fuel gauge woes

houkouonchi

I just got a brand-new 2010 370z. It had 8 miles on it when I got it. I am now a little bit worried as I have seen some weird behavior with the fuel gauge.

The first time I got gas was just after the light came on and it got down to the last two dots. I got gas shortly after this happened and put 16.8 gallons of gas in the car.

The second time was again when it go to two dots and I waited a bit longer this time and put 17.2 gallons of gas in it.

This all seemed normal. Well flash forward to just yesterday. My car has 1100 miles on it. I was driving from one data center near LAX airport to our other one in downtown Los Angeles. Right as I was leaving the one in LAX the gas light came on. I figured I could go ahead and wing it until I got to downtown and then later on my way home go to a gas station that was out of expensive L.A. (about 28-30 miles from where I was at that point). The DTE was at 60 miles.


So I drive to downtown and surprisingly in only 16 miles the gas went down to 1 dot just before reacing my destination. This was quite odd as It was almost completely highway and I got around 24 MPG. I figure its nothing to worry about but after I finish up my shift and start the car I see the DTE is now --. Another 2 minutes when I am leaving the parking lot all the sudden the car goes to 0 dots (not even registering anymore). This got me quite worried as the last two dots went away in less than 20 miles when I had almost put that much on before after letting it go a bit after two dots in the past and it never even got to one.


So I decide to go to the nearest gas station that is downtown L.A. and pay 25 cents more per gallon. It wasn't worth it to make another trip to a gas station so I took the $3-4 hit and filled up the tank.

Now this is where it is weird, it only took 16.8 gallons to fill up the tank. Wtf? It was on 2 dots before and I put 17.2 gallons in it and this time it was at no dots and I only put 16.8? Obviously I could have waited until I got 10-12 miles out of L.A. and went to the usual place I go.


Is this just typical shitty digital gas gauge or do I have a problem? I know one of the only problems my dad has had with his 350z has been his (analog) fuel gauge. When he fills up it only goes up to like 75% full.

It seemed to work just as I would expect the first two times I got gas and now I am seeing weird behavior so I am getting a little worried.

Daishi

Mines always been like that. As soon as the gas light goes on the gauge drops quickly. It probably does that to scare you into getting gas asap. All the cars I've had as soon as you hitthe red on the gas gauge it would always godown much quicker. I wouldn't worry about it.

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TongMan

That gas guage is just there to tell you to go fill up. It's not a universal accurate measurement of the exact amount of gas you have in your tank. Plus do not depend on it to measure the same everytime.

spearfish25

Are you doing anything differently when you fill up the car? If you 'top it up', you can squeeze almost another half-gallon in the tank. Also, don't think that every gas filler handle will turn off at the same level. None of the instruments we using in refilling are that accurate. Except the cost calculator in the pump itself...that reads thousandths of a dollar.

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Matt

If we've learned anything about the fuel gauge in our 370z, it's that the "xx miles left" warning isn't very accurate. Best advice is to fill it up before it gets down to 0-2 dots.

Also, I've never filled up with more than 17 gallons of gas, so I think either the 19 gallon tank is wrong (not likely) or the gas gauge is erring on the side of caution (most likely).

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Modshack

Don't let it get that low (the fuel pump is in the tank and cooled by the fuel).

Also, put a bottle of Techron in every now and then. It will help keep the contacts on the fuel gauge sender clean and read more accurately.

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KillerBee370

You're putting way too much stock in electronic gadgetry.

houkouonchi

Well I am a computer geek so figures =P I have graphs and sensors for pretty much everything on my computers (even room temperatures in my house =P )

I guess I know to take it with a grain of salt when it starts getting low. I do top off the tank when I get gas.

Btw I am replying to this thread courtesy of the dealers wireless network =) I finally got over 1200 miles on the car so I took it in for the complementary oil change. I cant wait to drive it home now that its out of break-in =)

I also read through a bunch of that huge thread about oil temperature problems. Is that still an issue on 2010s? When driving to the dealer my oil temp got to 240 F which seemed a bit high to me since I wasn't pushing the car at all (about 80 mph highway driving). I will admit it was hot out though (106 F according to the cars outside temperature gauge).

kenchan

We have too many houkouonchi Canadian goose here. Please take them back.

spearfish25

I would swear that Techron made my fuel gauge go wacko. I was doing fine, then put in a bottle of Techron. For the next 5 tanks, my two right-most LEDs on the gauge would sporadically stay off despite a full tank. After about five fillups, the gauge is working fine again. Bad batch of Techron?

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sonic370

iv'e seen my oil temp get to 220 here in texas on a hot day. i try not to get in behind 18 wheelers or other traffic. to me the oil temp gauge is more wacky than the gas

PapoZalsa

I never let the fuel gauge on any of my cars go under a 1/4 tank.

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spearfish25

Your gauge is working fine. Put in an oil cooler and watch where it settles out. I'm amazed at how nice and cool my engine has been since I installed mine...and it's been a constant 90F+ here.

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houkouonchi

LOL!

I thought those suckers had metal in their beak's or brain or something which made them 絶対方感 (zettaihoukan). My made up antonym of houkouonchi, comparing onchi to zettaionkan as I don't think there is an official/real antonym to houkouonchi.

I know its extra confusing being , CA but I actually live in Ontario, California, not Canada =P Yeah I know the CA makes it even worse, HAH! It was a lot less confusing when it was Shibuya-ku, Tokyo, Japan.

billydsz

Well you are making the assumption that the gas meters on several different gas pumps are all going to be exactly the same which they won't be. So that's another source of error.

Regarding tank size, most manufacturers assign a reserve at "empty" of a few gallons so when the tank reads empty you still have a little time to get gas.

Gas tank gauges are always fairly innacurate I wouldn't lose any sleep over it. Don't forget the gas is moving around in the tank too so the gauge can't be too sensitive otherwise it would be moving all over the place as you drive.