Stale Petrol

[Car-Nut]

Anyone know of or used these

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0267371682

[christopher storey]

I imagine snake oil is just as effective . If its any comfort to you, I have never had to change/drain fuel after a layup, and there is no such thing as waxing of petrol - diesel yes ( in cold temps) and paraffin as used in jet fuel ( in very cold temperatures ) - but petrol , no . There can be a problem in humid climates with fungus growth and sometimes with a resinous deposit ( varnish) but as I say in decades of laying up cars, I have never had any trouble . As you will know from your recent filter change, a far greater hazard is all the foreign bodies which get into tanks!

[JEP41]

I agree with Christopher, I owned a V12 E-Type back in the 1970's and for four years while living in Houston Texas the car sat in the Garage back in England. It was pulled out MOT'd and driven only once a year during the annual trip home for a month and never gave any stale petrol problems. :)

[Moeregaard]

This is a big problem in the States, especially in California where a number of strange additives are mandated for pollution control. Fuel stabilizers are a good thing for any car laid up for more than a few months. Another option is to top off with aviation petrol (100LL), since the storage requirements are much more stringent and it will retain its stability for up to two years.

[Heuer]

Petrol is refined from heavy crude oil and during the process the molecular structure is changed to produce 'motor spirit'. This mix contains volatile substances which tend to evaporate over time, what's left can oxidise and become contaminated. The lightest fractions evaporate whilst the remains gradually join their molecules back into heavier stuff they were once cracked from. This is the "gum" that befouls so many lawn mowers that have been unused for a period of time. In sealed containers none of these should happen and shelf life will be years. In a vented car fuel system all are possible. Unleaded petrol contains more aromatics than leaded to boost the octane. These are more prone to oxidation and gumming than the normal straight chain components, and are also more aggressive solvents to rubbers and gasket materials in old cars. So called "stabilisers" are probably anti oxidants.

Old, unused, petrol does indeed go 'stale', smells foul, and changes colour - when its more than 3 years old it is a golden colour, will still run but exhaust fumes will smell; more than 10 years it smells of old engine oil and will barely run; more that 25 years it wont come out of the tank as it will be tar.

If you are going to lay up your car for the winter fill the tank as the petrol will provide protection against the tank rusting where it is exposed to air. When you next run the car there may initially be a loss of performance but fresh fuel will sort that. Always worth starting the car once a month and let it run (at 2,500 rpm) until it reaches normal temperature.

[Car-Nut]

If you are going to lay up your car for the winter fill the tank as the petrol will provide protection against the tank rusting where it is exposed to air. When you next run the car there may initially be a loss of performance but fresh fuel will sort that. Always worth starting the car once a month and let it run (at 2,500 rpm) until it reaches normal temperature.

There starts another thread

http://etypeuk.com/forum/viewtopic.php?p=7332#7332