Life of petrol in car

Shelle

Does anyone here know if there is a "lifetime" for petrol in a tank of a car that has not been used?  Basically, due to being hospitalised in an emergency and then not being discharged for 3  months, my car was left in my garage at home unused.  I submitted a SORN on it in the first month.  Despite being discharged at the beginning of February, I am currently still unable to drive and need further physio.  Please note I am not medically unfit to drive, I have imposed it on myself due to not being able to lift my foot off the accelerator pedal to the brake easily which I decided was too dangerous.  Thus, fast forward to today my car has not been used for coming up to a year.  I am now wondering, aside from the battery possibly being flat (I should point out, although not sure if relevant, that the car was brand new and I had only had it for 6 weeks before I ended up in hospital), whether the petrol in the tank will be ok?  I dont know at this point how much is in there as I havent switched on the engine yet, but am now worried in case the petrol could damage the engine if I switch it on?  And what about the tyres?  Should I call out an engineer to look at it before bringing it out of the garage?  (I have a drive so could be done on private property until I renew tax once I can drive)  Any thoughts?  Or suggestions who to ask if this is not the right place?  Many thanks and hope I have made sense.

facade

You read all sorts of stuff on the internet about petrol "going off" when it is stored, and they are all different.

Most likely after 12 months it will be a little harder to start the car and it might not run as well.

What I would do is just add a gallon of decent 99 octane to the tank, something like Shell V-power or Esso Synergy Supreme, so it can mix in and "freshen up" the fuel. Then once it is running again, keep using the V-power for a couple of tankfuls to let the detergent additives clean out any deposits from the stale fuel.

The tyres should just need topping up to pressure unless they were completely flat with the weight of the car on themand the side walls cracked.

Your biggest problem is that the battery is probably dead from being allowed to go flat and remain flat for weeks, but you may be lucky, and there is enough left in it that it can be charged.

If you left the handbrake on, and parked it up when it was damp the rear brakes might be stuck, but rocking the car backwards & forwards should unstick them.

The brake discs will probably have some surface rust, so go easy on the brakes for a few miles and they should clean up.

There might be a bit of wobbling from flats in the tyres initially, but it will disappear after a few miles as the rubber flexes.

12 months in a dry garage shouldn't cause any significant problem, but if it re-assures you,  by all means get someone to check it over, it ought to be serviced as soon as it is running anyway.

KXL88

Firstly hope every new day is an improvement and one day closer to getting back in your car. You probably need a battery jump start and depending on how much fuel is in the car, start the car and leave it a min to let the oils circulate first, and visit the closest petrol station and put their finest petrol (97-99Ron) and take a long ish drive to charge up the battery. Does petrol have a lifespan, I know it gets a bit stale but let it mix with new petrol. Else if tank is near full, if you are really worried, get one of those misfuelling services to drain your tank. 

CliveOfIndia

Petrol does go "off" over time, but in my experience the effect it has can vary.  I had my car off the road for about 14 months or so during Covid, all I did was kept the battery topped up every so often with a trickle charger.  When the time came to get it back on the road, it fired up straight away and has been running fine ever since.

My lawnmower and the outboard for my boat are the opposite - after a winter in the garage, they're a real pig to start if I use the old petrol from the jerry-can.  Stick in some fresh petrol and no problem at all.  What I then tend to do is mix the old stuff with new petrol, roughly 50/50 or so, just so as not to waste it, and it always seems to work just fine.

I would say just give it a go and see what happens.  You may find it runs a tiny bit lumpy, it may very well not make any noticeable difference at all.  Either way, after a couple of tanks of fresh fuel it'll be fine.

Shelle

Thanks everyone.  It has been worrying me for a while especially as I couldnt do anything about it for so long.  I will certainly take your suggestions on board.  At least we know it shouldnt be too difficult to sort out, so just looking forward to being able to get back in and drive to anywhere I like instead of 2 and 3 buses getting delayed or cancelled left right and centre!  Hope I can remember how to drive it seeing as it was brand new and an automatic for the first time LOL  Thanks again, much appreciated

LunaLater

Remember to check your tyre pressures.

sk2402005

If the car has been off the road for that long, if you get it going, its probably prudent to take if for an MOT, as any number of things could have failed.

Shelle

sk2402005 said:

If the car has been off the road for that long, if you get it going, its probably prudent to take if for an MOT, as any number of things could have failed.

Can you even do a MOT when the car is only a year old?

ElefantEd

Shelle said:

sk2402005 said:

If the car has been off the road for that long, if you get it going, its probably prudent to take if for an MOT, as any number of things could have failed.

Can you even do a MOT when the car is only a year old?

A check up by a decent mechanic (functionally the same, but without the piece of paper) is an obvious alternative.

Shelle

I will certainly get it checked over once I get it started/charged up etc for peace of mind.

rollingmoon

I've had unleaded go off in a lot less than 12 months... rank fuel is easily detected as it has a horrible, almost sweet, smell that's quite distinct to the normal odour of petrol. If there's only a bit in then brimming the tank with fresh stuff will usually do the trick, but if it's full and you can't get it to start you'll need to get it drained out.