Storing over winter and fuel in the tank

[PRO5T]

What's the common consensus these days with modern fuel in a relatively modern classic (in this case a 2003 996.2 911 GT3)? I may take it off the road a little early this year as I'm itching to do some restorative work but by the time I do that it'll be about time for it to come off the winter roads.

I mostly use Shell V Power and my habit has always been to put it away fully brimmed-any odd salt free bright days I can still pull out and take for a blast.

Is it just wasting a full tank as it'll deteriorate over the four or five months or will leaving a quarter of a tank mean more air in there to turn things sour?

For what it's worth, the engine is very highly tuned and it's not recommended to run anything less than high octane fuel-so if I'm left with a duff tank I'd need to burn all that out or worse, syphon out and dispose.

[Gulf7]

I brim my Caterham Seven's tank over winter hibernation.

It used to be that Esso Synergy Supreme+ 99 was E0, but even that's E5 now. I still think brimming it is the best option though to minimise the chance of corrosion.

[SAS Tom]

The fuel will be fine, wouldn’t worry about it. I filled up my 35 year old motorbike several months ago and it’ll have no issue firing up now or even in 6 months time when I’m likely to use it again.

[richhead]

If it has a metal fuel tank then brim it, I mean really brim it, ideally top up after parking.if not, just park it with whatever is in it.

[Baldchap]

BP did testing and found in a sealed container, fuel did not appreciably deteriorate. A fuel tank on anything remotely modern is essentially sealed.

Carbs (where fitted) gumming are an issue more than fuel in tanks.

Basically don't worry about it.

[zsdom]

If its got an in tank pump make sure it stays wet, I stored my car with the fuel light on, the pump seized & I had to drop the tank & replace thw pump

[Missy Charm]

As a result of coronavirus I didn't touch my car for about six months. It stayed parked in the drive exactly as it had been left, battery connected and whatever petrol was left from the last drive sitting in the tank. Restrictions were then lifted and it became necessary to start driving again. I'm pleased to say that the only appreciable effect from the six month sit was that the car was a bit sluggish to turn over the first time. It then started, ran and has continued to run ever since.

Mine's a couple of years younger than the OP's.

[rallycross]

Should be fine for up to 5 years
Find something better to worry about!

[LuS1fer]

Mine sits in my Mustang for 6 months, without any issues at all, whether low or high fuel.

I've had the car nearly 20 years. A few years back, I replaced the fuel pump and the tank within was as shiny as a 10p piece with no rust at all.

[Mr Tidy]

Brimming it seems to be the best idea, and the good stuff has less Ethanol in it so is less likely to cause problems later.

Now you just need some will-power to avoid wanting to use it if we get another sunny day!

[Heaveho]

My Evo and Mk1 MR2 have sat for 3 years with a third of a tank of Shell 99 and a smart charger. They were fine. 6 months is nothing.

[Alex_225]

I actually left my RS Megane for 11 years with a full tank of fuel, the fuel pump was rusted where the fuel separated and now it's stored with a minimal amount of fuel in it. Over the winter, I can't imagine it'll cause you many issues if you plan to get it out in the new year.

[Saleen836]

LuS1fer said:

Mine sits in my Mustang for 6 months, without any issues at all, whether low or high fuel.

I've had the car nearly 20 years. A few years back, I replaced the fuel pump and the tank within was as shiny as a 10p piece with no rust at all.

Snap, mine sits unused for up to 6 months at a time with different levels of fuel left in it, over my ownership (18 years) never had a problem, don't even over inflate the tyres, just park it in my garage attach the battery minder and forget about it 'till the weather improves.

[Old Merc]

If it’s just six winter months don’t worry, I do it every year. My Merc’ SL has just gone SORN with quartet of a tank of super. During Covid when it stayed in the garage for over a year I added some Wynns fuel stabiliser in the tank.

[donkmeister]

Baldchap said:

Carbs (where fitted) gumming are an issue more than fuel in tanks.

Even this seems to be less of an issue these days - I used to add fuel stabiliser and flush out the carb on my lawnmower with carb cleaner, because I found it would gum up over winter if I didn't. But, the last few years I didn't bother and have found that the very same carb doesn't get gummed up anymore.

Yes that's anecdotal but I saw a video by Car Care Nut on vehicle winterisation recently where he explained the gumming/varnishing used to happen because of additives to stop fuel evaporation in the carb, which are no longer used as carbs are so rare now.