2009 HHR 2.2 - Poor Fuel Economy
12-05-2011, 03:45 AM
#21
New Member
Thread Starter
Join Date: 11-27-2011
Location: Canada
Posts: 10
So many variables that need to be addressed here. What you need to do is establish a true baseline before hitting the panic button. Here's some suggestions.
1. Check the pressure in your tires when they are cold and set them to the factory inflation spec.
2. Check and replace the engine air filter if necessary.
3. Remove all unnecessary weight from the vehicle, you'd be amazed how much incidental stuff collects over time.
4. Run the current tank of fuel through the vehicle, and then refill the tank.
5. Drive normally, don't try to hyper-mile because that'll introduce a statistical variable skewing the mileage reading.
6. Don't trust the DIC mileage readout, it can be off by 2-3 mpg.
7. Run a tank of fuel through and compute your mileage the old fashioned way with a pencil and a piece of paper.
If your mileage still is consistently low, then its time to dig deeper. As far as the algorithm used by the ECM when running E-85, its based on the information provided to it by a sensor in the fuel tank that measures the specific gravity of the fuel in the tank...that may be failing, but its too early to condemn it.
1. Check the pressure in your tires when they are cold and set them to the factory inflation spec.
2. Check and replace the engine air filter if necessary.
3. Remove all unnecessary weight from the vehicle, you'd be amazed how much incidental stuff collects over time.
4. Run the current tank of fuel through the vehicle, and then refill the tank.
5. Drive normally, don't try to hyper-mile because that'll introduce a statistical variable skewing the mileage reading.
6. Don't trust the DIC mileage readout, it can be off by 2-3 mpg.
7. Run a tank of fuel through and compute your mileage the old fashioned way with a pencil and a piece of paper.
If your mileage still is consistently low, then its time to dig deeper. As far as the algorithm used by the ECM when running E-85, its based on the information provided to it by a sensor in the fuel tank that measures the specific gravity of the fuel in the tank...that may be failing, but its too early to condemn it.
12-08-2011, 01:01 PM
#24
Senior Member
Join Date: 01-04-2008
Location: Long Beach, Ca
Posts: 2,366
My 2008 2.4 get about 17/18 if its all in town. Short trips and driving below 35 mph KILLS my mileage. Now with the work commute, it's 90/10 HWY/city. My average speed is 23 mph and im getting 22 mpg as an average. SUCKO gas milege.
10-21-2014, 12:48 PM
#25
New Member
Join Date: 01-14-2014
Location: arlington, tx
Posts: 16
Poor gas mileage
This old fogey has enjoyed lurking. But I'm not sure of proper location for my complaint. I'm in the DFW area.my mileage has been in the 21-23 range in mixed driving. Where should I start looking to solve the problem? Thanks
10-21-2014, 01:33 PM
#26
Banned
Join Date: 10-02-2010
Location: Port Huron, MI
Posts: 5,933
It may be a good idea to start your own thread, instead adding to the end of one. :) Perhaps it will draw more interest with a more recent Start date.
Also. What percentage of Mix are we talking? How much % city, how much % highway (and from what I hear, time idling due to accidents.)
Also. What percentage of Mix are we talking? How much % city, how much % highway (and from what I hear, time idling due to accidents.)
10-21-2014, 01:36 PM
#27
Member
Join Date: 02-20-2014
Location: na
Posts: 36
Ali, lots of good info in here so far. One other thing to check is if there is an exhaust leak anywhere from the engine to the cat as it could cause lower fuel mileage. Normally you would get a code too. Also, you should be able to hear an exhaust leak but I'm just thinking out loud. :)
10-21-2014, 02:21 PM
#28
Technical Moderator
Join Date: 01-23-2009
Location: Fredericksburg, Virginia
Posts: 24,697
So, start at your accelerator pedal. Proceed to wheel hubs, then spark plugs, etc.
10-21-2014, 02:32 PM
#29
Platinum Member
Join Date: 12-06-2009
Location: Alabama
Posts: 11,099
Ali, lots of good info in here so far. One other thing to check is if there is an exhaust leak anywhere from the engine to the cat as it could cause lower fuel mileage. Normally you would get a code too. Also, you should be able to hear an exhaust leak but I'm just thinking out loud. :)
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