Petrol

[gezparton]

Hi everyone
Hope you are all keeping safe  
What are everyone doing about the fuel in their cars.
I seem to have a lot of stale fuel due to lack of use.
Any recommendations for re-vitalising the old fuel?
Happy VE Day tomorrow.
Cheers
Gez

[John Mason]

You can either drain it off and save it for part washing etc. Or do what I do and mix it 50/50 with new petrol. Once the engine warms up it vaporises easier so therefor the engine run ok. That is unless you are into racing or other competition stuff.

John Mason

[Tony Betts]

I see this question come up regular.

But I've never had this problem.

I filled up the super sports last September to do a show. Then it was put away before going on holiday.

I started it two weeks ago, it kicked first time. Ran like a new car.

Tony.

[Peter Clayton]

The problem with old fuel is a strange one . It seems to affect some cars/owners more than others . Could it be garaging,compression,damp/condensation in tanks? I was wodering if anyone of our lucky friends with more than one Seven, have some cars that are fine with old fuel and another that needs priming to start. It would be interesting to identify a common factor.

[Pearls not a Singer]

Hi Gez

Petrol is always difficult to identify exactly what you are getting for your money!  The same brand can vary across the country depending on the source refinery. I always pay the extra for a known brand and don't use supermarket fuels in anything with a motor.

I run all my classics on 97 octane which they all seem to like, especially if improved with tetraboost to add tetraethyl lead which also provides protection against ethanol corrosion.

To cope with the current lack of use with my modern (which has a cat and runs on 95 octane), I've added Stabil stabiliser to stop the fuel going off, but this only works with relatively fresh fuel and will not revive fuel once its  old.

In the states high ethanol blends are cheaper at the pump but you lose about 10% on m.p.g.

This is my personal choice based on experience, I have no connection with any of these products

[39Jet]

The composition of petrol varies both regionally and seasonally. In the winter, for example, a more volatile blend is sold.
Presumably some of these blends would be more stable than others.
When unleaded petrol was introduced in NZ it had, rumour had it, a high level of benzene (C6H6) to bring the petrol up to the advertised octane rating. Rubber fuel hoses were dissolved and fires in engine bays were reported, but the fuel companies denied responsibility - as you would expect, benzene being a dangerous carcinogen.
My grandfather, who fought in Palestine in WWI, always referred to petrol as "benzene".

[Derek Sheldon]

I have six prewar vehicles. I use Morrison’s (supermarket) petrol pretty much exclusively. Some of my cars have been known to sit with petrol in them for over a year. I have never (touch wood) had a problem with starting them based on fuel problems.

[Steve kay]

What becomes evident is that what it says on the pump, may not be what goes into the tank. The forum has dealt with this in the past, differences of fuel in different parts of the country. On a personal basis, previously tanks were kept pretty full, just in case Ross Brawn rang up in the middle of the night and wanted me to drive to Spa in the Ruby right away. They are now kept almost empty, petrol put in when needed. This is being careful, having heard a great deal about fuel going off.  Last year a pal was having great problems starting a motor that had been standing for about a year. Spark OK, timing looked right, fuel certainly circulating. After a few minutes my suggestion was; drain the tank, put some new petrol in. This was muttered about as the owner claimed that when he were a lad, any barn find would fire up right away, let alone his treasured vehicle that had stood for barely a year. Tank drained, half a gallon sloshed in, car fires immediately.

[Dave Mann]

Yes this is a strange one, I've found that our RN saloons fitted with 22FZB carburettors fire up no bother no matter how old the petrol (up to 9 months) is whilst my mate's RP with a 26Va carburettor won't start on 2 month old petrol, I empty the float chamber and fill it with new petrol and it fires up and runs OK.

[Alan]

I find if you leave fuel in the float chamber, after a couple of weeks starting is difficult. If you turn the tap off and let it run dry, then starting next time is ok b