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Discussion Starter · #1 ·
ok i live in South Dakota, its pretty damn cold here right now, I drive 100 miles round trip to work and am getting about 16-18 MPG, i have used regular gas, E-10....never E-85 and nothing changes, i have about 82,xxx miles on the car, i know winter driving causes MPG to go down, but that bad? i have checked the from 3 plugs last weekend and they look good, air filter is clean, change the oil on a regular basis, tires are at 32lbs.......im clueless what else i can check, i have ran seafoam in there about ever 5-6 weeks, so the injectors are clean....with the miles i put on, i thought that would be a good idea......any other checks or is winter driving just that bad? please help...if this keeps up, im dumping the car and getting a damn Honda....and i don't want that!!.
let me know.
Thanks
Colin
:gaah::gaah::gaah::gaah::gaah::gaah::gaah:
 

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dont buy a honda. ethanol in fuels in the winter wreck gas mileage along with cold temps. deal with it because in 3 months spring will be here and hondas are garbage.
 

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Discussion Starter · #3 ·
i hear ya, but even in the summer i was getting 23-24MPG...i had an ol 2000 impala with 180,xxx pulling 30-32 MPG....i cant imagine that big of a difference between a 3.4 and 3.9 to cause that big of a swing.....
 

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23 to 24 mpg isnt all that bad when you consider that the impala weighs damn near 4000 pounds. i average like 20 mpg but i have a lead foot in my 06 3.9 lt. i had a ford explorer before the impala and that thing would be lucky to get 16 mpg!
 

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Drive my 08 3.9LT and average 25-26 MPG, wife gets 26 as well on 06 LTZ 3.9. I will do 30MPG on a long flat highway run on the 08 with the cylinder deactivation.

Our 2000 3.4 Impala averages 25 MPG with 225K miles.

If you change cars, remember fuel is not usually the biggest expense!

Remote start? Lots of traffic lights?
 

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LIFETIME HILLBILLY
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have you done a tune up lately?
 

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There is nothing to tune up except spark plugs and filters. Plug wires if its really old, but I wouldn't worry about that. With the 3.5, I can get 25 mpg on the highway easy.

The big question is, how fast are you driving? If its not the car, its the driver. I know my Impala coasts for ever. Are you letting off the gas early when you have to slow down and letting the car coast? Are you driving 75 mph on the highway instead of 65? Lots of factors come in to play to get good gas mileage.
 

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Before you do anything expensive, id buy a thing of fuel system cleaner and then switch brands of gas.

On mine if i fun say shell, vs BP i loose mileage..


Also as you already mentioned the fuel in winter has a lot more aditives, which causes lower mpg..
 

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My 2012 gets way better than that!

Did you check the throttle body for deposits? It's helpful to clean the throttle body in late spring to early summer.

Manitoba gets colder than SD. Cold temp operation, especially town/city driving, will create a lot of condensation in the oil. That excess vapor will go into the intake due to the PCV system.

That, along with EGR operation, will create a sludgy mess in the intake runners and the back of the throttle body. There are dedicated sprays you can buy to clean the throttle body.

You have to remove the intake tube where it goes onto the throttle body. If the car has a cable operated throttle, have a helper floor the gas pedal, with the engine off. Spray the cleaner on the backside of the blade and use a shop towel to wipe off the sludge, and around the bore of the throttle body.

Don't spray too much cleaner. It will be almost impossible to start if you do. I like to use the air compressor to blow out the intake manifold before hooking the intake tube back up.

If you have an electric throttle, never ever try to move the throttle blade by hand. You could destroy the stepper motor that moves the blade. Have a helper turn the ignition on, but motor off, and floor the gas pedal. Spray the cleaner on the blade and gently wipe the stuff off. Wipe around the bore of the throttle body. Use the air compressor to blow out the intake before restarting the motor.

The mass airflow sensor can also get deposits on the wires that can kill fuel economy and even cause driveability issues. My '07 FJ I have to religiously clean the MAF every spring and fall. Only use a dedicated mass airflow sensor cleaner on the MAF wires. Never ever use a q-tip to clean the wires or you will destroy them.
 

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Mr. Handy
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^ Agreed there are many things that can decrease MPG

1. Dirty EGR valve or pipe
2. Dirty MAF sensor
3. " " Throttle body
4. Fuel filter
5. Plugs
 

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How are you checking the mileage? I mean by usual math, or are you doing by the display. If by the display it can get get confused. When i got 12 for the first 1000 miles it was showing 8mpg. Then the kids left something on and drained the battery. after it was jump started it showed correct MPG.
 
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