I recently purchased a 2010 Equinox LTZ FWD with the 4-cylinder. I am very pleased with the vehicle except the fuel economy. I get only about 25 mpg on the highway at 65-70 mph. I also own a 2014 Chevy Cruze and I get over 40 mpg at the same speed. Yes, I realize the Cruze is a much smaller car with a much smaller engine but it is exceeding its highway rating while the Equinox is 7 mpg below its highway rating. Recently I took the Equinox on a 120 mile round-trip that was all highway. I recorded 24.5 mpg travelling at 70 mph. I have been trying to figure out why I have been getting such poor fuel economy for months by trying different speeds, using ECO mode, not using ECO mode, keeping the cruise control on, turning cruise control off but have not been able to achieve anywhere close to the highway rating, until today.
I live in Florida and have owned the car since April so it has been hot during my entire time with the car. I decided this morning to leave the air conditioning off. Even though in other cars I have owned, the AC seemed to only have a minor impact on fuel economy, I gave it a try anyway. I left the windows about half way down to allow for some air flow while keeping drag to a minimum. My back was soaked in sweat and sticking to the leather, but I was able to achieve 33 mpg! I was so pleased to actually exceed the car's highway rating. I also replicated these results later in the day.
Now I understand that running the AC does have a negative impact on fuel economy but this is a 25% difference! I get 40 mpg in the Cruze with the AC on high and a smaller engine running the compressor. This leads me to believe that there is an issue with the AC that is causing excess load on the engine. I also notice that when starting up the engine cold, with the AC on, it has a rough idle. If I put it in gear, it makes a rough 'grinding' type of noise. This issue only occurs with the AC on and when the engine is cold. If I turn the AC off, the engine immediately smooths out and there is no noise.
Does anyone have any theories on what is causing this issue and how it could be resolved?
I live in Florida and have owned the car since April so it has been hot during my entire time with the car. I decided this morning to leave the air conditioning off. Even though in other cars I have owned, the AC seemed to only have a minor impact on fuel economy, I gave it a try anyway. I left the windows about half way down to allow for some air flow while keeping drag to a minimum. My back was soaked in sweat and sticking to the leather, but I was able to achieve 33 mpg! I was so pleased to actually exceed the car's highway rating. I also replicated these results later in the day.
Now I understand that running the AC does have a negative impact on fuel economy but this is a 25% difference! I get 40 mpg in the Cruze with the AC on high and a smaller engine running the compressor. This leads me to believe that there is an issue with the AC that is causing excess load on the engine. I also notice that when starting up the engine cold, with the AC on, it has a rough idle. If I put it in gear, it makes a rough 'grinding' type of noise. This issue only occurs with the AC on and when the engine is cold. If I turn the AC off, the engine immediately smooths out and there is no noise.
Does anyone have any theories on what is causing this issue and how it could be resolved?
