[Saritaka]

Hi,

I have a 2012 Honda Insight. I get between 44 and 48mpg driving on the freeway and around 38 to 43 driving in LA traffic. I went on vacation for 4 and a half weeks and I had my roommate turn my engine on for a few minutes once a week while I was gone. I'm not positive he really did do all that because my Insight's performance is completely different.

When I fill up my tank, my mpg takes forever to go up. It's used to only take a few miles of driving, but now I have to drive 40 miles at least for it to get to it's optimal mpg which is now only 42.5mpg. It's now impossible to get beyond 43mpg. What is going on?? Is it because my roommate wasn't turning my car on? Or is it some other reason like the same gas sat in my tank for a month?

I took my car to the dealership and they said nothing is wrong with it. Clearly there is something wrong, but they won't fix it.

Has anyone else had the same problem? Did the problem eventually go away?

 

[samwichse]

Did it sit for that time with the parking brake on? Maybe its binding/dragging?

 

[Jivko57]

that is a 2012 insight, better try on the g2 forum. 42.5 seems ok for gen2 and is very bad for a g1 insight...

 

[gilbertguy]

Yep wrong forum but aside from that here is my thoughts on it. I'm guessing that he did exactly what you asked for and only started the motor and let it sit and idle for a few minutes. It really needed to be driven for a few miles as the sitting idling probably didn't do anything to help put energy back into your IMA battery. Honda will never say something is wrong unless there is an IMA or CEL light on, has to have a code before they say it has an issue.

I'm guessing that your battery naturally discharged to a pretty low level while you were gone, hopefully after you drive it for awhile it charges the battery back up and you see better MPGs again.

 

[Saritaka]

MPG problems

Did it sit for that time with the parking brake on? Maybe its binding/dragging?

I followed the instructions in the manual. I left the parking brake off and I just put a brick behind the back wheel.

 

[Saritaka]

Yep wrong forum but aside from that here is my thoughts on it. I'm guessing that he did exactly what you asked for and only started the motor and let it sit and idle for a few minutes. It really needed to be driven for a few miles as the sitting idling probably didn't do anything to help put energy back into your IMA battery. Honda will never say something is wrong unless there is an IMA or CEL light on, has to have a code before they say it has an issue.

I'm guessing that your battery naturally discharged to a pretty low level while you were gone, hopefully after you drive it for awhile it charges the battery back up and you see better MPGs again.

Thanks, I hope my car goes back to normal, but I've already driven it for a tank and a half and it's still lingering around 41 to 42mpg. I called the dealership and I asked them what to do before I left and all they said was to turn the engine on once a week. When I asked if someone to drive it around, they said no. I guess those guys at the dealership are pretty useless.

 

[gilbertguy]

You could try to recalibrate the IMA battery and see if that helps. Disconnect the 12V neg terminal for 10 seconds, you'll probably loose your radio stations and might need the security code. Hook the neg terminal back up, start it up and in park rev the motor to 3500 RPM. Watch the IMA battery bars, you should see them slowly start rising and it recalibrates. On the Gen1 it will charge until it gets to 4 bars to recalibrate, not sure on the Gen2 how many bars to recalibrate?

 

[Cobb]

Get your starter battery checked. The original battery fails easily. Most use a group 51 to replace it.

Try resetting the computer by disconnecting hte battery for 15 minutes if you got your radio code and presets. Then connect the battery and let the car idle for 15 minutes to relearn the engine.

Check air filter to make sure no critters have made a nest, fil it with acorns, etc.