This might seem like an odd question, but does diesel go off? Stupidly, I filled my CR-V with diesel just before the lockdown was introduced and the car has been off the road ever since. By the time the lockdown has been lifted, it could be three or four months of inactivity for the car.
My wife says it will be fine, but I’m sure I remember you saying something about shelf life and not storing diesel for a long period of time.
Please let me know – there’s no rush!
You have a good memory. I’ve searched my records, but I can’t find a response about fuel, which suggests it stems from the days when I was using a quill.
It’s not an odd question. Given the price of oil, I’m tempted to buy an old tanker and store a load of diesel in the garden. Sadly, I don’t think my wife would be too keen on the idea.
Anyway, I understand your concerns about the 58 litres of diesel sitting in your Honda’s tank, not least because you would have filled up before the prices plummeted. There’s no need to worry just yet. Diesel can sit in the tank for up to a year without a problem, so it’s not going to go off. Petrol has a shorter shelf life of up to six months.
After a year, the diesel has the potential to clog filters and cause damage to the engine, so I definitely wouldn’t recommend using it then. In the meantime, I’d suggest running the car for about 20 minutes every fortnight, just to keep the battery topped up and the engine working. I’d also suggest moving the car a few inches, but I’d refer you to my response to Max, which I’ll attach to this email to save you waiting for the magazine.
As an aside, did you know that it’s illegal to store more than 30 litres of petrol at home, but there are no restrictions when it comes to diesel? Maybe that diesel tanker idea isn’t so bad after all.
Stay safe and enjoy using that CR-V when the lockdown is lifted.
DOCTOR FUEL GOOD
I’m guessing this is the most random email you’ve received this month, but my elderly neighbour has made what could be a big mistake. Her Fiesta diesel was low on fuel, so with the local filling station shut due to the coronavirus, she was worried she wouldn’t make it to the medical centre and back. Her son popped over with some fuel, but ended up putting petrol in the tank.
Fortunately, my neighbour noticed before she started the engine, but not before her son had emptied the entire contents of the can into the tank. Unfortunately, it wasn’t one of those small canisters you get at a petrol station – this one held 20 litres. He was only trying to help – and we’re all guilty of doing strange things during these unprecedented times, aren’t we?
Doc, I’ve advised Ursula (my neighbour) to avoid doing anything until I’ve contacted you. Could you let me know as soon as possible what you would do to solve the issue (aside from giving the son a thick ear!).
Thanks in advance. I hope you and your better half are keeping well.
Oh dear! I would say we’ve all been there, but – touch wood – it hasn’t happened to me yet. You talk of strange things – I fed dog food to the cat yesterday and poured bubble bath down the toilet thinking it was bleach. I think I might need to get out more!
Anyway, back to the problem at hand. Did you know that a misfuel occurs every three minutes in the UK. Ursula is one of 150,000 people it happens to every year. If you would like another statistic – 95 per cent of incidents involve pouring petrol into a diesel tank.
The good news is that the engine hasn’t been started. I’m hoping that your neighbour didn’t even get as far as turning on the ignition, as this can wake the fuel pump and start the nightmare. As you’re probably aware, petrol is no good for a diesel engine. Does Ursula have misfuelling insurance cover? If so, she should speak to her provider who will arrange for somebody to come out and remove the contaminated fuel. Having said that, I’m not sure if they will send someone during the lockdown, but it’s worth asking the question.
Alternatively, she should contact her breakdown provider, but the fact that you’ve contacted me suggests she isn’t a member of an organisation. There are organisations who will come to Ursula’s house, so I’d advise her to use the Yellow Pages or go online. Maybe you could help here, because not all misfuelling companies are created equal. I remember a piece on Watchdog about a dodgy company, but it would be unfair to tarnish all the businesses with the same brush. A reputable organisation should charge between £100 and £200 to drain and clean the system, plus you’ll need some diesel to refill the tank.
Worse things have happened during the lockdown. It will take a dent out of Ursula’s purse, but reassure her that the cost would have been much worse if she hadn’t noticed the problem before starting the car.
Good luck and stay safe.
I have just read the article in the latest Diesel Car about pollution from tyres. I am sure, recently, I have seen an article regarding airless tyres. What would these be made of and would they pollute quite so much?
I am in isolation for 12 weeks – Diesel Car is one of the things that will stop me from going mad. Keep well to all the staff.
Port Navas, Cornwall
Thanks for your email – I hope you’re coping with the lockdown. Have you run out of reading material yet?
You’re right about airless tyres – the likes of Michelin, Bridgestone, Goodyear and General Motors are experimenting with the technology. I read a report in the U.S. which said that the market will be worth $392 (£315) million by the year 2027, and we could see airless tyres on our cars within four years.
Bridgestone unveiled an airless truck tyre concept in Las Vegas earlier this year and was planning to launch airless bicycle tyres at the 2020 Olympics. In simple terms, the air is replaced with a recycled thermoplastic web that holds up to 5,000 pounds. They should never lose pressure. Last year, Michelin and General Motors launched their own airless tyre concept, which they claim is longer lasting and better for the environment. They also made some bold claims about it being cheaper – but that remains to be seen. I’m not sure resin-embedded fibreglass, composite rubber and aluminium will be that affordable. Having said that, if these tyres last longer than usual – and can be 3D printed – the longer-term cost benefits could be very interesting indeed. As will the fact that these tyres are puncture and blowout proof.
As for the benefit to the environment, Michelin says it wants to be producing 80 per cent renewable tyres within 30 years. That seems a long way off – especially for the likes of me!
Keep in touch. Do send me more questions – I’m just as locked down as you.
My daughter has a 58-plate Toyota Yaris turbodiesel which is parked in a private underground car park without access to a power point. It has not moved for about three or four weeks.
What advice can I give her for the welfare of the car? I’m thinking about tyres, the battery and also the air conditioning system. None of these like to be idle for any length of time. No doubt there are other things that don’t like idleness as well.
I read that running the engine for 15 minutes every few days may help to keep the oil circulated and the battery charged etc. Her particular problem is that if she takes it for a drive, apart from it not being an essential journey and thus breaching the Covid-19 law, parking spaces are at a premium and she would undoubtedly lose her space. So is there anything she can do without going for a spin to keep things from clogging up or dying? I don’t think she has a DPF on a car that age, but I may be wrong, so running the engine shouldn’t do too much harm apart from the environment of course, which I am well aware of.
Any suggestions would be gratefully received, and I doubt I’m the first to ask this question.
Many thanks once again (I’ve previously benefited from your good quality advice).
Good to hear from you again – I hope you and your family are keeping well in these troubling times.
The good news is that it is possible to take care of your daughter’s Yaris without breaking any lockdown laws or losing the parking space. It sounds like you’re already aware of the big three things to keep an eye on: battery, tyres and the air conditioning. Assuming the battery is in good health, I recommend running the engine for 20 minutes every fortnight. When you think about it, that’s no different to leaving the car in an airport car park while you’re on holiday. I’d also suggest switching off all electrical items, but would recommend running the air conditioning for a good few minutes, just to keep it in good running order.
Without access to a plug socket, you’re unable to use a trickle charger, but you might want to consider a battery isolator. My niece uses one on her ageing Renault Clio because the car has a nasty habit of draining its battery in just a few days. They’re available for around £5 on eBay and they can be fitted in minutes. The disadvantage is that the alarm and immobiliser won’t operate, so there could be insurance implications to this method.
As for the tyres, I’d recommend over-inflating them by about 15 PSI. This will prevent flat spots, but you can also do this by moving the car a few inches forwards or backwards. You should lift the wipers away from the windscreen every fortnight, too.
Your daughter’s Yaris is unlikely to have a DPF, but it depends on the date the car was built. DPFs were first installed on the Yaris in November 2018, so if the car is older than that, you’re safe. Feel free to supply the registration plate, if you’d like me to check this for you.
I hope this information helps. Please stay safe and healthy.
Thank you very much for the advice.
I realised too late that I should have added that the car had its first new battery last November (what good timing, bearing in mind what was around the corner) so, yes, it is in good condition. The mileage, if it’s relevant, is about 85k and the car registration is **** ***.
Hello again Max,
A new battery – you must have known!
Thanks for supplying details of the car. I’ve been in touch with Toyota and I can confirm that your daughter’s Yaris does not have a DPF fitted. So that’s one less thing to worry about during the lockdown.
Let me know if I can help in any other way. In the meantime, stay safe.
I have a 2018 Skoda Karoq 4×4 2.0 TDI 150 DSG.
It has a manufacturer’s recall on it – something to do with the knock sensor (software update?). What is it and what does it do? Is this likely to be one of these things with the Volkswagen Group where it comes out running worse than when it went in? The car runs fine, and fuel economy is reasonable at around the 43-44 mpg mark. Do I need to bother with it? Or can it wait until the next service?
Yes, all fine at this end (touch wood), but it’s getting increasingly difficult to watch the news on the television. We are all living in scary times.
Changing the subject, there is indeed an outstanding recall on your Karoq. Officially, it affects 1,231 cars, and the problem involves too little torque being provided by the engine at low speeds. Put simply, the knock sensor sits on the outside of the engine block to record knocking noises. If it hears anything untoward, the ignition signal for the respective cylinder is adjusted until knocking combustion no longer occurs. There’s no fault with your engine – merely the sensor. If you take the Skoda into your dealer, they’ll update the software and you can be on your way.
Obviously now may not be the time to head to your dealer. The good news is you won’t be damaging your engine – that’s if your engine has been affected at all. However, if the knock sensor is faulty, you could experience reduced power and/or increased fuel consumption. Personally, I’d get it done when you can, but I wouldn’t lose sleep over it in the meantime. I doubt you’ll be going too far, in any case.
The biggest challenge you may face is keeping the battery recharged during these difficult times!
I hope this helps. Do stay safe and keep me posted with developments.
All the best,
Thanks Doc. Indeed, that can wait. Can’t say I’ve noticed any loss of power.
This is my first email letter to you, but I hope you don’t think this is a daft question.
After years of driving my faithful Mazda 323, I finally gave into my daughter’s demands and traded it in for a nearly-new Mazda2. It’s only a basic version, but it feels very different to my old 323. Anyway, during the recent warm weather, I returned home and spotted a small pool of liquid under the car. I didn’t think anything of it, but I noticed the same again yesterday when I returned home from my permitted weekly shop. It looks like clear water, but I’m too old to crawl under the car to see what’s what. It’s not at the front, so I don’t think it’s the radiator, but I’m worried about using it again in case there’s a problem. I can’t ask my neighbour or go to the dealer, because of the lockdown. My late husband always said you were the font of all knowledge, so I’m hoping you can help.
Thank you in advance.
Thanks for your email. As I’ve said many times before, there’s no such thing as a bad question – it’s far better to enquire first, rather than make a costly mistake. Anyway, congratulations on your new purchase. You haven’t mentioned the year of the 323, but I’m assuming it was built in the last century! The reason I mention this is because I’m wondering if it had air conditioning. All versions of the current Mazda2 are fitted with air conditioning as standard, and my educated guess is that this is the culprit.
Don’t worry, the pool of water is perfectly normal, especially in warmer weather. In hot conditions, the air conditioning system has to work extra hard and the unit can freeze over as it removes moisture from the car. When you park up, the air conditioning switches off and the ice begins to melt. This leaves a small pool of water under the car. You’ll never notice it if the road or driveway is damp – and the hotter it is, the more water you’ll see.
If it’s colourless and odourless, I’m 99.9 per cent certain this is what you’re seeing. The next time you go out in warm weather, switch off the air conditioning a couple of miles before you get home. This will give the unit time for the ice to melt, so there’ll be no water to speak of. Just be sure to switch the air conditioning on again the next time you use the car – the system should be used regularly to avoid problems further down the line.
If in doubt, contact your Mazda dealer. They will probably be happy to hear from you in these strange times.
Stay safe, Rosemary, and enjoy the little luxuries in your new Mazda.