On January 1st 2000, Western Australia becomes the first Australian State to follow international trends and will be a totally unleaded market. Leaded petrol is being phased out first in WA with the other States to follow suit over the next couple of years. For owners of older cars this does not however mean the demise of their vehicles. Leaded petrol has been around since the 1940s. It is now being phased out worldwide. Lead was first discovered to provide an octane boost to petrol in the late 1920s and this feature was fully exploited to enable the design of improved performance engines for Spitfire planes during World War 2. Thereafter its use became widespread as an economical means of octane enhancement until the late 1980s when it began to be phased out in the US being incompatible with the catalytic converters mandated to achieve the clean air standards legislation. Most cars built before 1981, and many built before 1986, were designed to run on leaded petrol and have engines with soft exhaust valve seats. Abnormal exhaust valve seat recession (VSR) can occur when these vehicles are operated on unleaded fuel. This is because lead, in addition to providing octane improvement, also acts as a solid lubricant between the exhaust valve and the soft exhaust valve seat, preventing the valve from recessing into the cylinder head. VSR occurs when an exhaust valve impacts upon a soft cast iron valve seat at engine operating temperatures. VSR is exacerbated by high operating engine temperatures caused by high speed and/or high load conditions. Most vehicles of modern design have hardened valve seats or inserts that are insensitive to VSR. VSR can cause valve burning and loss of performance and, if allowed to progress unchecked, will ultimately result in loss of compression and engine failure. There are a number of measures that can be taken to prevent this occurring. Owners of older cars can either have hardened inserts fitted to the exhaust valve seats of their cars' engines - a relatively expensive modification, use a valve seat recession protection additive with unleaded petrol or use lead replacement petrol (LRP) with the additive pre-mixed. Valve seat recession protection additives act to replace the protection offered by lead. A number of additive chemistries are available which reportedly protect against VSR but independent tests have identified additives containing phosphorus as the most effective of these. Valvemaster is the phosphorus based VSR protection additive. It has been extensively proven in independent tests. Additionally, Valvemaster has had many years of successful use in North America, New Zealand and elsewhere since the global phase out of leaded petrol began and is the only VSR protection additive to have US EPA (Environmental Protection Agency) registration. Valvemaster is not a new product. It was originally developed in the US by Du Pont as a carburetor detergent. It was used extensively worldwide during the 1960s and 70s so many of the cars that now require Valvemaster for valve seat protection have a previous history of using petrol treated with Valvemaster. Valvemaster was subsequently discovered to offer excellent VSR protection and has been used to treat many billions of litres of petrol since the early 1980s.In New Zealand which went totally unleaded in 1996, Valvemaster is available at all service stations and has been used almost exclusively there. It has provided the necessary protection to many of the older Australian and European car models designed to run on leaded petrol and that are still common on New Zealand and Australian roads. Valvemaster gives effective protection against VSR at treat rates in the range of 11 to 30 ppm by weight of phosphorus depending upon driving conditions. A Treatment level of 30ppm by weight phosphorus gives very good protection under virtually all driving conditions. Independent tests undertaken by engine laboratories in Europe and the US proved Valvemaster to be the most effective VSR protection additive and the next best protection to lead. Valvemaster has been tested in Australia at Melbourne University's internationally recognised engine laboratory. A 3.3 litre Holden engine was used. Valvemaster passed a more severe test than the draft Australian Standard AS4430.2. In addition to VSR protection, Valvemaster keeps carburetors and port fuel injector systems clean. It is also effective at protecting fuel tanks and systems from corrosion. Valvemaster is either added to bulk petrol which is then sold as lead replacement petrol (LRP) or is sold as an aftermarket product which the motorist adds to the tank when refueling. In addition to LRP, Valvemaster will be available in two product forms. A Valvemaster applicator has been developed for use on the forecourt. One applicator treats fuel fills up to 20 litres. This product is what is generally used in New Zealand. A 250ml bottle with a dispensing device, graduated in litres of fuel treated, is also available for users who regularly want to dispense either large amounts, i.e. agricultural machinery, boats, etc, or small amounts not corresponding to the 20 litre applicator. Where LRP is available, these products will be offered for engines that may require supplementary (heavy-duty) protection e.g. high risk vehicle that are used for heavy towing or driven at motorway speeds for prolonged periods. Valvemaster is a registered trademark of the Associated Octel Company Limited.