Tuesday, December 10The place for automotive information

The formula for the perfect car wash…

With summer supposedly around the corner, a team at Citroën, and an applied mathematician, have devised the formula for the perfect way to clean your car – but you’ll need a calculator!

Citroen car washThe team found that E = 1/t + 1W, where E is efficiency, t is the time taken for the car wash and W is the amount of water used. Citroën decided to test out the calculation by asking Arsenal first team players Per Mertesacker, Aaron Ramsey and Olivier Giroud to create the ‘premier’ car wash for Club captain Thomas Vermaelen.

In researching the formula, Citroën’s various vehicles were washed by people of differing heights in a selection of weather conditions, ranging from 4 to 20˚C. The average amount of water used and the time taken was then calculated to suit the outside temperature.

For example, a 6ft 4in car washer, such as Per Mertesacker, should take 31-minutes to clean a supermini-sized car in a low, ambient temperature of four degrees centigrade with 24-litres of water.

The research also found that, if the vehicle hasn’t been cleaned for up to three months, or has visible road grime on more than 40% of its surface, an extra 2.5 litres of water and an additional five minutes of elbow grease will be needed.

Citroën has devised five top tips to help ensure the car wash remains efficient, yet effective, by reducing unnecessary water wastage with either a bucket and sponge or a hose:

1.   If possible, wash your car after a rain shower to avoid using additional water to rinse the car first
2.   Find a shady spot to wash your car to avoid drying marks and repeat cleaning
3.   Always wash the body of the vehicle from the top down
4.   Wring your sponge or chamois out over the bucket
5.   Use a sponge to wash down with one hand and, a chamois in the other to dry off immediately

So the answer is simple – if you are planning to wash your car in the next few days, in addition to the soap and sponge, bring a calculator…