Petrol in Australia!
Whats the difference between unleaded and premiem

Regular Unleaded Petrol

Regular unleaded petrol (ULP) was introduced to market in 1986, to enable new vehicles to operate with a catalytic converter, a device designed to reduce exhaust emissions. ULP is the recommended fuel for the majority of passenger cars made since 1986.

Under the National Fuel Quality Standards, regular unleaded petrol is required to have a minimum Research Octane Number (RON) of 91.

Premium Unleaded Petrol

Premium unleaded petrol (PULP) is designed for engines that have a high compression ratio. Therefore, it is formulated with a higher-octane level to prevent knocking and to optimise performance. Under the National Fuel Quality Standards PULP is required to have a minimum RON of 95, however a number of premium unleaded products are formulated with a RON of 98.

Lead Replacement Petrol

The sale of automotive leaded petrol was phased out in Australia by the Commonwealth Government on 1st January 2002. Lead Replacement Petrol (LRP) was developed as a substitute to leaded petrol, which was necessary for most cars produced before 1986. Lead additives raised the octane of the petrol, and provided protection against valve-set recession. LRP has been designed with the same octane levels, but other additives are now used to protect the engine from valve and valve seat damage. LRP has a RON of 96.

Some vehicles that currently run on leaded petrol may be able to use a high-octane PULP, however an aftermarket anti-valve seat recession additive or modifications to the engine may be needed to protect the engine.


Automotive diesel fuel is designed for compression ignition diesel engines. A diesel engine has a higher compression ratio, resulting in lower fuel consumption than an equivalent petrol engine.

From 31 December 2002, it has become mandatory for all diesel sold in Australia to contain less than 500 parts per million (ppm) sulfur, typically referred to as Low Sulfur Diesel. This compares to previous typical production with around double that level.

Liquefied Petroleum Gas

Liquefied petroleum gas (LPG) is the most commonly used alternative fuel for vehicles, consisting mainly of a mixture of propane and butane.

Cost savings may be achieved by using LPG, dependant on the price differentiation with petrol and the engine conversion costs. LPG can also provide some environmental benefits, with estimates suggesting that exhaust and evaporative greenhouse emissions are approximately 15 per cent lower from vehicles using LPG compared to petrol. A national fuel quality standard for automotive LPG is due to be introduced in early 2003.