about a month ago i had 2 new tires put on, all 4 wheels aligned, a tie rod done and a new egr valve.

before all of that went on i was getting 22.7mpg and now im getting 19.8.

i know its not a huge drop but from what i heard, everything i did should have greatly improved my mpg.

any ideas??

Maybe your gas station started selling E10 fuel.

Old O2 sensor can degrade fuel mileage as well. Plus old plugs and wires.

change the pcv valve, its 2$ at checker auto parts, fuel filter which i still have but havent put it on yet which is 15$, other wise yer foot is too heavy.

Are you allowing your car to warm up and that is what is wasting gas? If it is that cold, block 1/3-1/2 of your condensor with cardbaord. I found that the bottom of a case of water bottles fits perfect. I see 100 degrees on my scangauge about a mile sooner at 40 MPH and 175 almost 3 miles sooner. I only do this when the temps drop below 25. My trip home is almost 20 miles with the first 5 being 40 and the rest 60. This is at 1am when the streets are empty so my drive is very consistant. I start my car, wait 10-15 seconds and just drive nice.

i changed the o2 sensors a couple months ago along with the fuel filter and i had a tune up done which covers the pvc valve and i gave them the 103's and my msd wires to put on and the was done in the beginning of the summer.

and i do let my car warm up before i go.

i try using c/t as much as possible at about 60.

im not sure what else it could be

tires at proper pressure?

yup, i checked them the other day

Why are you running 103's? You're no where near that mod level. You should run 606's. or 605's if you HAVE to do it.

Is your car tuned?

i thought that 103's were good. and i was hopeing to get a tune when the weather gets nicer

103's are too cold. 104's is even pushing it, just got back to stock range plugs.

i thought the colder the better?

Colder plugs are good but only when needed. To cold of plugs may be fouling up and collecting carbon, causing poor spark which will cause poor performance while also hurting your MPG as well.

No, your car is not at the level where colder spark plugs are needed.

You can easily lose 3 mpg with winter formulated fuel and colder outside temps. Also warming a car up is somewhat unnecessary and contributes 0 mpg for that time. It is more fuel efficient to start and begin driving gently for the first couple of miles. Anyway the spark plug discussion is interesting - carry on.

i allways let it run for a little bit before i drive, because 1, it gives a small amount of time for the oil to flow all over the parts, because, if your car sits all night, all the oil flows to the bottom, yes it still remains lubed but i still like to have that piece of mind