Greetings,
I have a '08 Civic with 6k miles. I have not been able to get the avg. mpg in the 40's yet. I have did everything that is possible. I have been hypermiling. I have changed my driving techniques over and over. I have took it to the Honda dealer. But they never looked at it. they always told me that the avg mpg is really around 35 mpg.

 

Check the level of your oil, if it's too full it could cause a MPG drop. Also check your tire pressure, make sure it's at 44 PSI for best MPG and treadwear.

 

Couple things...
- Welcome to the group!
- One forum's enough
- Where'bouts do you live? (City+State/Province is enough, no need to say 555 Somesuch Drive)
- Are you sure you're not accidentally filling up with E85?
- What's your typical drive like?

 

Is this a 08 Civic Hybrid? If so it sounds like you need to find a different dealership. Now, give us some more information. What pressure are your tires at? What is your average commute like? What speeds do you drive at? What kind of gas are you using? Does it contain Ethanol?

 

First things first...

Hypermiling will always deliver good results provided that we follow the techniques correctly. There's no better place to start than reading Tarabell's Article. I humbly recommend it as the "HCH-2 bible" for anyone wanting to meet and beat the EPA rating.

Hemisync is quite right in referring to your dealership as a big problem. If the dozens of examples before you are any indication, you are better off looking for another dealership as they are clueless about your vehicle even in the simplest of customer support topics.

I can assure you that if you read Tarabell's article carefully and take your time to really know your car and the techniques she calls for, your poor mileage will be a distant memory in no time.

Cheers;

MSantos