Stale petrol

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engineer
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Stale petrol

Post by engineer »

The RAC & others would have us believe that petrol deteriorates appreciably after few months. My car has 10 year old petrol in the tank. It starts but only after turning the engine over for a long while. It is said that the old petrol becomes more dense, less volatile, less calorific and might phase separate the aqueus part. I imagined that warming the fuel could in part correct the density & volatility, so I warmed up the fuel immediately before the jet. Starting was dramatically improved, when tested on two recent cold mornings. Has anyone any information on the subject?
les
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Re: Stale petrol

Post by les »

Maybe petrol was better 10years ago. :D Mind you if you have to warm it up to get a reasonable start up, probably the RAC and others are right !

philthehill
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Re: Stale petrol

Post by philthehill »

Petrol years ago did not seem to absorb the moisture like it does now.
I would not even consider the retention or use of 10 year old petrol even in my old mower.
Get rid of and buy some fresh petrol.

les
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Re: Stale petrol

Post by les »

Wish my petrol lasted 10 years, I have to fill up every other week!!

myoldjalopy
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Re: Stale petrol

Post by myoldjalopy »

Regards the query, you would think that as a car needs choke until warmed up, warming the fuel will also have a beneficial effect on starting as it makes the fuel more volatile.
Murrayminor
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Re: Stale petrol

Post by Murrayminor »

I had to clean the fuel system on my old mini 1275GT which was fitted with twin tanks, I cannot forget the horrible smell of stale fuel, nor the gunk it left behind.
Get rid of the stale fuel and treat your car to some fresh stuff, it will repay you in the long run.
Proud owner of my first Morris Minor
pgp001
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Re: Stale petrol

Post by pgp001 »

As well as my Traveller I have a couple of old motorbikes, one is a 1972 Honda XL250 Motosport that gets used most years (not this one so far though)
The other bike is 1950 BSA 350 Gold Star which hardly ever goes out, the last new fuel went in the tank in August 2013.

I always start it up and let it get up to temperature at least once a year, and in the 38 years I have owned it the bike has never failed to start on the second or third kick despite the old fuel.
I was starting to think the petrol may be past its best, so keep draining a bit from the tank and use it when I need to wash some oily Morris bits or clean some paintbrushes.
I wonder if the next tank full will last seven years :D

Phil P
gtt1951
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Re: Stale petrol

Post by gtt1951 »

When I sold my first 1964 2-door saloon to a local dustman, it had been standing for about 6 years (since 1984) with a partial tank of 3-star petrol.
There were no problems with "real" petrol and it would start on the first quarter turn of the hand-crank (I wasn't going to replace the battery on a car I wasn't using).
I think that the current day problems are due to the use of that rubbish Euro E5 unleaded 95 RON petrol.
In lean times, I used to run that car on 2-star and, when a bit more flush and going for a longer journey, it was treated to 4-star.
The 1098cc engine ran well on all three grades.

George.
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'50 Low-light with 918 Side-valve engine,
'51 High-light with Side-valve 918 engine,
'55 4-dr with 803 engine,
'56 Traveller with 1098 engine.
morris van
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Re: Stale petrol

Post by morris van »

I was given an A35 van in 1996 which had been sitting in a shed since 1980 and all I did was put a battery on it and started first time.

engineer
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Re: Stale petrol

Post by engineer »

les wrote: Thu Nov 26, 2020 5:46 pm Maybe petrol was better 10years ago. :D Mind you if you have to warm it up to get a reasonable start up, probably the RAC and others are right !
Since it will probably be warmer weather before I drive anywhere, I might just see how it goes then.
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