Repair Topics / Mileage

• Hybrid Car Information
• Why does my engine run rough?
• How to test a fuel injector

MORE: Mileage questions

Getting the most from your gas? - It is no secret gas prices are up and putting a big pinch on our pocket books.  Car maintenance and driving habits significantly affect fuel economy.  Here are a few tips to help you get the most for your buck.  First, check the air pressure in your car's tires.  Most vehicle tire pressure recommendations are located on a sticker in the driver's door jam or on the side wall of the tire.  While tire and car manufacturers recommend a prescribed tire pressure, it has been shown that slightly more tire pressure is optimal for achieving higher fuel economy by reducing rolling resistance.  Some hybrid cars are manufactured with tires that can hold up to 55 P.S.I. as compared with the usual 32 P.S.I. For safety and better gas mileage always keep your tires properly inflated. Next, analyze your driving habits. Do you take off quickly from a stop? Try easing into the throttle and allow the vehicle to accelerate slowly.  Observe the traffic and signals in front of you. If a stop is imminent release the gas pedal and allow the car to coast the remainder of the distance before using the brakes.  Proper maintenance of your car's engine is essential for optimum performance. If your engine is misfiring it will decrease mileage. If the engine oil and filter changes have been neglected it will cause additional friction inside the engine and hinder the performance and gas mileage.  Finally, remove all un-necessary objects from the car, added weight can decease mileage also inspect your engine service records and perform a tune up or oil change as recommended. Following these gas saving tips can increase your mileage and save you money.

Question: 1994 Honda Civic DX 1.5 liter hatchback_mileage: 133,000. I recently replaced the oxygen. Should it be getting better gas mileage?

Answer: Your replacing the oxygen sensor should make your car run more efficiently. The effect on gas mileage may be very slight.

Question: 2004 Nissan Sentra 1.8_mileage: 41,000. I just bought a low mileage Nissan Sentra. The fuel economy is terrible, not what I would expect from a V6. It sometimes hesitates to start. It warms up very fast but the interior gets unusually warm as though the catalytic converter is working overtime. The excess heat comes up through the floor. What is the likely cause and solution to this problem?

Answer: Scan computer for fault codes. You will probably find one indicating that your engine is running too rich which causes the catalytic converter to overheat. Check the fuel pressure regulator and check for faulty fuel injectors.

Question:  2003 Ford Taurus 3.0 V6_mileage: 48,000.  Several months ago our Taurus city gas mileage dropped from about 23 mpg to 16 mpg.  The highway miles are still close to 27 mpg.  I have had it at two dealers who say no codes show.  They replaced the IAC and fuel pump, with same results.  When started even in warm weather the car jumps to over 2,000 rpm and remains for up to one minute.  Seems to idle rough at about 800 rpm bouncing + or - 100 rpms.  At stop lights it wants to idle high sometimes.  Is this some type of vacuum leak?  Thanks.

Answer:    Test the fuel pressure regulator to see if it is leaking raw fuel into the engine.  If that checks out okay, your problem is probably caused by a faulty MAS (mass airflow sensor).

Repair Topics / Mileage

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