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      10-08-2013, 03:03 PM   #1
914kidd
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Inaccurate gas gauge

My car usually gets 380-450 miles to the tank depending on the type of driving I do for that week. Most of the time I don't even hit boost .

I filled up two days ago and when I got home yesterday it was still showing almost full tank of gas. This afternoon when I went out for lunch (same roads/route/driving) I am almost down 1/4th. I was watching the gas gauge go down during my morning commute and when I went to get lunch.

I stopped to to put in $5 gas on my way home just to see something, $5 is not even 1.5 gallons and when I started my car it was almost full again.

Has this ever happened to anyone? I don't think 1.3 gallons is enough to go from 3/4 to almost full 4/4. I do have a small exhaust leak and my low fuel pressure sensor is also out. Those things related?

Last edited by 914kidd; 10-08-2013 at 03:15 PM.
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      10-08-2013, 03:13 PM   #2
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Well depending on where your exhaust leak is it could be telling your o2 sensors that you are leaning out and that would cause the car to dump fuel.

Low fuel pressure sensor out HMMM not sure but doesn't sound good LOL

You can also check your tune and make sure your gauges are configured correctly.
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      10-08-2013, 03:17 PM   #3
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Well depending on where your exhaust leak is it could be telling your o2 sensors that you are leaning out and that would cause the car to dump fuel.

Low fuel pressure sensor out HMMM not sure but doesn't sound good LOL

You can also check your tune and make sure your gauges are configured correctly.
My exhaust is actually leaking from three places where a terrible shop did a resonator delete. I am waiting for my new xpipe to come and my tips before I get it fixed.

I realized that even in a "highway" commute I hit 9/10 traffic lights that are 3-4 minutes long so I guess MPG can still suck even if you do 90% highway driving but get stuck at 10% of the lights. Today I hit every light each time I went out.

My tune is map 1 on JB4 I usually run it very conservatively. I also did the Alpina flash so the car gets in 6th gear at 40 mph and and needs more throttle push going uphills and I live in a hilly area. Perhaps the flash is why the mileage is suffering, I just did it Saturday.
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      10-08-2013, 03:36 PM   #4
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Quote:
Originally Posted by 914kidd View Post
My exhaust is actually leaking from three places where a terrible shop did a resonator delete. I am waiting for my new xpipe to come and my tips before I get it fixed.

I realized that even in a "highway" commute I hit 9/10 traffic lights that are 3-4 minutes long so I guess MPG can still suck even if you do 90% highway driving but get stuck at 10% of the lights. Today I hit every light each time I went out.

My tune is map 1 on JB4 I usually run it very conservatively. I also did the Alpina flash so the car gets in 6th gear at 40 mph and and needs more throttle push going uphills and I live in a hilly area. Perhaps the flash is why the mileage is suffering, I just did it Saturday.
You have a handful of things going on so I would not expect ideal gas mileage.

The exhaust leaks need to be fixed ASAP.

Your gauge is probably tweaked out by the LP Fuel Sensor. (I'll be honest though my expertise with that sensor is not much).

The alpina flash going into a 6th gear does sound a bit aggressive. As you may or may not know boosting just 1-2 psi waste significantly more gas then just being in full vacuum.
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      10-08-2013, 04:01 PM   #5
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Quote:
Originally Posted by Jeff@TopGearSolutions View Post
You have a handful of things going on so I would not expect ideal gas mileage.

The exhaust leaks need to be fixed ASAP.

Your gauge is probably tweaked out by the LP Fuel Sensor. (I'll be honest though my expertise with that sensor is not much).

The alpina flash going into a 6th gear does sound a bit aggressive. As you may or may not know boosting just 1-2 psi waste significantly more gas then just being in full vacuum.
Yeah I have been watching my realtime mpg display lately to get an idea of what is going on. It seems like being in low rpm and trying to mildly accelerate is much worse on gas than being in a better rpm range and accelerating the same amount. I think its using less boost if any in the proper gear and thus its using less gas. When you lug it even a little bit the mpg drops straight down to 6mpg which seems to be the lowest number it will read out If this is all true the alpina D mode will be total shit for mpg
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