Mystery Fuel guage

Chat about your MKI or MKII Polo (86 and 86F)
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Mk2Adam
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Mystery Fuel guage

Post by Mk2Adam »

i was looking in my haynes and it says my fuel tank should hold 42 litres, whereas my car takes £10 to go from the redline to halfway, then another £10 to the top....surely that makes it about 25 litres? hopefully it is my guage and i can fit more in cause that extra 17 litres would come in handy if i do a long journey. not major but just curious :)
GroovyCarrot
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Post by GroovyCarrot »

If it's anything like mine, the bottom of the red line will actually only be about 2/3 of your fuel.. there's a huge amount in reserve. The most I've put in my tank is £38, by which time I recon is was just about running on vapour. Takes strong nerves to run it off the fuel guage for that length of time though :D
SteB
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Post by SteB »

usual job with polos, the gauges are just crap! My mates mk3 polo lied even more than my mk1 - he could do about 200 miles on the first 1/4 tank, then it used to plummet!

Apparenlty its best not to let the tank run right down anyway - prevents rust and crap at the bottom entering the fuel filter
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SpikeyG40
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Post by SpikeyG40 »

SteB wrote:Apparenlty its best not to let the tank run right down anyway - prevents rust and crap at the bottom entering the fuel filter
you are right there!

i would imagine the top of the fuel gauge isn't the actual top of the tank. i've put a fair amount in both my cars and only once has it touched the top of the gauge, and it stayed up there a while!

my old mk3 lied about how much fuel it had after a had to put a new tank in. there i was trundling to the petrol station just about in the reserve and she conked out! doh! :lol:
Gareth_GT_Hatch
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Post by Gareth_GT_Hatch »

SpikeyG40 wrote:
SteB wrote:Apparenlty its best not to let the tank run right down anyway - prevents rust and crap at the bottom entering the fuel filter
you are right there!

i would imagine the top of the fuel gauge isn't the actual top of the tank. i've put a fair amount in both my cars and only once has it touched the top of the gauge, and it stayed up there a while!

my old mk3 lied about how much fuel it had after a had to put a new tank in. there i was trundling to the petrol station just about in the reserve and she conked out! doh! :lol:
Someone made a good point at work the other day about that theory:
If the fuel is always pumped out of the tank from the bottom, what difference does having an empty tank make?


Youve got to admit the guy has a point. Water (which is often the biggest contaminant) is more dense than petrol so it will lie on the bottom. Its probably worse if you dont do alot of miles (gives the fuel a long time to separate out)

We had this debate on clubpolo the other day, mk2 gauges are usually a bit mad, in that they only work for the middle half of the tanks capacity, and mk3 ones do indeed stay put until theres half a tank left and then the gauge falls really fast. I can live with the way the mk3 one works, its very accurate at the bottom of the gauge, and i guess it doesnt really matter if its full or as good as exactly how much fuel is in. the one on my derby stops working with 1/4 of a tank left. I left it for ages on the trip back from the polo show, finally decided to stop when it reached about 300 miles (which is good going as its only a 36 litre tank) and i still had a gallon or two left. :o
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SpikeyG40
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Post by SpikeyG40 »

Gareth_GT_Hatch wrote: Someone made a good point at work the other day about that theory:
If the fuel is always pumped out of the tank from the bottom, what difference does having an empty tank make?


Youve got to admit the guy has a point. Water (which is often the biggest contaminant) is more dense than petrol so it will lie on the bottom. Its probably worse if you dont do alot of miles (gives the fuel a long time to separate out)
its a fair point! what you've also got to remember is that i suspect all the s**t moves around as the car moves and mixes with the petrol as it would be sloshing around in the tank.
Mk2Adam
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Post by Mk2Adam »

i think i've worked out my gauge's little quirks now and it's probably the worst quirk possible......i put £20 in the otherday when it was on the red and it did the petrol pump cut out thing meaning it was full...so that means i've got a guage which measures between 20-42 litres leaving me a 20 litre reserve which i'll need balls of steel to actually use??? :roll:
omicron
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Post by omicron »

just do what I used to do on my old fiat (utterly knacked fuel guage, only read anything when you put the indicators on, and then it did, didn't, did, didn't.....).

Assume, for the sake of safety, you're getting 30mpg, and the tank held 8 gallons. Therefore fill up every 250 miles.
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