2005 Civic 22mpg

I have two 2005 Honda Ciciv LX Special Editions. No. 1 gets 31mpg
overall, No. 2 is usually 22 mpg overall, with a best tank at 25.8 mpg.
I purchased it used with about 14,000 miles and immediately noticed the
gas gauge plummeting, the needle going below E and the gas light came
on. A fill up was only 8.78 gal. Subsequent tanks had similar
problems, but fillups varied from less than 8 gal to as much as 9.8
gal. Recently the low gas light has been inconsistant. But what has
been fairly consistant is the gas mileage.
The dealer says there are no problems with the car. They have replaced
under warrenty the fuel sending unit and the gauge cluster. I have
suggested it may an emissions valve problem, but the dealership will go
only by the computer diagnostics.

 

Has anyone checked the air filter and other obvious mechanical stuff?
Is the car using much oil? Running OEM wheels/tires? Anything besides
mpg you've noticed about the car?

 

I do not know about the oil usage or air filter. The tire pressure did
get a bit low recently, however we have pretty much been on top of it.
The dealership did do diagnostics which should have shown a clogged air
filter. The only thing that they could come with was driving style.
But I cannot imagine a 8 mpg difference from the expected 30 mpg city.
My next step is to have the oil changed.

 

Actually, this is not true. Not unless the air filter is pretty much
blocked. Electronic diagnostics is a simple search for trouble codes.

The only thing that they could come with was driving style.

You may want to invest in a tune-up, too. Maybe have them check the
brakes, while they're got the car on the lift. Even with just 14K
miles, you may be well served by having a technician give the car a
thorough mechanical check.

 

In 6-02 I saw a new Civic vtec 1.6 litre with very short * : a waste of
vtec ( no way is torque / mpg esp @ high rpm maximised ).
www.turborick.com/gsxr1127/gasoline.html para 10.2(1) indicates
how bad a civic's * is. Many car makers ( incl Nissan in Sunny 130Y
, Hyundai in Sonata 2.4, Proton in Waja 1.8 ) save on *, because 99.9
% buyers have no chance to test drive on highways, or know /
experienced a difference between short & long branch *.
Honda fits only short branch ( 4 into 1 pipe ), cheap & heavy cast
iron * for its engines <2.2 litre
www.hondaautomotiveparts.com/auto/jsp/mws/catimgs/13sm40_d08.gif
, even a F22A's *'s twin pipes are short.
www.autozone.com/images/cds/gif/large/0900823d800cf8b3.gif
Results are lower though adequate torque @ low rpm ( as during
buyers' test drives ), but very low ( <½ as much ) torque & mpg @
high ( >3000 ) rpm : inadequacy increases with rpm. [ii] on highway
when >3000 rpm is needed, user cannot change gear from neutral to
drive w-o a jerk ; crank shaft etc. cannot spin fast enough from idle to

cars have long branch *. http://circletrack.com/techarticles/73598
My local-made 4-2-1 * uses aluminised mild steel [ii] is 13 kg
< original * [iii] has longer twin pipes than a F22A's * [iv] twin
pipes' interiors' total cross section area is 60% > original * ( single
pipe )'s.

Many ways to chk car / engine's efficiency, e.g. chk compression.
www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0c/f3/e5/0900823d800cf3e5.jsp

 

at 14k??? how much experience do you have with cars? seriously, please
tell.

 

enough to know that a used car with 14K miles could have been abused.

 

Both manual or both automatic transmission?

Are two different drivers involved? Can they switch cars for a while
to see if the poor fuel economy follows the car, or follows the driver?