Others may have said this before. The bars in the fuel level indicator are estimates only. They do not give a precise reading. You must calculate your fuel consumption and your miles driven. Do this for a few weeks.

 

I still think you should explore if the engine is getting fully up to temperature. My wife's Volvo's t-stat failed open a few years ago. It became obvious when she noticed she had to fill up more often than she used to. The engine wasn't completely warming up which made it run less efficiently. It was similar to yours: she lost about 1/3 of the range for a tank of gas. The temp gauge was useless because it basically moved to "normal" as soon as the engine was around 150 deg IIRC. I know my AP1 reads normal as soon as the temp gets to 160. (Note: Modifry has a real nice hack that reestablishes a normal range for the temp gauge where each bar represents another 15 deg).

As I said earlier twice, the simplest way to check is to put a bluetooth OBDII connecter on and use Torque app on your phone to see what the temp really is. A failed IAT can also cause similar symptoms depending on what the failsafe temp is in the ECU.

BTW, I've mentioned this three times now so won't bring it up again. But you were frustrated earlier that you weren't getting suggestions and this one is pretty inexpensive and simple to do.

 

You don’t have to mention it anymore. I’m gonna go ahead and do this.

thank you

 

Does the car feel normal? Any hesitation, stumbling, etc.?

 

S2000's run very rich when they start up. Avoid short trips.

Are you warming the car up before you drive off? Don't do that.

Those two things can attribute to shitmileage.

Combine that with winter gas (if your state switches to butane-gas)...and you've got even more shitmileage.

18mpg is probably lower than one would expect.

Note that you did post useful info by showing the progression of your tank.

Also remember that I was the only one that didn't make fun of you. Because I, like you, am a forward thinking hero.

Your highway bar use was slow.

Your bars dropped faster after your suburban stint. So you're likely warming up the car and taking short trips in them burbs. no?

 

Haha, thank you.
I did notice that while driving on the highway, the bars took a while to drop compared to the suburbs. Then again, I heard the lower half of the bars dropped significantly faster than the top half. I did make a lot of short trips. I drive every morning to school which is about 4-6 miles and back in the afternoon.

 

Dont really feel any of that. I had done the shifter regrease maintenance, that made the car feel better. Car feels slower for some reason but then again, it’s a s2k

 

I just did a long two lane drive on Sunday. The total trip was something like 250 miles give or take so I ran through almost a whole tank. I got 24.4 mpg on that drive which was mostly composed of lightly spirited driving between 4-6k RPM and some occasional full throttle bursts to close to redline as well as some occaisions of cruising easy behind slower traffic. I have a flashpro and don't really recall my MPG changing much if any after the tune. I do recall seeing my gas gauge at at least 3/4 tank or like 6-8 bars above half tank after driving 101 miles after fill up. That struck me because I recall seeing your pic at half tank under similar mileage and thinking, "Oh damn, his mileage really was bad" and "man, I was kind of hard on him"...lol. So sorry if I was a hardass earlier. I hope you get this sorted out.

 

no problem man. That was my intention of posting pics of my tank so people can compare.