Shelf life of fuel
Discussion
Having not used my fantastic TVR Cerbera for a few weeks, I decided to go for a drive in it last night.
Nice and quiet on the road, windows down so I could hear the engine note cutting through the trees, all was well until a misfire started upon acceleration.
Having owned the car for 7 years, it’ll be the first time I’ve had issues with the AJP8.
I drove for 10 miles or so with the Misfire, which was only upon hard throttle application, I stopped for fuel, £50 of V power and back on the road.
Now the car was back to full power and no misfire.
Is modern fuel that bad, or maybe hot weather destroying the fuel very quickly? It is the old E5 I use, never experienced this before and I’ve in the past left the car for weeks.
Nice and quiet on the road, windows down so I could hear the engine note cutting through the trees, all was well until a misfire started upon acceleration.
Having owned the car for 7 years, it’ll be the first time I’ve had issues with the AJP8.
I drove for 10 miles or so with the Misfire, which was only upon hard throttle application, I stopped for fuel, £50 of V power and back on the road.
Now the car was back to full power and no misfire.
Is modern fuel that bad, or maybe hot weather destroying the fuel very quickly? It is the old E5 I use, never experienced this before and I’ve in the past left the car for weeks.
I have experienced the same . If you can rule out that the ignition system is too damp then the petrol could well be the problem !
I dont use my old Saab as much as I would like but it does pink just like you have described and it is kept in a warm garage .
I guess that it does not matter about the outside conditions petrol will degenerate in any situation over time
I dont use my old Saab as much as I would like but it does pink just like you have described and it is kept in a warm garage .
I guess that it does not matter about the outside conditions petrol will degenerate in any situation over time
MADNESS said:
Having not used my fantastic TVR Cerbera for a few weeks, I decided to go for a drive in it last night.
Nice and quiet on the road, windows down so I could hear the engine note cutting through the trees, all was well until a misfire started upon acceleration.
Having owned the car for 7 years, it’ll be the first time I’ve had issues with the AJP8.
I drove for 10 miles or so with the Misfire, which was only upon hard throttle application, I stopped for fuel, £50 of V power and back on the road.
Now the car was back to full power and no misfire.
Is modern fuel that bad, or maybe hot weather destroying the fuel very quickly? It is the old E5 I use, never experienced this before and I’ve in the past left the car for weeks.
Two recent experiences that make me think it's not the fuel and that there are myths floating about:Nice and quiet on the road, windows down so I could hear the engine note cutting through the trees, all was well until a misfire started upon acceleration.
Having owned the car for 7 years, it’ll be the first time I’ve had issues with the AJP8.
I drove for 10 miles or so with the Misfire, which was only upon hard throttle application, I stopped for fuel, £50 of V power and back on the road.
Now the car was back to full power and no misfire.
Is modern fuel that bad, or maybe hot weather destroying the fuel very quickly? It is the old E5 I use, never experienced this before and I’ve in the past left the car for weeks.
1. My shed that had been stood since October 2021 and not used until May 2022. Reconnected the battery and it fired right up. No misfires when driving or anything (although it had been a bit lumpy before then anyway). Could be that when I had previously filled up it was £1.38 per litre and a better product!!
2. Another shed (an automatic) last week began suddenly misfiring at lower revs. It did this for two days and it has now completely gone.
I also remember the urban myths flying around the internet that the September/October 2021 panic buying frenzy was a deliberate ploy by the government to get everyone to purchase the stale fuel that had accumulated over 18 months of lockdown.
I think climates may potentially play a part. UK climate isn't particularly harsh but it is on the damp side a lot.
I would be minded to think that it could potentially be a bit of moisture accumulating in the fuel tank or in the engine. Or both.
Likewise, engine oil is supposed to break down over time, although how soon and in what circumstances and climates I haven't been affected to investigate. Could be that I'm fluking it.
Advice I've noted online is to mix in some fresh fuel and do an oil change but personally, based on my experiences above (I also fired up a Corolla after six months when I was selling it, and no issues) fuel does not expire that readily.
However, my experience last week leads me to think the spark plugs could do with inspection and probably changing.
Any fuel with ethanol will start attracting water as soon as it’s in an open environment so it depends on how the fuel/car is stored. I have seen cars running on carbs in the US that have had to have the carbs rebuilt after sitting for a couple of months, because the water in the fuel has caused corrosion.
Yes it works, although it's the expensive option.
There's a brand called Sta-Bil offered by our American friends who have suffered the plague of E- petrol longer than us.
I found this stuff out because our inshore LifeBoat started suffering badly from degraded fuel, fouled carbs &c. Things came to a head when she was only capable of 8 knots one night on exercise.
A misfiring, popping, farting engine is not much cop on a LifeBoat, so I did the research and have been using Sta-Bil for some time with very satisfactory results.
I use it in the fuel for my garden machines too, especially for the twostroke engines.
It's cheaper than Fuel Fit and mixes at the rate of 3ml per litre of petrol.
Hope that helps.
There's a brand called Sta-Bil offered by our American friends who have suffered the plague of E- petrol longer than us.
I found this stuff out because our inshore LifeBoat started suffering badly from degraded fuel, fouled carbs &c. Things came to a head when she was only capable of 8 knots one night on exercise.
A misfiring, popping, farting engine is not much cop on a LifeBoat, so I did the research and have been using Sta-Bil for some time with very satisfactory results.
I use it in the fuel for my garden machines too, especially for the twostroke engines.
It's cheaper than Fuel Fit and mixes at the rate of 3ml per litre of petrol.
Hope that helps.
Petrol does “go off” over time if just left idle.
I’ll give you two examples. My Merc’ R129 with half a tank of petrol was on SORN from October 2019 to May 2021, thanks to Covid. During that time I gave it a couple of shots of Wynns Fuel Stabiliser, started it up and ran up and down our little close every three months or so. Come 2021 it ran perfectly.
We also have a 205GTI that’s never used, fuel in the tank was probably over FIVE years old. Then came the time to get it up and running, no chance. The “fuel” in the tank was dead, didn’t even smell like petrol, just liquid gluey stuff. The tank, injectors and the fuel system had to be cleaned.
I’ll give you two examples. My Merc’ R129 with half a tank of petrol was on SORN from October 2019 to May 2021, thanks to Covid. During that time I gave it a couple of shots of Wynns Fuel Stabiliser, started it up and ran up and down our little close every three months or so. Come 2021 it ran perfectly.
We also have a 205GTI that’s never used, fuel in the tank was probably over FIVE years old. Then came the time to get it up and running, no chance. The “fuel” in the tank was dead, didn’t even smell like petrol, just liquid gluey stuff. The tank, injectors and the fuel system had to be cleaned.
Error_404_Username_not_found said:
Yes it works, although it's the expensive option.
There's a brand called Sta-Bil offered by our American friends who have suffered the plague of E- petrol longer than us.
I found this stuff out because our inshore LifeBoat started suffering badly from degraded fuel, fouled carbs &c. Things came to a head when she was only capable of 8 knots one night on exercise.
A misfiring, popping, farting engine is not much cop on a LifeBoat, so I did the research and have been using Sta-Bil for some time with very satisfactory results.
I use it in the fuel for my garden machines too, especially for the twostroke engines.
It's cheaper than Fuel Fit and mixes at the rate of 3ml per litre of petrol.
Hope that helps.
You’re right, it’s a lot cheaper. Amazon are currently wanting £7.45 for enough Fuel Fit to treat 25 litres and £13 for enough Sta-Bil to treat 40 (presumably US) Gallons. Think I’ll be buying that once my current stock of Fuel Fit runs out There's a brand called Sta-Bil offered by our American friends who have suffered the plague of E- petrol longer than us.
I found this stuff out because our inshore LifeBoat started suffering badly from degraded fuel, fouled carbs &c. Things came to a head when she was only capable of 8 knots one night on exercise.
A misfiring, popping, farting engine is not much cop on a LifeBoat, so I did the research and have been using Sta-Bil for some time with very satisfactory results.
I use it in the fuel for my garden machines too, especially for the twostroke engines.
It's cheaper than Fuel Fit and mixes at the rate of 3ml per litre of petrol.
Hope that helps.
alangla said:
Error_404_Username_not_found said:
Yes it works, although it's the expensive option.
There's a brand called Sta-Bil offered by our American friends who have suffered the plague of E- petrol longer than us.
I found this stuff out because our inshore LifeBoat started suffering badly from degraded fuel, fouled carbs &c. Things came to a head when she was only capable of 8 knots one night on exercise.
A misfiring, popping, farting engine is not much cop on a LifeBoat, so I did the research and have been using Sta-Bil for some time with very satisfactory results.
I use it in the fuel for my garden machines too, especially for the twostroke engines.
It's cheaper than Fuel Fit and mixes at the rate of 3ml per litre of petrol.
Hope that helps.
You’re right, it’s a lot cheaper. Amazon are currently wanting £7.45 for enough Fuel Fit to treat 25 litres and £13 for enough Sta-Bil to treat 40 (presumably US) Gallons. Think I’ll be buying that once my current stock of Fuel Fit runs out There's a brand called Sta-Bil offered by our American friends who have suffered the plague of E- petrol longer than us.
I found this stuff out because our inshore LifeBoat started suffering badly from degraded fuel, fouled carbs &c. Things came to a head when she was only capable of 8 knots one night on exercise.
A misfiring, popping, farting engine is not much cop on a LifeBoat, so I did the research and have been using Sta-Bil for some time with very satisfactory results.
I use it in the fuel for my garden machines too, especially for the twostroke engines.
It's cheaper than Fuel Fit and mixes at the rate of 3ml per litre of petrol.
Hope that helps.
Worth shopping around for sure. I paid £61 last time I bought it and that was a bargain compared with the cost of Fuel Fit.
And my experience is that it is effective FWIW. Plus I found Fuel Fit a bit smoky, but that was in a twostroke outboard to be fair.
MADNESS said:
Having not used my fantastic TVR Cerbera for a few weeks, I decided to go for a drive in it last night.
Nice and quiet on the road, windows down so I could hear the engine note cutting through the trees, all was well until a misfire started upon acceleration.
Having owned the car for 7 years, it’ll be the first time I’ve had issues with the AJP8.
I drove for 10 miles or so with the Misfire, which was only upon hard throttle application, I stopped for fuel, £50 of V power and back on the road.
Now the car was back to full power and no misfire.
Is modern fuel that bad, or maybe hot weather destroying the fuel very quickly? It is the old E5 I use, never experienced this before and I’ve in the past left the car for weeks.
If it was parked outside all that time then Tivs happily vent out the volatiles and over a few weeks and in this weather it's entirely plausible that was your issue. The MBU ECU isn't exactly smart and the engine is specifically set for higher octane levels so where a modern, mass produced car will probably adapt to petrol missing some volatiles the Tiv isn't going to. Nice and quiet on the road, windows down so I could hear the engine note cutting through the trees, all was well until a misfire started upon acceleration.
Having owned the car for 7 years, it’ll be the first time I’ve had issues with the AJP8.
I drove for 10 miles or so with the Misfire, which was only upon hard throttle application, I stopped for fuel, £50 of V power and back on the road.
Now the car was back to full power and no misfire.
Is modern fuel that bad, or maybe hot weather destroying the fuel very quickly? It is the old E5 I use, never experienced this before and I’ve in the past left the car for weeks.
Mr Tidy said:
If it helps anyone Esso Synergy Supreme is 99 RON and in most parts of the UK it is E0 - even though the pumps have to be labelled E5.

Devon and Cornwall and parts of the North excluded.
Luckily here in the middle of the country, it's all good.
Expensive though, £1.91 a litre.
rigga said:
Mr Tidy said:
If it helps anyone Esso Synergy Supreme is 99 RON and in most parts of the UK it is E0 - even though the pumps have to be labelled E5.

Devon and Cornwall and parts of the North excluded.
Luckily here in the middle of the country, it's all good.
Mr Tidy said:
If it helps anyone Esso Synergy Supreme is 99 RON and in most parts of the UK it is E0 - even though the pumps have to be labelled E5.
Is this definitely still the case?I remember seeing a random video a few years ago from someone (possibly a tuner) testing it for ethanol content but it strikes me as something that could change at any moment without anyone realising.
I never really buy the fuel argument. My motorbike was off the road for a period of time (years!) while I was away, based on when it was last MOT'd the fuel could easily be 5 years old and it started up almost right away and behaved normally, straight from the garage 10 miles to the MOT centre and back again.
Condi said:
I never really buy the fuel argument. My motorbike was off the road for a period of time (years!) while I was away, based on when it was last MOT'd the fuel could easily be 5 years old and it started up almost right away and behaved normally, straight from the garage 10 miles to the MOT centre and back again.
Yup. There is bucket loads of magic beans and snake oil involved in this. But there are some exceptions. Your typical modern vehicle vents it's tank properly and that tank is generally located on the vehicle in a position where it isn't unnecessarily heated. Those vehicles have also been tested in hot conditions and use ECUs capable of adjusting to global fuel qualities.
Something like a TVR is almost the polar opposite.
. The venting system is closer to the Victorian era than 21st century. The fuel tank will bake in the sun so the diurnal cycles will not just happily off gas the volatiles but the tank will also sweat like a fat lass gorging on the third kebab. The tank also gets heated by the exhaust so when it is used you're warming up the petrol as well. The standard ECU is as thick as mince so struggles to compensate for fuel variations and the AJP engine is more highly strung than say a Japanese sports bike motor, or maybe the better phrase is 'more emotional'. Cap that with typical usage not being daily and while I really don't buy into all the fuel panicking being done by people with conventional cars, your typical TVR set up and usage does put it at risk and owners of such cars need to apply some common sense to mitigate that risk that owners of normal cars just don't have to worry about. As for those American tales of crusty carbs. They've had more than enough years of ethanol use to learn how to do the really simple preemptive things to use ethanol fuel very happily and for it to never be a problem but some drivers just can't be bothered. Crusty carbs is a choice like eating two pies for breakfast. Drinking Diet Coke, like fuel stabilisers, is not the solution but simply a fat person's way of spending money to avoid reality.
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