Fuel miser on sticker, a guzzler in real life Andrew McKellar: "They don't necessarily provide an accurate representation of the fuel consumption you'll get on a daily basis." Fuel consumption figures on the windscreens of new cars aren't worth the stickers they are printed on. An exclusive Drive test has shown real world fuel consumption can be up to 40 per cent greater than what you find on the government-issued label. Drive tested three cars - a Ford Falcon, Kia Optima and Mazda CX-5 - and found each used significantly more fuel under real world driving conditions. The test took in both city and highway driving and compared the fuel economy achieved with the official rating advertised on the windscreen labels. All three cars used significantly more than the manufacturers and government claim - the Ford was approximately 20 per cent thirstier, the Kia approximately 30 per cent and the Mazda approximately 40 per cent. But the problem is not unique to these models, with most cars using more than claimed due to the nature of the test that determines the official fuel consumption rating. The test is conducted in a laboratory, usually by the car manufacturer, and most car makers have developed techniques to maximise the efficiency of the cars. Removing the spare wheel and tyre to reduce weight and improve fuel consumption in the test is one such tactic that is widely used. Andrew McKellar, executive director of the Australian Automobile Association, said consumers should only use the official figures as a guide to compare against each other and be prepared for higher numbers in the real world. "I would caution consumers from relying on the advertised or certified fuel consumption numbers that are on the stickers on the windscreen," he said. They don't necessarily provide an accurate representation of the fuel consumption you'll get on a daily basis. The Department of Transport and Infrastructure acknowledges that the test, which is used in Europe and endorsed by the United Nations vehicle standards body, is in need of changes to make it more relevant. "While a laboratory test can never represent all real world driving conditions, it is nevertheless recognised that the current UN test cycle used in Europe, Australia and many other countries around the world has not changed for many years and is in need of revision (in part to improve its predictability for real world outcomes)," said a spokesman for the department. A major review of the test by the UN vehicle standards body is currently under way. When that review is finalised and a revised test procedure is approved, Australian standards will in turn be updated to reflect the new test procedure. Consumer advocacy organisation Choice echoed Mr McKellar's calls to only use the official ratings as a tool for comparing cars in each class against each other.