Fuel producers have hit back at a test of high-octane fuels, which suggested that these more expensive ‘super’ fuels offer few additional benefits.
According to Which? Car magazine the fuels “don’t save you money, improve your car’s performance or save the environment”.
However, BP said that its stands over the claims of the benefits of its Ultimate fuels.
It also criticised the magazine’s tests, which only used three mainstream models - a Ford Focus, Renault Megane and Volkswagen Golf.
“It is simply not possible to obtain a reliable comparison of the fuels based on short-term tests with one or two vehicles,” said a BP spokesman.
“BP Ultimate has been tested over many thousands of miles using different makes and models of cars, engine sizes and older and newer model vehicles.
"All testing by BP is carried out in accordance with industry standard test procedures and a significant amount of this testing has been conducted by independent laboratories.”
Fuels such as BP’s Ultimate, Shell’s V-Power and Tesco’s Super Unleaded are more expensive at the pumps but are promoted as being able to optimise a car’s economy and increase power.
Which? Car compared the three super fuels against standard fuels.
It found that Shell V-Power gave a 1.6-litre Ford Focus a “marginal power increase” and that Tesco Super Unleaded actually decreased the power of the Focus.
In response Shell said: “Shell V-Power has been designed for those drivers seeking petrol that gives them improved vehicle performance and responsiveness.
"Shell V-Power's unique formulation includes a friction modifier, an octane rating of 99 RON and a powerful cleaning formula designed to prevent power-robbing deposits forming.”
Corresponding with the oil companies’ assertions that highly tuned models will benefit most from high-octane super fuels, the magazine found that Volkswagen’s supercharged and turbocharged Golf 1.4-litre TSI “responded well to Shell V-Power, but there was little to choose between super fuels and ordinary petrol on economy and emissions”.
The magazine also said that “economy and performance of the Renault Megane 1.5-litre diesel were both slightly worse using BP Ultimate diesel, the super fuel furthest from the marketing claims in the test”.
Which? also said that each super fuel “had only a marginal effect on the emissions of measured pollutants”.
Editor Richard Headland, said: “For many cars it’s a waste of money paying over the odds for so-called super fuels. The standard fuels we tested were all up to the job.”