platinum. The sensor screws into the exhaust manifold or directly in front of the catalytic convertor. Many new cars have a sensor in of front and behind the converter; the rear one tells if the converter is doing its job. Early O2 sensors had one wire, second generation ones had two and the later ones have four wires.

The O2 sensor in front of the converter generates its own voltage, through the interaction of the exhaust heat and the metal coated probe, and the voltage is sent to the computer. The higher the exhaust heat, the higher voltage. The computer processes this information along with input from other sensors, one of which measures outside air temperature. The difference between the outside air temperature and the exhaust is calculated, using voltage and resistance values, by the computer and the fuel injection rate is adjusted. If the O2 sensor is getting sluggish or it fails, the computer gets faulty information, the air/fuel ratio fluctuates, the computer ends up guessing and goes to the default settings which causes fuel economy and driveability to become erratic.

The sensor can be checked with special equipment or with a propane torch and a voltmeter, if you know what you’re doing. If the person testing the sensor uses an ohmmeter they will ruin the sensor. Ohmmeters send an electrical charge through the item being tested and any electrical input will ruin the sensor, including shorting it out. If you don’t know what you’re doing, don’t do it.

Some of the symptoms of a bad O2 sensor are fluctuating fuel economy. One you get 30 MPG and then it drops drastically, later it’s not so bad and then goes down again. There can be other problems, but a roller coaster ride involving fuel economy can indicate a faulty O2 sensor. Poor drivability, jerky acceleration or loss of power can all be O2 sensor related.

Nothing will cure defective sensors, engines that burn oil or trouble codes that haven’t been remedied. If you have computer and sensor problems, they need to be remedied before spending money on items to increase fuel economy. Some work, many don’t and some are pure “pie in the sky.”