Hounslow has more thefts of fuel from vehicles than any other London borough, according to the Metropolitan Police.
A total of 175 thefts were reported between 2009 and 2012, but there were only five prosecutions.
Greenwich, Lewisham, Southwark and Merton were the other London boroughs in the top five for fuel theft.
Metropolitan Police said the majority of thefts were from commercial haulage vehicles which were prominent in Hounslow.
It said the area served both Heathrow airport and central London and advised that parking goods vehicles in areas with good lighting and CCTV was the most effective way of reducing opportunities for thieves to steal diesel.
Across London, reports of fuel thefts have increased by a third in three years. In 2009 there were 389 reports, while in 2012 there were 510.
The AA said the fuel was usually either siphoned out through the petrol cap or cars were drilled from underneath, causing considerable damage.
A spokesman from the AA said: “On average we have attended one fuel theft a week and we’ve noticed that it’s on the increase.”