oonowindoo

it s been like this since i bought my car... let s say
i have exactly half tank left when i turn off my engine .. and after a few hours when i turn on my engine again.. it s not half tank anymore.. it s like 1 small section under half tank..... i know this should be normal but it never happened to my other cars..


and i have another Question.. TL and CL have the same rim offset right? if the rims can fit on TL then it would fit on CL also?

EricL

Haven't noticed the gas movement.

Could it be due to heat in the gas tank (change in volume with temp)?


As for the TLS/CLS -- I believe the offset is the same. The TLS get the 6.5" wide 17s in the US vs. the 7" wide 17s for the CLS.

Nashua_Night_Hawk

same obeservation... do not know why in the world we do not get digital gagues for the gas tank.... at least let them make it acurate....

Tuboz

the car eats most gas when first started....multiple starts used to kill my gas like you have described above...i also notice this in my S2K....

-tuboz

32vv1ll

i think its normal, my car does the same thing

CO-CL-S

Unless they took the temp. of the gas (and had a processor to adjust reading), digital guage would show the same thing..

mickey3c

I have had problems with my gas gauge not reading the proper level of fuel. It would go just over full when I filled the tank. Then one day it would not, it would be like one hash mark below. The sensor that sends this information to the instrument cluster was changed. It was located on the gas tank.


It happened on my 99 TL

Rod

On a related note, do you guys think the slight rake the Comptech springs give the CL affect the gas gauge reading?

Nashua_Night_Hawk

another observation... the CLS feels faster when the Gas tank has been filled to the rim... driving on the E line, it feels as if the CLS is going to stall.

Pappy

Do you park on a hill?

oonowindoo

_____________
Agree, that s y i have been thinking how can people get faster times with empty tank than full tank i know it s lighter but full tank feels faster than empty tank to me.

and no i dont park on hills

my avalon never did this... maybe because CL's gas needle goes all the way down when i turn off my engine and avalon stays

EricL

If you look, the mufflers are rather close to the gas tank. Fluids (gas) expand when they are heated. The tank sensor in my last car used a sensor that was VERY temperature sensitive (so it was sensitive to temperature changes too. I need to look up the temp coef of that material used in that older car’s sensor, but…)

Phenomena:

Gas needle is up after a run, needle down after sitting around (two or more people say they have seen this). Let’s assume that this is happening for “some” people.

Want to help prove a possible theory?

Just run the car for around the block and see where the needle sits (hopefully, this is not long enough to heat up the tank enough).

1. Drive 1/8th mile (verify needle position).
2. Leave for hours or overnight (whatever you decide on). Check needle position.

REPEAT TEST doing a much longer run.

1. Drive your normal and longer route. (verify needle position)
2. Leave for hours or overnight. Check needle position.

Now, see if the difference on "restart" is as great as the difference on a longer drive.

I am assuming that a short run will not heat the gas up very much (1 block run).

There is a simple answer that could depend on a few "trials"/"tests"

YMMV

AcuraTLSFan

I think the measurement device they use for the gas tank is somewhat the same concept of the ball/ballon in your toliet tank....when the ball is in the high position it will read full, and bottom means low.

So when your car is inclined or declined it will give you differnet measurement.

The comment on the gas tank being close to the mufflers...well most of the mufflers on other cars are usually in the same position. Heat may be a factor, might heat up the liquid gas into vapor...effecting the gauge?

I remember reading somewhere that after time, water will start to get into the gas tank....this have something to do with it?

EricL

OK, here is the data for how much gasoline expands with temperature:

" By far the most meaningful difference in the way gasoline is sold in Canada relates to the concept of "Volume Corrected to 15º C". The volume of gasoline, propane or diesel fuel, like that of any other liquid, varies according to its temperature. A brochure published by Industry Canada's Weights and Measures Division entitled "Volume Corrected to 15º C" states, in part "..the technology that works as follows: A temperature sensor continuously measures the temperature as the fuel is being metered. It transmits the readings to an electronic register, which automatically selects the right correction factor and applies it to the amount of fuel to calculate the volume at 15º C. So, when you see the words "Volume Corrected to 15º C", you know that the volume of energy your fuel dollar buys is not
influenced by the temperature of the fuel."

Gasoline volume changes approximately 0.125% for every 1ºC change in temperature (0.058%/ºF) . The energy content of a gallon of gasoline purchased by a motorist in Nome, Alaska in January could, theoretically, be as much as 8-10% greater that that of a gallon of gasoline purchased by a motorist in Phoenix, Arizona in July. Although temperature extremes in Canada would be far less than this example, attention to the effect of temperature on energy content of a given volume of gasoline has resulted in voluntary volume correction of most gasoline sold in Canada to 15º C....

I PROMISE you that the mufflers are going to heat up the fuel. Look at the tank and were it sits relative to the exhaust. And that's just one source of heating.

You can measure volume using:

1. Float type sensors.
2. Ultrasonic sensors.
3. Add yours here.

BTW, there is a common suggestion to buy gasoline at the coolest time of day (or when the gas is coolest). Think about this:

"Buy gasoline during coolest time of day - early morning or late evening is best. During these times gasoline is densest. Keep in mind - gas pumps measure volumes of gasoline, not densities of fuel concentration. You are charged according to "volume of measurement".

If the tanks were not buried in the ground, where the temperature stays relatively constant, you could find yourself getting ripped-off by buying gas from an above ground tank exposed to high ambient temperatures...

thorin

when ya got a full tank, its gets the weight closer to the goal of a 50/50, although are cars don't even come close, just closer....that's why....more balanced....