What you may not know is that there is also a millennium fuel bug, which will see leaded petrol banned from forecourts by the end of this year. Fears about the phasing out have triggered lots of calls to the AA's Technical Advice department.
Yet in many cases, they need never have called in the first place. For instance, owners of older model Nissan Micras driving an average of 12,000 miles a year over the last three years will have spent almost pounds 900 extra by sticking to four-star leaded petrol when they could easily have switched to unleaded.
"It has come as a nasty shock to some drivers. Particularly those who asked a garage years ago and were advised wrongly," says Dave May, manager of AA Technical Advice. "Virtually all Japanese models have been able to run on unleaded petrol since 1978. As can older British cars with Japanese engines such as the Triumph Acclaim. Many popular models, such as some Ford Escorts, Orions and VW Polos, can switch to unleaded petrol."
So why is the British motoring public so badly informed? Leaded petrol has been banned thanks to the EU Environment Council in June 1997 and will only be available after January 2000 to "specialist interest groups" like classic car clubs.
But why do we need lead at all? Here comes the science stuff: lead in petrol acts as a protective barrier between the exhaust valve and the valve seat into which it fits. Without lead, or an alternative seat protector, "soft" valve seats can wear away causing stalling and loss of power and eventual breakdown.
According to an RAC spokesman: "We have already come across a few rogue garages which are recommending expensive engine work on cars that obviously don't need it. Our members can phone a technical helpline which will be able to answer most enquires. In the first instance though, motorists in doubt should contact their dealer."
For the majority of modern cars there isn't much of a problem, but if you do have an older "classic" there are several options. Firstly you must join the relevant classic car club who will have all the necessary information and specialist contacts. Then you have several choices.
If you only use your classic for a few thousand miles each year, for fair weather fun, the chances are that because it has been running on leaded for so long, the engine has enough "leaded memory" to survive. Some specialists say this could be for up to 20,000 miles.
At that point and if you are a high mileage old car user you might consider installing higher specification valve seats. On a simple four-cylinder engine that will cost pounds 100-pounds 250, but on a complicated V8, budget for several thousand.
There is a third alternative though - additives. In countries where lead has been banned, including Germany, Denmark, Sweden and Austria, lead replacement fuel and additives are used for lead-only cars. Lead replacement fuel is not yet sold in the UK and there is no British standard for the available additives which are currently undergoing engine durability tests.
Over the counter you can buy STP Lead Substitute, which is phosphorous based, whilst Wynn's sodium-based Lubrivalve has been successfully used in the USA and New Zealand.
So how long have we got until the lead runs out? According to the UK Petroleum Industry Association: "We anticipate that sales will cease by the third quarter of 1999. We have to allow for retailers to deplete stocks and flush out their systems."