Car overheating remedies

Let’s start with prevention is better than cure. Many motorists never check their coolant level but it’s worth doing at least once a month. If it needs a regular top up then this also suggests a fault which needs investigating.

If, however, after all this your needle does start to rise ominously in that holiday traffic jam then there are a few things you can do.

  1. Turn off the air conditioning. This will take some of the load from the engine so it will produce less heat.
  2. Switch the heater to Hot, point the air towards the windscreen and turn on the heater fan. You’ll get a little heated but it will cool the engine.
  3. With automatic gearbox, when stationary, put the car in Neutral instead of Drive. Less heat and better coolant circulation.
  4. On downhill sections, leave car in Neutral and let it roll (but at no more than 10 mph). Don’t turn the engine off as this will rob your ability to break and steer.
  5. Turning engine off for short periods may actually aggravate the problem. If the needle goes off the scale though, turn off and consider yourself broken down!
  6. Try and get out of the jam as soon as you can – either to park or take a side road where speeds of 20 mph plus will (hopefully) cool the engine.
  7. When you can do so, park for at least 30 minutes to let the engine cool then top up the water. If you are not familiar with how to do this then call the RAC or whoever, otherwise you might scald yourself or damage the engine.

Keep cool!

Twenty is Plenty

20 mph limits are appearing in several towns and cities. Critics claim that such a move would significantly slow down journey times.

Not so! I shall try to demonstrate.

The limit applies to residential roads, not A and B roads.

There are very few residential roads which are more than half a mile long.

One cannot enter or exit a residential road at speed, certainly not at 20 or 30 mile per hour. It is reasonable to assume that the car might stop or be slowed to a few miles per hour at the start and end of each road.

With that in mind, I’m going to construct a worst-case scenario for a 5 mile urban journey. This assumes:

Only residential roads are used.
Each such road is half a mile long – therefore 10 roads are used in total.
The car never stops, just drops to 5 mph to leave one road and enter the other.

At 20 mph, after allowing 17 feet needed for acceleration and braking between 5  and 20 mph, the car will travel at its maximum of 20 mph for 863 feet in approximately 29.5 seconds.
Over the whole journey, distance travelled at 20 mph is 29.5 x 10 = 295 seconds.

At 30 mph, after allowing 25 feet needed for acceleration and braking between 5  and 30 mph, the car will travel at its maximum of 30 mph for 855 feet in approximately 19.5 seconds.

Over the whole journey, distance travelled at 30 mph is 19.5 x 10 = 195 seconds.

The 20 mph journey will therefore take just an extra 1 minute and 40 seconds for 5 miles.

This, however, assumes absolutely ideal conditions. In practice, the car will come to a halt several times, the roads won’t be a nice half a mile long and maximum speed won’t be achievable because of other road users.

Because of this, the 20 mph limit probably costs the driver less than a minute over 5 miles in what, in urban terms, is quite a long journey.

And perhaps saves the live of a child.