Estimated mileage by the EPA is always very low, and it has gotten lower with the most recent changes. They are apparently lobbied by the dealers who don't want complaints from bad drivers. People who get worse mileage are always either driving incorrectly or driving under unusual circumstances. In your case it sounds as if you will have lower than usually mileage because you are driving in the hills, and mileage will be lower during the winter. You will also get lower mileage if you make lots of short trips. However, if you have only driven a hybrid 1600 miles you probably have not learned to drive it correctly yet as well. Rather than get mostly poor advice here from people who drive other cars, you should go to forums specifically devoted to Honda civic hybrids and also forums about getting good mileage (hypermiling). Another idea, if you don't mind spending a few dollars, is to buy a device such as the Kiwi from plx which helps you measure your mileage, learn to drive for better mileage, and also checks for engine faults.

Don't forget to inflate your tires. If you are driving through snow, all bets are off; just try to get there and back safely.

A few things come to mind here. First, you should be breaking to a stop at red lights and going down hills. Hybrids work by using regenerative braking. If you let aerodynamic drag do all your slowing down work, you wont be giving your battery the charge it needs to help you.

Another point is that hybrids thrive is stop and go traffic. You only get the benefits of the hybrids electric motor at slow speeds. Its sounds like you live in a more suburban area (I don't really know what the "hills" are like) so you wont be getting as much of a benefit as a driver in a city would (That said, driving in a city is still less fuel efficient than on a highway)

Finally hills are the bane of the hybrids existence. Cruising up a hill is a lot of work for the smaller than usual gas engine in a hybrid and its too much work for the electric to do all the time.

Some other possibilities include low tire pressure, a dirty air filter (very dirty) or some sort of mechanical problem.

Another issue is that hybrids don't do well in the cold. It increases the internal resistance of the batteries so they wont work as well while it is cold. And on the flip side, running the AC (and depending on the model, the heat) can drain power from the batteries and reduce millage.

A final point is that the EPA just revised MPG estimates this last year and hybrids took a massive hit. It had to do mainly with what they considered normal operating temperatures. It didn't make a big deal for gas powered cars, but temperature can hugely effect batteries.

I have driven a Civic Hybrid in the last three years. My gas mileage is about 42 in the summer and 39 in the winter. I live in a not so congested, relatively flat but high altitude, suburban area.

In addition to what other people have said: the use of engine braking and proper tire pressure, there are a few other things that may affect your gas mileage. Gasoline: I actually saw the difference between gasoline brands. Usually speaking, name brands yield 2 miles more than supermarket or warehouse brands (e.g. Costco). I am not sure if this is due to the percentage of Ethonol. Carrying weight: if you usually carry passengers, your gas mileage will drop significantly. If you have a lot of heavy stuff in the trunk, you should also consider if it is necessary. Wheel alignment. There was a recall on 06-07 Hybrid rear axle (http://www.usrecallnews.com/2007/09/major-honda-civic-recall-of-2006-and-2007-models.html). As part of the job, the dealer did a 4-wheel alignment. The gas mileage improved immediately. Weight of the wheels and tire rolling resistance: The OEM rim and tires are specially designed for hybrid. The rims are light. If you replaced them, you will see worse gas mileage. The OEM tires have low rolling resistance. Unfortunately, they are expensive and short in tread life. When you choose new tires, you should pay attention to rolling resistance number. I am assuming that you did not substitute the OEM tire size with something different. If you did, the difference in tire circumference can make the gas mileage calculation in the on-board computer inaccurate.

But since your car is so new, it more likely that the car has problem in it. Your low gas mileage is not due to lack of break-in. It is possible that the car suffered damage in the transportation process. If the car was not properly secured during transportation, the car can be out of alignment which causes low gas mileage. You should also check the wearing patter on your tires to see if there anything unusual. It is a good ideal to ask the dealer to check it up, from engine to alignment.

The 45 mpg estimate is based on tests conducted by the Enviromental Protection Agency (EPA). You can read some of their technical documents here on how they performed and evaluated their results:

http://www.epa.gov/fueleconomy/420r06017.pdf

In addition to some of the conditions you may find that the EPA does to come up with their numbers, they may also not be relying on the digital instruments Honda displays at the dashboard. Instead the EPA may use consistent measurements of gas supply and external measuring equipment to avoid results that may be inaccurate from vehicle to vehicle.

Rather than relying on the avg MPG displayed on your dashboard, try the traditional method of measuring fuel used given a specific distance calculated by an indpendant GPS device or accurate mapping tool.

Visit the following website and enter the following information:

http://www.hondacivicrepairs.com/saving_gas.asp?q=Saving%20Gas%20-%20Honda%20Civic&id=17

1. First, fill up your gas tank to full.

2. Reset your trip meter (next to your odometer) on your dashboard to 0.

3. Travel 100 miles or more (the more miles the better). Try to isolate driving between traveling on highways/freeways only and street/intersection conditions.

4. Then refill your gas tank to full and enter your values and click on calculate.

Good luck!

Estimated gas mileage is measured under ideal laboratory conditions. In the real world, gas mileage is not expected to measure up to the advertisements, but because you are getting about half of the advertised gas mileage, you probably have a lemon. Check out this link, http://www.lemonlawcenter.com/hybrid-gas-mileage.htm,and if the fine print used similar language, then call 1 (858) 270-7000.

Companies always over estimate in advertisements, and they are talking about the best case scenario. They are not thinking about the average driver, or the driver who drives quickly, or has a heavy foot, etc. They also probably are only referring to flat road and course road driving, not taking in consideration the hills in Pittsburgh. So, yes the hills in Pittsburgh may be the reason you're not optimizing your mileage, but also it could be your driving. Sometimes people are not able to correctly analyze how they drive, so you saying no "jack rabbit" starts is just your thoughts. This is probably true, but then again you may be driving it heavier than you think. My best suggestion, since it's a new vehicle would be to take it back to the place where you bought it and ask them. It very well may need to be break in miles, and then it will get better mileage.