AUSTRALIAN MOTORISTS are being charged too much for premium petrol, according to insurer NRMA.
NRMA analysed the price of high-octane petrol between June 28, 2006 and September 13, 2009, finding that the price differential between premium and regular unleaded had risen to between three and four cents more than it should be.
"Clearly something is not right," said NRMA President Wendy Machin.
"On July 29, 2007 the weekly average gap between regular and 98 octane petrol was around nine cents a litre, on August 30, 2009 the gap was almost 15 cents.
"We have taken the extra cost associated with refining high-grade fuels into consideration and there is still a considerable gap."
The NRMA also found 95 octane unleaded now retails for 10 cents more than regular petrol - an important consideration for many new car buyers, considering some vehicles - like the Suzuki Alto - require 95 octane fuel to run optimally.
"Many motorists have no choice but to use high-grade fuels for their vehicles and it appears they are being overcharged," Ms Machin said.
The NRMA has written to the ACCC's Petrol Commissioner Joe Dimasi demanding an investigation into the widening price gap between regular and premium petrol be launched. Mr Dimasi has yet to issue an official response.