View Full Version : How long can you keep petrol ?

23-01-2006, 06:44 AM
Looking for advice again - how long is it Ok to keep petrol in your tanks before throwing it out ?

23-01-2006, 07:59 AM
G'day CF & FF,

there has been quite a bit of discussion on this topic over the past couple of months...hit the search function and i'm sure you'll turn up some helpful info.

For me I'm happy to hold fuel for 3 months before burning it off in the car and starting again...others 2-6 weeks.

Two years ago I left a tank of shell optimax in the Harly parked up for 9 months and came back to a carby full of green jelly and a tank full of green liquid that smelled like kero...first time I'd ever had fuel go off. (I was in a company vehicle)

Last year it sat around for 6 mths with premium and was fine...so I reckon 3 mths to be safe IMO

Others will have other opinions...see recent discussion on Premium v Standard unleaded

Happy searching


23-01-2006, 08:06 AM
2 - 3 months. On the shorter side if you have oil mixed in or if the tank is vented to the atmosphere or partly filled. You can still use it if its a bit stale if you dilute it with 2 parts fresh fuel. You have to use it straight away though or the old fuel will act as a catalyst and you will have even more stale fuel. You can buy octane booster additive which will help too.

There are fuel preservers which will preserve the fuel (and oil if premix) for up to one year. They are also handy of you are not going to use your motor for long period as you don't have to drain the carby and fuel system.

23-01-2006, 02:13 PM
A few tips.. If you want to store the fuel longer than say 8 weeks. Make sure the tank is full. This will minimise air and reduce the likleyhood of moisture. Alternatively have it near empty and add Petrol Power at 25ml per 100l (Whitworths). Make sure it has been run with the mixture so the carbs also contain the fuel stabiliser. When you finally use it, fill the rest of the tank with fresh fuel.