KUALA LUMPUR: If you want to drive to Johor Baru and back on just one full tank of petrol, you would have to cruise at no more than 60km an hour and forego air-conditioning for the entire ride.

This is exactly what 18 drivers of the Shell One Tank Challenge did to successfully complete the 700km trip without the need to refill.

The drivers had left the city on Monday in 10 different makes of car, all filled with Shell Super with Fuel Economy petrol, and returned on Tuesday.

Some reached home with a quarter of a tank left, while others barely made it to the finishing point with the fuel warning light flashing dangerously.

The leading drivers were best friends Jesmeet Singh and Anand Raj who completed the trip on just half a tank.
The pair, both in their 20s, said the trick was to drive at a consistent speed and not to brake suddenly.

"We did a lot of research and also tested some of the tips before we joined the challenge.

"The journey was very tiring, as we took more time on the return trip, but we only used half our petrol," Jesmeet said.

The pair even had their air-conditioning on half of the time.

"It got too hot! We couldn't wind the windows down fully because it causes drag, so it became quite hot," Anand said.

The heat became unbearable at times for participant Naemah Ramli, who is two months' pregnant.

"Thank God, I had an understanding friend," Naemah said of her co-driver Tengku Noor Azlin Tengku Ibrahim.

Both women said they could not wait to practise the fuel-saving tips in their daily lives and will happily join a similar challenge again.

"It was fun, like a mini holiday. I got to travel with my friend and learn how to save fuel. I'd do it again in a heartbeat," said Naemah.

The convoy was joined by Guinness World Record holders for fuel efficiency John and Helen Taylor, who shared some of their own fuel-saving tips.