Hi Guys!,
I love your show and have been listening for the past 5 years. I own a 2002 Honda Civic LX 4 door sedan. It has 39,000 miles on it. In the past 4 years it has been used almost exclusively in the city and is driven approximately 12-15 miles a week or 48-60 miles a month no more than 45 mph. Last year it was competely limited to the city (50 miles per month) and now averages about 240 miles per tank or about 18 MPG without using the A/C or speeding. I always check the tire pressure. Also, it’s acceleration is a bit sluggish. I had the air fliter and sparkplugs replaced and have used fuel system cleaner for the past 2 months but nothing helps. What is wrong with my car? Any help will DEFINITELY be appreciated.
What mileage did you see this time last year (in the same weather), for comparison? Is the car up to date on all scheduled maintenance? Is the check-engine light on? Have you changed to a different brand or model of tires recently? Has your area gone from non-ethanol gas this time last year to E10 this year?
12-15 miles per week is the hardest life a car will ever know. That’s just a few miles per day. The engine isn’t even getting warmed up correctly, not to mention the transmission and drive train. You should be following the SEVERE SERVICE maintenance schedule with this car.
Fuel system cleaner won’t help you. Stop wasting your money.
The car probably spends most of its time idling in stopped traffic getting zero mpg, or creeping along getting 1-2 mpg. Colder weather exacerbates the problem. I don’t think you can expect a whole lot more mpg under these conditions.
Would it be possible for you to walk the short distances you need to travel, or take a bus, and save the car for longer trips?
As mcparadise - this mpg probably matches your driving conditions, especially in colder weather with a car that never fully warms up. It will be worse if you’re not following the maintenance schedule for severe conditions.
Has the mileage changed recently? If so, one thing that you could do is ask a mechanic to check your thermostat and coolant temperature sensor.
But in reality I think that you need a bicycle.
Agree; this is real “Aunt Minnie” driving (an oil company term), the absolute worst for gas mileage and engine wear. The 18 mpg sounds about right for this type of driving pattern. An old Chrysler brochure on maintenance recommended changing oil every 500 miles!! with this type of operation.
I would walk or take the bus. My retired neighbor has a 5 year old Ford Focus which has had 3 oil changes. He seldom drives it but does give it a good workout when he does.
Hi,
Thanks for the post. The car got the same mileage last year and I took notice that it got slightly better mileage during the winter than summer (I chalk that up to the gas in the gas station’s tanks being more condensed in the winter). No engine check lights, everything seems normal and I ve had the same tires for the past 4 years and I still use plain 'ol regular 87 octane fuel from the same gas station.
Hi,
Thanks for replying. The car gets about the same MPG’s in the summer (without A/C). It gets slightly better in the winter owing probably to more condensed gas at the gas stations vs. fumes in the summer. The car averaged about 30 MPG when I had to drive to the airforce base where I used to work which was about 17 miles one way and it dropped to around 18 MPG when the wife started driving it to her work at a hospital 2 miles away. I will definitely ask my mechanic about the thermostat & coolant temp sensor. I can fix an F-16 blindfolded but am clueless with Hondas, do you think the oxygen sensor may be the problem? Someone mentioned that but the car doesn’t sputter, choke or have unburnt fuel coming out of the exahust. I follow the scheduled maintenance on this pretty well (oil change every 3,000 miles etc.) but even the people at the Honda service place were stumped. P.S. I live in a rural area with no bus service and a high crime rate so I can walk or bike but not the wife.
Considering the car is started and hardly run enough to warm up before your wife reaches work your mpg isn’t too far off. Fill the car up and take a 100 mile trip, refill it and then check your mpg. I think the car is fine. Drive it on a longer trip with it warmed up and your mileage is likely to be much improved. If it is mainly a highway trip you’ll get over 30 mpg is my guess.
At 15 miles a week you are only using less than 4 gallons a month of gas. Spending money to improve you mpg isn’t returning anything on your investment since you use so little fuel.
Hi,
Thanks for the suggestion. I’ve tried this by filling up my tank and driving on I-95 (with the purpose of visiting friends) and got the exact same results (240 miles per tank) doing 70 mph or under. I’m not too worried on how much I spend on gas but rather I am worried that something serious is going wrong with this car and I would like to prevent costly repairs in the future.
This is “Car Talk’s Guide to Better Fuel Economy”: http://www.cartalk.com/content/features/fueleconomy/#header3
Some of the things which can hurt mpg are: dragging brakes; an engine which doesn’t warm because the thermostat stays open, or the radiator fans run when the engine is cold; an erroneous engine coolant (or, intake air) temperature sensor; inefficient engine combustion from poor spark, timing, etc.; an engine idle control valve metering too little air (plugged up); a dirty MAF (Mass Air Flow) Sensor; a dirty throttle plate and bore; an erroneous oxygen sensor output; a clogged pcv valve; a clogged egr valve and passages; driving speeds and techniques.
Most everything likely has been already noted, so I will only add one comment. Measuring mileage by the tank full is usually not very accurate. I recommend not bothering and only measure miles per gallon and that I would only consider accurate if you measure it several times in a row and you get similar results.
Thanks!
Agree, and you have to gas up at the same station and USE THE SAME PUMP!! Every pump shuts off at a different point. Stop at the first click in each case.
Measuring gas mileage accurately is very difficult, since your driving pattern has to be consistent as well. At least 3 tanks are needed from the same pump to get a meaningful figure.
My wife worked in a medical clinic 1 1/2 miles from home. Even by parking inside, and using a block heater she seldom got over 27 mpg with a Nissan Sentra with the 1.6 liter engine and automatic. Summer and winter gas mileage was equally bad.
I would kill for 27 MPG (or buy a motorcycle).