your car does not have OEM tires at 98k, so I would fill them up to 35, what does the sidewall of the tire say? Just don't go above that., I never seen 30 on any car so that's weird. But find out what maintenance was done and what was not.

And how are you calculating? you writing the your odometer when you fill up, then when you refill up write down how many gallons you filled up with and write down the mileage then figure out your MPG.

 

Smitty, I might have spoken too soon. Cleaning the throttle body is fairly easy and a common thing.... the sensor is another story. Most folks will tell you not to do it as it can be easily damaged if done incorrectly or if done at all. I'm not sure what is in our cars, if it's the Bosch planar or some other sensor type. I'm used to the one in my old Volvo, which could be cleaned. Ours, I'm not sure and maybe someone else with much more info can answer this.

I used CRC brand QD electronic cleaner. The mechanic that taught me this would sometimes use gasoline or a torch to heat the carbon tip and burn it off. These are not my suggestions for ours.

Again, sorry for having spoken too soon. Some can be cleaned easily and others can't.

Hopefully someone more knowledgeable can answer this.

 

Ill go fill my tires to 35 psi asap. Thats exactly how I do it. And I usually refill right when the gas light pops on.

 

I'll research both these ideas before I make any moves! Thank you very much!

 

hmm, hows your foot? ha, City is brutal for MPG. Going too light on the gas can net you worse MPG then giving it a little and getting up to speed a bit quicker.

 

Does the car has rebuilt title?

how clean is the air filter? what about try to replace the fuel filter first? have you try to rest the ECU? have you try to seaform it? have you check alignment? is the engine oil clean and sufficient? how did you calculate your mpg?

 

I have an 06 with 40K miles and I usually get about 200-230 on a full tank but I refill around 180-200 .. I have a new engine since 7000 miles ago but I do nothing but city driving .. my screen reads 12-14 mpg all the time and I'm getting the same numbers basically as you with full tank mileage .. these cars are just gas pigs to begin with but some people are lucky enough to have more highway miles on their car instead of being stuck in amazing Jersey traffic and never really stretching the cars legs on the highway .. I don't drive to conserve my mpg though .. if you REALLY are getting 10 mpg how do you know you're getting 200 to a full tank ? you'd literally have to drive until the tank is fully empty to ever see THAT number .. at what mileage per tank are you refilling and where is the gas gauge when you do so ?? do you see the gas light on and then refill ??

 

That is quite low. I have 40K on my '04 Coupe 6MT, and I have never gotten worse than 20 MPG on any tank of gas, regardless of how hard or what kind of driving(city/highway) i have driven throughout the duration of that tank. I average around 22.5 to 23.7 MPG on the majority of my tanks of gas. Sometimes I drive light, but I also sometimes drive aggressively. Even when I drive aggressive after a fillup and have just reset my navigation system's fuel economy thing, I still never get worse than 16 MPG during aggressive driving stints.

 

I get about 240 miles a tank on average. Driving 5 miles to work each way.. 50% city 50% highway.. I have a pretty heavy foot. I fill up when the light comes on, ususally takes 16+ gallons. But I don't see how anyone gets 400+ miles a tank.. not sure I would ever be able to get that in my car.

 

Wow I thought I got bad mileage in my sedan. I can sometimes push it to 350 miles on a tank. I was getting bad gas mileage but the CEL was on. The autoshop that installed my spark plugs unplugged the o2 sensor and forgot to plug it back in. Now I'm getting much better gas mileage.

 

im just curious to know how many gallons do our tanks hold anyway? I never let my car go lower than half on the guage

 

20.5, if I'm not mistaken.

 

Rebuilt title? NOPE title is clean. Air filter is clean. I'll go ahead and replace all my filters and see if I isolated my problem. How do you reset the ECU? I plan to seafoam in 500 miles right before my oil change. I'll also check alignment when I go in for my oil change. The engine oil looks good. I posted above how I calculated my MPG.

Should I just change my filters, oils, etc. myself or just have a my maintenance man do it? (gonna cost extra of course) I've never done any of them and don't know if its worth the "risk" of doing it all myself. I'm confident I can do it all

 

Above I posted I dont drive hard at all. Practically babying it. My driving conditions are mostly rural areas. I dont need to stop n go a lot at all.

 

Usually when I refill, I had the gas light on for quite a while, maybe a few days. Sometimes I try not to but it depends when I get my paycheck and ****.