Gas guage hits empty way faster than it use to

[01cobravortech]

By the time I hit the 1/4 on the nose, I have gotten between 180 - 215 miles. If you're getting 70miles on an almost full tank witht he empty light going on rollseyes ) then maybe you're driving a Ferrari Enzo.

 

[01cobravortech]

I just filled up on Sunday, and I did some STFT tuning on Monday, and I am just now barely left of the F, and I have 40 miles on this tank so far. I usually see about 110 miles on the first quarter, 175 miles by the half way point, 210 or so by the third quarter, and if I let the low fuel ding come on I am usually sitting at about 255 miles or so. ( I never run her hard with less than three quarters of a tank) This is with very inconsistant and spirited driving. And when I fill up I usually put about 13.5 gallons in if I let it get that low.

Now, if I am hard on it for a full tank of fuel I see maybe 220 miles to the tank at the most, and if I am easy on it I can see as much as 275 miles to the tank.

This is just me recalling from memory. My figures could be a bit off, but the MPG and total miles per tank is correct.

-Jeff

Your MPG reporting is eerily similar. The best I've seen with minimal boost was about 250 miles, but that was letting her get below a 1/4 of tank. I don't like doing that since the gas tank design causes the fuel pumps to heat up since the fuel level is too low to keep them cool during operation.

 

[mavereq]

my car has been running a bit off lately. it has a miss at partially open throttle and i can't seem to diagnose it.

since that started my mpg has really gotten bad.

 

[SnakeBit]

I'd add the O2 sensors to everything else to check. Check for a broken/melted wire. It's not unusual for a sensor to go out in 29,000 miles.

Also, you mentioned pullies, but what about a tune? At the very least, get it on a dyno with wideband. I suspect it's running real rich. And check/regap your plugs.

Also, you said it was stored. A mouse could have chewed some wiring.

 

[xenodragon]

I surrounded it with mouse traps with an outter circle of moth balls hopefully the mice werent smart enough to bypass the traps to go chew my wires

I was running spot on air/fuel with my last dyno about 3 months ago. It was actually running a bit lean ~12.5ish if i recall from my dyno slip. Im still going on my first tank but it seems like by the time the tank goes empty I will be right around ~200 with me jumping on it every so often....i bet i just had some bad fuel when I made my first post..i dunno. Will post final numbers later

 

[ViciousJay]

curious, maybe a dumb question but can a car thats running rich or on a very conserv tune kill mileage even when babying... ive never been able to get better then 210 and thats babying it.. staying under 2K and everything :shrug:

 

[HISSMAN]

If you are running rich in closed loop (part throttle) then yes, you will see crappy mileage. There are a lot of little things that can be done to increase mileage.

 

[HISSMAN]

FYI, I have been blasting the hell out of mine on this last tank, and I just crossed the mid-point, and I have 150 miles on the trip-odometer. I will probably clear about 200-210 on this tank.

-Jeff

 

[ViciousJay]

If you are running rich in closed loop (part throttle) then yes, you will see crappy mileage. There are a lot of little things that can be done to increase mileage.

like what... curious cuz im looking at getting a retune after i install a lower...

 

[HISSMAN]

Your tuner should be know how do do this. Just tell them not to focus 100% on the WOT pull, but you also want good driveability as well.

-Jeff

 

[ViciousJay]

Your tuner should be know how do do this. Just tell them not to focus 100% on the WOT pull, but you also want good driveability as well.

-Jeff

ehhhh id rather sacrfice gas instead of power... :-D its ok with me .... id rather be safe in the higher RPM's

 

[03cobrawannab87]

uuuuuuuuuuuuh, you got like a hole in your gas tank. or some bore bum sucking that premium out.

 

[HISSMAN]

I get great fuel mileage and power. A good tuner will tune all aspects of driving. From idle to cruising at 2,000 rpms, and even the WOT blasts. Tuning for better fuel economy will have no effect on your power at WOT. You have to look at it as almost being two completely different tunes. It may cost more and may take the tuner more time to get everything nailed down. But, with today's fuel prices it could pay for it's self in a few fill ups if you are able to increase you mileage by 2-4 miles per gallon.

-Jeff

 

[Red Turtle]

My needle was touching the E and I filled it up and it only took 12.1 gallons... This gauge is funny though, from F to 3/4 you think that your are a hero then it starts to drop like a boat anchor!!! It is a lot different than my 05', as I could drive for 2 days on a 1/4 tank.

 

[SoCalHarley]

The mileage with these cars differs dramatically between highway and arouind town driving. Highway I can see 20+ but aroud town I rarely see over 13, usually between 12-13. I bet if you guys just did local driving with no cruising you all would see about 13 or so mpg. The best I ever did around town shifting at 2000 rpm was 14. I do get on the car quite regularly...

 

[01cobravortech]

Finally was able to average 20mpg after having a 270 mile trip I had to complete. I accomplished it with 70 - 80mph driving. But I barely used any boost at any point in time during the trip. That kind puts in perspective what needs to be done to get 20mpg.

 

[CobraKraiger]

I'm usually at about 225 miles just at or under 1/4 tank. I try to filler up by 1/4 tank.

Same with me

 

[gotboost03]

12-14 in town is normal 18-20 on the highway is normal as well unless you put your foot in it. This is the first car I have had that operates this way. Full to 3/4 I can go 100-150 miles and from there forget it I can watch it move every min after that.

 

[SicStang03]

I checked and I was averaging 15.1 mpg, and that was with my foot in it a lot.

+1

 

[fearthesnake]

Geezz... that's great mileage Virginiafiveo...

uhhh,....you sir have a problem.....I got 388 miles on one tank (had an 1/8 of a tank left) on the trip to wilmington I just made. 75-80 MPH 6th gear all the way with intermittent AC use and no boost.

Comes out to around 28 mpg Highway... best I could ever get is around 23-24 mpg on a complete highway run at same speeds.

But I agree... definitely a problem here.