Totally Disappointed by the Civic !

[phoebeisis]

Pturula,
Welcome.You will eventually get better-much better mpg than 25mpg on your commute.
There is some debate over whether modern cars actually "break in" and get better mpg when they are broken in. I think any break in improvement in mpg is much too small for you to measure. Besides, your engine has turned roughly 8 million times- it is broken in.

Get a Scanguage.It will show you that you will get about 40 mpg at 55 mph once the engine is warm. It will also show it guzzling maybe .4gph while idling until it warms up and drops to maybe .2 mpg idling once warm. It will show about 10-15 mpg when accelerating-even modest acceleration.
Once you get the hang of pulsing and gliding-in city driving-and holding a steady 55 mph when on the highway, you mpg will get to 30+.You don't have to turn the motor off the P&G, it is easier to just lift off and glide with the motor on.Some vehicles completely depressurize the AT when you lift off the gas, so you don't even have to put it in N. Check your vehicle-or ask here- to see if your Honda is one of them.

Get a Scangauge, so you can tell what you are doing.You don't have to go crazy on tire pressure- between door panel and max sidewall will work ok(maybe 35- 40 psi).

Luck
Charlie
PS At 55 mph-CC on- our Pilot-4400 lbs V-6 would get about 26mpg-your Civic will get 1.5X that easily.My 5200 LB 5.7 V-8 98 Suburban get about 24mpg at 55mph-with the(CC) cruise control on-no hypermiling tricks(other than 43psi).You should get about 40-42 mpg at 55 mph-level highway CC on, no wind etc.
PPS-The cold weather does kill mpg-a block heater might be a good idea.

[fanamingo]

Originally Posted by warthog1984

57-58mph will get you much worse mileage than 55-56mph. The reason is that VTEC-e and i-VTEC select cam profiles based on rpm. for VTEC-e, 57mph means the engine hits 2300rpm and switches from the economy cam to the gas-wasting power cam and FE plummets. i-VTEC is similar.

Originally Posted by phlack

I'll have to play around with what warthog said about 55-56/57-58 and switching in and out of iVTEC. I figured that would be the case...one MPH higher would kick it out of iVTEC, I just dunno where that spot is on the 8th gen.

i-VTEC on the 8th Generation Civic requires a warm engine, rpms between 1,000 and 3,500, and light throttle. Based just on rpms, you'd be able to stay in i-VTEC until 111 mph (16" wheels, automatic transmission). However, air drag will be too great, and you would exceed the engine load required for i-VTEC long before you hit that speed. I've posted more details in the following link in the Honda sub-forum.

i-VTEC in the 8th Gen Honda Civic

[St. Mushroom]

For a std. DWL accel, keep LOD way down and accelerate very gently. For a P&G routine, you can open it up some and bring LOD up to 70 + %. Warm-up P&G with is your way to higher FE but leave the high LOD pulses for after the ICE is above 160 degrees F.

http://www.cleanmpg.com/forums/showthread.php?t=26663