My fuel mileage has dropped down to 15 mpg during the last tank. Never had problems before and the car would run on average around 10L/100kms in city. Now it is 26L/100kms with a fresh tank of gas. Got only 220kms on last tank of fuel - usually get 600 kms or more with both highway and city driving. Came back from a long trip and the milage was fabulous - 6L/100kms. Took vehicle to dealer and they found nothing wrong and no fault codes. But now (two days later after at dealership) my ABS, Traction control and ESP light come on all the time. Any suggestions or reason such bad fuel mileage? Reason for lights to come on?