I DRIVE a 2008 model Geely 1,3. Sometimes when I switch the aircon on it loses power drastically. I have been advised to change the petrol filter, but it made no difference. Is there anything one can do about it?

Bernard

Bernard, this is a well-known phenomenon on small-engined cars fitted with an aircon. When you switch on the aircon it's almost as if somebody is applying the brakes. The reason for this is that some of the engine power used to propel the car is suddenly diverted to driving the aircon compressor.

Let's say you are travelling at a constant speed of about 100kmh on a level road. The engine will be putting out about 12kW just to cancel out the effect of the forces opposing your movement: friction in the drivetrain, rolling resistance and air resistance.

If you suddenly divert 5kW of this power to the aircon compressor, the propelling force available at the wheels will immediately be less than the opposing forces, hence the impression that an invisible hand is holding you back.

A bigger-engined car will experience the same effect, but the engine has enough torque to quickly increase the revs (and thus the power output), to make up the deficit, and therefore the drop-off in power delivered to the wheels is less noticeable.

The latest aircon designs fitted to small-engined cars are more efficient (use less power) and the electronic engine management systems have also become clever enough to switch off the aircon briefly when you need a spurt of extra power for accelerating, or on an uphill stretch of road. The best you can do is to use the aircon judiciously.

Try to switch it on only in slow-moving, stop-start traffic. The effect will be less noticeable then, and it is also the time when you need an aircon the most, because there isn't enough natural airflow to provide cooling when you open the windows. Don't avoid using the aircon altogether - it needs to be used at least once a week, year round to prevent the seals in the system from drying out. Use it as a de-mister in winter.

The letter about Unity Insurance published in your column of February 24 made me think of my own experience with an insurance company recently. On November 19 I was involved in a car accident. On the same day I logged a claim with my insurer. After a week of personally following up on the progress of my car, I was advised that the claim was rejected because I had a fare-paying passenger in my car. It so happened that on the day of the accident the passenger, who paid on a daily basis, did not pay. The claim is reflected in my claims history, though I had to fix my car out of my own pocket. Could you please look into this matter.

Derick

Derick, the clause stating that you are not covered by insurance while you are transporting fare-paying passengers is a pretty standard one in ordinary domestic policies across the insurance industry. (The interpretation thereof might differ slightly from insurer to insurer, and this must be clarified with each insurer.) The reason given for this clause is that statistics show that clients who transport people for reward have a higher likelihood of claims for personal liability being instituted against them for injury or death of a passenger.

Such claims, which are often for huge amounts, might be passed on to the insurer. Because of this increased risk, when a company does offer you cover for transporting fare-paying passengers, it will be issued as an extension of the normal benefits and an additional premium will be payable.

All of this is reasonable and understandable. What is neither reasonable nor understandable is why your claim, which was purely for blikskade (tin damage) to your car, and had nothing to do with injury to a passenger, was rejected.

I am sorry to say, but this is an instance of a company using every possible escape route to avoid honouring a claim. As such, I think it is iniquitous, and I would like to hear how a spokesperson for the insurance industry justifies this.

The fact that your passenger did not pay his fare on the day of the accident will make no difference to your case - they will simply say he would have settled up with you the next day.

Whether a repudiated claim is still recorded as a claim in your claims history is something that differs from company to company. Those that insist on doing it give reasons such as the costs involved in processing the claim. They might, for example, have appointed an assessor who has to be paid, even though the claim was rejected.

What comes out of this is the importance of discussing every possible scenario with the broker through whom you arrange your vehicle insurance. And I would advise you to make use of a broker - insurance is too complex a field for the layman.

If you are occasionally going to give a friend a lift for payment, write it into the contract, even if it means a higher premium. If the vehicle will occasionally be driven by persons other than the insured, list these occasional drivers on the contract. Verbal assurances are not enough.