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I have 2005 Oddy 158k miles. I drive 500-700 miles a night 5 times a week (same place, same route). I was getting 26-29 mph and the last 4-5 weeks. Fuel economy is going down pretty fast. first 24-25mph them 23 and 22mph last fill up. Need help!!!
 

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I have posted that I noticed my gas mileage going down recently. I believe mine is a result of my car not getting into overdrive/lockup. Which I think is because of my torque converter going bad. I have posted on here a few times about it and I think people think they are not related. But I might be reading too much into some posts. So, I decided to google what symptoms of a bad torque converter could be. Low and behold I found that many places list one of the symptoms of a bad torque convereter as being a decrease in gas mileage. I also have other symptoms. But I think the gas mileage was the first thing I noticed.

I have a complaint in with Honda CS since I was told that what I am experiencing is normal for my car. I told them that if they are going to say that it is normal, then I want the person that says it is normal to ride along with me. So, they are having a regional manager come out to do a test drive with me in mid january. My last trip to florida my car averaged 18.8 MPG for the 2000 mile round trip. When I told the CS person that the reponse I received was that not all cars get the mileage that is on the window sticker. I informed her that I understood that. I also told her that when the car was new, I was able to get better MPG than the sticker on the window. I also told her that I would never have purchased a vehicle that gets 16 City and 19 HWY MPG. My car used to get 18-20 MPG city and 24-28 HWY.
 

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Good tip above about the torque converter. Are the RPM's the same as before? A faulty TC will cause RPM's to go high and so the engine will burn more fuel.

Also, check your air filter, or just replace it. Have you tried a different gasoline brand? They vary in the amount of ethanol. More ethanol means lower economy. Also, check your tire pressure is 38 PSI. It can drop with the arrival of the cold weather. That's the easy stuff.

I found that fuel economy suffers if the engine runs even a little cool. Have the thermostat checked. BTW, the temperature guage on the dash is not even remotely accurate enough for diagnosis.
 

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Yes. The proportion of fuel in winter gas is lower than in summer gas. So winter fuel economy will be lower.
 

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Oh, what's winter gas? Is it different from summer gas? Where can I find an "all-year-around summer gas gas-station" to fill up my tank with summer gas during the winter?
 

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Gas consumption goes up when the weather goes down because of the change in the density of air: As it gets colder air becomes denser, and for the same volume of air the engine uses more gas to burn all of the oxygen in it. I kept records of gas consumption and temperature for our previous car and got this over 5 years (L/100km in BLUE, temperature in Celsius in RED and inverted - colder is higher).

Consommationvstemperature.jpg

Nicolas
 

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Oh, what's winter gas? Is it different from summer gas? Where can I find an "all-year-around summer gas gas-station" to fill up my tank with summer gas during the winter?
Nope, not here in Mn/Wi. The gas stations get this all from the manufacturer.
 

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Nope, not here in Mn/Wi. The gas stations get this all from the manufacturer.
Same here in the Sun Belt (Georgia). We have different formulations in our gas during spring/summer vs. fall/winter here in LA East because of our smog problem. Maybe in AZ, NV or HI you can find "summer gas" all year round.
 

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I know it should be lower but not that mutch. I'm down to 21-19 now. Replaced termostat, old was working at 165-175 F should be 190 F. Lets see how it works?. Tire pressure ok, air filter new, fuel have done bouth combinations.
I have a 2002 Avalanche same trip still getting 17-19 mpg same as worm weather, same trip, same time, same speed just colder.
 

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***snip*** Replaced termostat, old was working at 165-175 F should be 190 F. Lets see how it works?. ***snip***
The factory thermostat is rated for 167F (75C). Some here have replaced it with a Motorad at 180F (82C). My Scanguage reads around 180F with the OEM thermostat. (Still confused by that. Wish I had read the spec stamped on the new thermostat.)

In addition to what you have checked, feel your rotors after a run for overheating that would indicate a dragging brake. Feel the parking brake drums too for overheating.

Agree that winter gas wouldn't decrease economy by 30%.
 
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