Car clinic: Choosing the right car cover, when tyres are too old, where to hold a court hearing and an oily Porsche Boxster

Your motoring problems solved

The Car Clinic experts

Tim Shallcross used to train AA patrols to fix cars. Now he advises the Institute of Advanced Motorists.

Dave Pollard has written several Haynes manuals and has tested just about every car-related accessory.

Nick Freeman is a solicitor who runs a legal practice in Manchester and specialises in road traffic law.


Q. My Porsche Boxster S sends out blue smoke from the exhaust on start-up and consumes engine oil. Apparently this is common and there are no apparent leaks. Would I benefit from changing from the recommended oil (Mobil 1 0W-40) to one with higher viscosity?

RS, Chobham, Surrey

A. Your Porsche’s engine is designed in a “flat six” configuration: its six cylinders lie horizontally. This position means that some oil always collects in the cylinders when the engine is turned off (as opposed to the more common configurations, in which the cylinders are vertical or sloping, meaning oil drains back to the engine sump). A slight puff of smoke on start-up as this oil burns off is common — and harmless.

If you remain worried about excessive oil consumption, have your garage look at the air/oil separator (AOS). This is a device fitted to reduce polluting emissions from the engine; if it fails, oil is sucked into the engine inlet and burnt, producing smoke not just on start-up but at all times. If the AOS is not to blame, a cylinder compression check will show whether engine wear is causing excess oil consumption.

If no fault is found, a change to a higher viscosity oil might reduce oil loss. Porsche sanctions the use of a thicker 5W-40 oil for temperatures above -25C, so there will be no warranty issues provided the oil is also fully synthetic. The thicker oil is unlikely to stop the puff of smoke at start-up, though.



Q. Our garage is so full of stuff that there isn’t room for a car. Can you suggest a protective cover for our new Nissan Micra?

RM, Bosham, West Sussex

A. A car cover should be similar to a Gore-Tex jacket: although rain must not get in, dampness from the inside needs to be able to escape. Without that one-way permeability, moisture from the ground beneath the vehicle will evaporate, become trapped under the cover and eventually cause corrosion.

Classic Additions ( has a lightweight cover designed for cars that are used on a regular basis: it is light and easy to fit, remove and store. It comes with a cable lock and three straps that wrap around under the bodywork for security.

If you use the car rarely, opt for the company’s heavy-duty cover, which has a soft cotton lining, a storage bag and seven straps. The prices for these items  are £93.60 and £141.60 respectively, plus £8.40 postage.

In a similar vein, Hamilton Classic ( offers a breathable, fleece-lined outdoor cover with storage bag for £155 plus £11 postage. The fleece lining makes it less likely to stick to the car’s bodywork, which is an important consideration in the long-term storage of classic cars.



Q. We have owned our nine-year-old Toyota Yaris since new but have never replaced the rear tyres. They still look almost unused, but having read a news story about a coach crash that was blamed on an old tyre, I’m wondering whether it would be safer to change them. My garage advised against putting the rear tyres on the front wheels as it could affect the steering. Was this good advice?

PS, Guildford, Surrey

A. Provided the two rear tyres are the same make and type, putting them on the front wheels will not affect your steering in any way. It is actually good practice to fit any new tyres to the rear, even if it means swapping used ones to the front, as it ensures that the back wheels have the most grip and reduces the possibility of the car spinning on a slippery road (this applies whether the car is front-wheel or rear-wheel drive).

In your case, it is probably time you got rid of all the tyres, though it is hard to give a definitive answer as to what is considered too old, as rubber ages at different rates depending on how it is used.

There is no legal maximum age, but the advice from most tyre manufacturers, and from motoring organisations including the Institute of Advanced Motorists, is that a tyre should be replaced irrespective of condition once it is 10 years old. For caravans and trailers, which are often left standing for long periods, the advice is to replace them after six years.

It is easy to check the age of any tyre produced from 2000: look for the four-digit code on the sidewall after the letters “DOT” (a reference to the US Department of Transportation). The numbers stand for the week and year of manufacture. The digits “4604”, for example, would mean the tyre was made in week 46 (mid-November) in 2004.



Q. Earlier this year I sold a car to a customer who had travelled down from Scotland to Lancashire. I am a sole trader. Despite being happy with his purchase at the time, two months later the customer called to say that the car had seized up, that he wanted a new engine and that I should pay for it. I have now been sent a summons from a court in Ayrshire. As the transaction took place in England, am I entitled to have the case moved to my local court?

NB, Preston

A. Under European law the general rule is that the case should be brought in the country where the defendant is domiciled. As this is a contractual matter, the case can also be brought in the country where the contract was performed. Assuming you do not trade in Scotland and there was no credit agreement to fund the purchase, this means the case should be brought in England.

Your first step should be to “dispute jurisdiction”, which is essentially you asserting that the case is being brought in the wrong country. There may be an option to this effect in the “acknowledgement of service” you will have received in the paperwork. If there isn’t, you should write to the court, outlining your position. It is crucial you do not do anything that suggests you are content for proceedings to take place in Scotland.

In a case such as yours, where the claim is for a specified sum of money and the defendant is an individual (this includes you as a sole trader), it is usual — in England and Wales — for the case to be transferred automatically to the defendant’s local county court. If the defendant is a company, or the case is not for an identified figure, an application to transfer can still be made — but whether it is granted will depend on the circumstances of the case and will be at the discretion of a judge.





Got a car problem?

Email your question to, or write to Car Clinic, Driving, The Sunday Times, 3 Thomas More Square, London E98 1ST, with a daytime phone number, your address and as much detail about your car as possible. We can’t reply personally, so please don’t send original documents or SAEs. Advice is offered without legal responsibility.