My civic is suddenly just geting horrible gas milage it went from like 270 miles on a tank to like 180 miles on a tank. I have a leak in my back left tire and i was wonderin if that would make tht much of a difference in my gas mileage (when it gets low). and I kno bein cold doesnt help it any but does it really knock off about 100 miles on a tank?

 

What type of transmission Civic?

You need to calculate precise mileage (miles driven/gallons burned).

Low tires can indeed reduce gas mileage. Keep them properly inflated.

Is the CEL ON?

When was the last basic tune up (plugs, wires, cap, rotor) done?

 

Its an automatic transmission and What is CEL? and i bought the car last april and don't kno when the last tune up was.

 

Check Engine Light (CEL), see link in my signature.

Give her a basic tune up.

 

The CEL is not on. and I have never tuned a car up what all do i need?

 

Go to the local auto parts store (or Honda dealer = more $$$$$$) and purchase basic spark plugs (NGK), plug wires, distributor cap, and rotor. Photograph distributor and wires so you know how to hook them back up in the correct firing order.

You'll need a socket wrench to remove spark plugs and distributor cap, and a screwdriver to remove the rotor. You may need to flick the ignition key to ON(III) to position the rotor for removal. Install the plugs and reassemble distributor with wires. Tune up done.

 

Thanks =)

 

Where do you live? Temp plays a huge role with these tiny 4 bangers.

In Calgary it can be 35C (95F) in the summer, and -35C (-30F) in the winter. Down around -20C I see a significant drop in gas mileage, close to a 25% drop.

In the fall and spring my mileage drops a bit as well since the ECU is confused by the gas stations switching from summer to winter gas and vice versa.

After my most recent tune up (same as Ron mentioned) I got an extra 2 mpg's.

 

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Make sure that your CEL works. Turn the key to ON (normal running position) but not all the way to actually start the engine. The CEL should come on but then go out after 2 seconds. If it doesn't come on at all, someone may have removed the bulb. You won't be aware of potential problems with the engine. This is fairly common on used cars.