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how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 1:26 am
by //no.comment
hey,

due to the petrol gauge not working i think i currently have about 20miles of petrol left!

i was wondering how far people are getting on just a tank of petrol, so i can be a little more accurate
i have no idea how big the tank is or how many MPG im getting, and i think my 200miles a tank assumption is a bit off!

I was filling my tank up last week from a state that was supposedly fairly empty, but i was very happy when the pump clicked off at just over a tenner! woooohoooo more petrol than i thought! how should i adjust my calculations?

most of my driving is round manchester too-ing and fro-ing but occasionly a few burn ups into the countryside to go climbing.

So someone give me a better assumption and ill carry that spare can of petrol ;)

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 8:07 am
by autolycus
Hardly rocket science, is it?

Fill your tank up, making sure it really is full, not just the pump cutting out at the first splash-back ("brim it").

Drive, say, 100 - 150 miles.

Brim it again, this time noting exactly how much fuel it takes - in litres, not £.

Convert this to gallons, by dividing by 4.54. You may use a calculator.

Divide the number of miles you drove by the number of gallons you used. If you needed a calculator for the last step, you certainly will for this one. This will tell you your average consumption in mpg. Don't round any of the numbers to worse than one decimal place before you get to your final answer.

Refinements: Find out your tank capacity (left to the OP's ingenuity). Check your odometer against the km posts on a motorway over, say, 5 miles (8km). The approximation of 1mile = 1.6km is close enough for this purpose.

Kevin

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 8:20 am
by MarkyB
If you don't want to do a lot of calculations carry a filled petrol can.
Also you can use a wooden dowel as a dip stick.

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 8:34 am
by LouiseM
Wouldn't it be better to simply fix the fuel guage problem? :-?

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 8:42 am
by alex_holden
You should be able to get over 250 miles from a tank on a long run. I think my record is about 280. Lots of short runs around town and you might only get 150-200 miles.

The standard tank capacity for a late car is 6.5 gallons (just under 30 litres), BTW.

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 9:59 am
by chickenjohn
alex_holden wrote:You should be able to get over 250 miles from a tank on a long run. I think my record is about 280. Lots of short runs around town and you might only get 150-200 miles.

The standard tank capacity for a late car is 6.5 gallons (just under 30 litres), BTW.
I concurr with Alex. 250+ on a long run. Provided, of course the Minor is in good mechanical order and the driver drives sensibly and economically.

On the club holidays, I got all the way from Thanet to the Isle of wight, then after all the touring on the island, only had to fill up on the way back.

I did use to have a Minor with a non-functioning petrol gauge, best thing to do is mend it!!!

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 11:56 am
by mike.perry
The dipstick works on a car but you can't get it past the bend in the filler pipe on a traveller. Fixing the fuel gauge depends on identifying the fault, tank sender, voltage stabiliser, fuel gauge etc.
I reckon on 30 - 35 mpg mixed driving, which does not help much when fuel is sold in litres (and priced in gold bars).

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 1:41 pm
by //no.comment
ok i did do the MPG work out and i got 32mpg calling it 200 on the cautious side,
i think the difference between my estimation and how much fuel i actually had was due to only half filling it up several times and the compound error eventually meant i had more fuel than first thought!
Ive tried earthing the fuel gauge and i get FSD so that must be working, next im going to try removing the sender but i need to wait untill i get rid of this full tank!in the mean time i may try running a temp wire between the sender and the gauge to rule out any shorts to earth affecting the reading.
how can i test the voltage stabilser?
but in the mean time ill use a dip stick!

thanks
Andrew

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 3:33 pm
by chickenjohn
You should be getting better than 32MPG, in a standard Minor.

Or was this for stop- start commuting??

I used to get an average of 39MPG mixed commuting and motorway and 44-45mpg on long runs.

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 6:09 pm
by //no.comment
im at uni so i dont really commute, more going to sainsburys! so lots of short trips weighed down with 4 hefty lads and alot of whiskey!
also a reason for the poor MPG is that the vac advance is running a bit poorly, the rubber has perished and i cant find any moggy suppliers with them in stock! at the moment its taped up which seems to be doing the job ok-ish.
just another job i need to get round to doing, truoble is im right in the middle of my third year exams!

thanks for all the help.
Andrew

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 7:04 pm
by PSL184
Any bit of tubing will do to secure your vac pipe - Go down to the science / mechanical dept at uni and borrow some hydraulic tubing :lol:

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 11:05 pm
by chickenjohn
Maybe he means the actual rubber diaphragm in the vacuum advance unit, itself. These can fail after a while (say 40 years!)

Re: how far should i get on a tank of petrol?

Posted: Fri May 14, 2010 11:19 pm
by bmcecosse
Good luck with the exams! I still wake up with nightmares about third year exams , 40+ years after the event! Strangely - I had no real problems with final year exams.