Petrol @shelf life@

Sthurley · 07 January 2019, 17:39

Hello All

Would anybody like to share their views on how long petrol can be stored for before it goes off/bad, causes poor performance?

HDAV · 07 January 2019, 18:20

Pump fresh couple of months, with stabiliser 12+ depends on many factors storage conditions, required octane, ethanol content etc etc

Underground or proper storage tanks it should last long periods, surface vented tanks subject to temp variations and moisture not so long. That said I have not had engine issues with old fuel but lots of people seem too..... for what it costs add some stabiliser you might not need it....

Poly · 07 January 2019, 18:28

Quote:

Originally Posted by Sthurley

Hello All

Would anybody like to share their views on how long petrol can be stored for before it goes off/bad, causes poor performance?

It depends.

In plastic can, sealed, with no moisture and minimal air gap for condensation I’ve used two year old fuel with no noticeable issues.

With two stroke oil premixed some people claim weeks rather than months is all it takes for issues to start!

Many people suggest the issue is exacerbated with modern fuel that contains bio ethanol. I’ve never noticed an issue in the UK - other countries may add more ethanol or have different storage regimes that make issues more likely.

Bremar · 07 January 2019, 19:52

Minor thread drift. Are people storing their ribs with a full fixed fuel tank or are you running it down to low'ish then just adding fresh fuel at beginning of season. Mine is on the driveway with low fuel (about 5-7 litres) in the 40 litre fixed aluminium fuel tank ready for top up at the start of next season (so that will be 6 months in storage)?

HDAV · 07 January 2019, 19:59

Quote:

Originally Posted by Bremar

Minor thread drift. Are people storing their ribs with a full fixed fuel tank or are you running it down to low'ish then just adding fresh fuel at beginning of season. Mine is on the driveway with low fuel (about 5-7 litres) in the 40 litre fixed aluminium fuel tank ready for top up at the start of next season (so that will be 6 months in storage)?

Lots of room in that tank for moist air to enter via vent and condense inside, a full tank of stabilised fuel that won’t happen...... but then a decent separator will remove the water, and you will have mostly fresh fuel and some stale old fuel....

Personally I try and store the tank full with stabilised fuel... right now I have a half a tank of stabilised fuel, after an impromptu Xmas run out..... not sure whether to top it off and add more stabiliser or leave it....

smallribber · 08 January 2019, 07:02

I think this is a subject that is exaggerated and blamed for several engine issues wrongly.

Only last week I went and started a Toyota Previa which had stood for over 1.5 years with petrol in the tank. I put on a fresh battery and off she went no issues at all. There was another thread on here recently that suggested more like a 6 year lay up on a similar car.

HDAV · 08 January 2019, 08:12

Interesting fact sheet

https://www.bp.com/content/dam/bp-co...icle-tanks.pdf

pagick · 08 January 2019, 17:46

Here is what I do but not the definitive answer.
Here in the US we have 10% ethanol in our gas. Because some politician wanted votes from the corn farmers.
The gas goes bad faster I am told by several sources as well as the internet, so it must be true, that 3 months is max recommended storage. It gets gummy at the bottom of the tank they say.
Anyway I store about 30 gal of fuel on the side of my home in Nato metal cans. Because I live in earthquake prone region. I put stabilizer in the cans that are full. Every 6 months I rotate the gas out and replace.
During the summer I use it in my boat as well as my work generator year around. Never had a problem but I never pushed it.
My new Evenrude Etec 60hp has the in-engine fuel winterized full with "Star-Tron" brand stabilizer. And I bet Evenrude tested the different brands for the ethanol gas problem.
Now my 1980's Mercury 90hp would never start after winter with or without fuel in the carb. So some engines are more buggy about sitting and old fuel.
P.S. Do you guys have Ethanol in your petrol?

HDAV · 08 January 2019, 18:15

Yes we have 5-7% ethanol content currently I think but due to increase soon

https://www.esso.co.uk/fuels-faqs

Quote:

The majority of unleaded 95 Octane petrol sold in the UK contains up to 5% ethanol as required under the Government’s Renewable Transport Fuels Obligation (RTFO).

There is currently no requirement for renewable fuel (such as ethanol) to be present in super unleaded (97 grade petrol).

Didn’t know that super was ethanol free though.... interesting

Poly · 08 January 2019, 18:47

Quote:

Originally Posted by HDAV

Didn’t know that super was ethanol free though.... interesting

Read it carefully again. They don’t require to put ethanol in it - that doesn’t mean that they haven’t!

chipko · 08 January 2019, 18:54

Not what they say further in, unless you’re one of the poor feckers up North or south west!

“Esso super unleaded petrol (Synergy Supreme+ Unleaded 97) is ethanol free (except in Devon, Cornwall, the Teesside area and Scotland). We would therefore advise anyone who has concerns about the presence of ethanol in petrol to use Synergy Supreme+ – providing they do not fill up in Devon or Cornwall, the Teesside area or Scotland.”

smallribber · 08 January 2019, 20:51

I think the OP wanted real world examples rather than all this theory Spouting

willk · 08 January 2019, 21:18

Quote:

Originally Posted by Bigplumbs

I think the OP wanted real world examples rather than all this theory Spouting

How rude!

Xk59D · 08 January 2019, 21:26

Quote:

Originally Posted by willk

How rude!

He should probably get a bit of humility

beamishken · 08 January 2019, 21:59

The linked document is almost 10 years old how accurate is it today? Id imagine quite a bit has changed since that document was published .
Im sure I read recently that the condensation in fuel tanks theory had been disproved.

Dan Gurney · 08 January 2019, 22:18

Quote:

Originally Posted by Bigplumbs

I think the OP wanted real world examples rather than all this theory Spouting

Quote:

Originally Posted by Sthurley

share their views

Pedantic I know plummy me old son, but he (she?) appears to be asking for "views".

Dangerous business on Ribnet obvs...

willk · 08 January 2019, 22:44

Quote:

Originally Posted by beamishken

Im sure I read recently that the condensation in fuel tanks theory had been disproved.

Despite the risk of being accused of Spouting, I have some Empirical Evidence to support your reading. I've maintained fuel tanks in the wettest, most humid corner of Ireland for the past 30 years and I have yet to trap a single drop of water in a filter. I believe that temperature range and original source have the biggest part to play in "water in tank" attributed to "condensation".

That said, I had an interesting (to me) conversation with a tool-hire guy recently - he said that he was seeing a lot of corrosion in over-wintered carbs that he was blaming on residual water from ethanol rich petrol. Do your own math, E&OE, YMMV.

lakelandterrier · 08 January 2019, 22:49

I know there is a lot of theoretic chemistry stuff...all great and technical I'm sure.

In reality, for many years I've wintered my boat for 6-7 months with a 1/3 to 1/2 full tank of "normal" unleaded petrol. Filled up to top at start of season - never a problem.

Had a 4 HP with external tank I didn't use for over 2 years...that fuel went "off". Obvious to see when I tipped some into a jar.

Does that help the OP?

jeffstevens763@g · 08 January 2019, 23:33

Quote:

Originally Posted by lakelandterrier

I know there is a lot of theoretic chemistry stuff...all great and technical I'm sure.

In reality, for many years I've wintered my boat for 6-7 months with a 1/3 to 1/2 full tank of "normal" unleaded petrol. Filled up to top at start of season - never a problem.

Had a 4 HP with external tank I didn't use for over 2 years...that fuel went "off". Obvious to see when I tipped some into a jar.

Does that help the OP?

+1 I do stabilise for long periods but didn't have an issue before I did but fuel did go off in the aux motor

HDAV · 09 January 2019, 01:05

Quote:

Originally Posted by Poly

Read it carefully again. They don’t require to put ethanol in it - that doesn’t mean that they haven’t!

Quite right as it seems in Devon, Cornwall, Teeside and Scotland they have....... odd choice of locations for added ethanol......

As for none theoretical anecdotes........ I have not yet suffered a fuel quality failures/issues with 2 or 4 stroke equipment since I started looking after the fuel and fuel mixing..... that everything from stihl 28cc garden stuff up to 200bhp plus marine engines.