Lead replacement petrol phase-out - Information to motorists

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When the Government banned leaded petrol, oil companies introduced lead replacement petrol, oil companies introduced lead replacement petrol (LRP) specifically for vehicles whose engines needed the added protection that lead in petrol provided.  As there are fewer and fewer vehicles on the road that require it, more and more petrol stations have withdrawn LRP, and its availability is now very limited.

There are, however, a number of alternatives that will allow motorists whose cars currently run on LRP to continue to use their vehicles.

If you are currently using unleaded petrol exclusively this will not affect you and you need read no further.

If you currently use LRP you will still be able to run your car

  • You can buy special lead replacement additives in bottles or syringe-like applicators instead. You simply pour these into the tank every time you fill up with the appropriate grade of unleaded petrol (Premium or Super) recommended for your vehicle. If you are unsure as to which grade to use, use Super Unleaded Petrol until you have obtained professional assurance that your car can use Premium Unleaded. You might want to keep a supply of additive in your car boot in case you drive into an area where LRP is no longer available.
  • Many older cars can safely use the appropriate grade of ordinary unleaded (Premium or Super) petrol without using additives and without any alteration to the engine. Others may only need a simple adjustment to the ignition timing. Check to see if your car really needs special additives.

Why do some cars need leaded petrol or LRP?

Lead in petrol did two things. Firstly it increased the fuel's octane rating making it less prone to 'knock' or 'pinking', this is when the fuel in the engine burns in an uncontrolled manner, potentially causing damage to the engine. Secondly it protected the engine's exhaust valve seats from wear. Cars that are designed to run on unleaded fuel have very hard valve seats that resist wear.

As part of a European strategy to reduce pollution from road traffic and improve the air we breathe, leaded petrol was banned from general sale from 1st January 2000. However, as there remained on the roads a significant number of cars that needed leaded petrol, oil companies introduced Lead Replacement Petrol - higher-octane Super Unleaded with a Potassium additive to protect the valve-seats.

Why will LRP be disappearing?

Environmental standards mean that all petrol cars built since 1993 and sold in the UK are fitted with catalytic converters and can only run on unleaded petrol, while many cars built before that date are also capable of running on unleaded petrol. As older cars that cannot run on unleaded are scrapped and replaced, sales of LRP have fallen and are continuing to fall. It is expected that over the next 12 months the low level of sales of LRP will cause oil companies to withdraw it from sale. However, while LRP may be disappearing, there are alternatives available that means that older cars can continue to be run.

What alternatives are there?

  • If your car needs LRP or Leaded Petrol to protect the valve-seats from wear you can fill up with the appropriate grade of unleaded petrol and add a lead-replacement anti-wear additive. Some additives designed to protect valve-seats also contain octane-boosters. These will be available in bottles or syringe-like applicators from your service station and from motor accessory shops.
  • If your car uses LRP for it's higher octane rating alone, you can use Super Unleaded petrol, or you may be able to convert your car to run on Premium Unleaded by simply having the ignition timing retarded.

How do I know if my car can run on unleaded petrol?

First consult your vehicle's handbook. If, after doing this, you are still unsure whether your car could use unleaded petrol you should seek advice from your local dealer. Members of motoring organisations could also telephone their technical advice lines.

What should I do now?

First find out whether your car can use unleaded petrol:

  • Consult your vehicle handbook;
  • Ask your local dealer;
  • If you are a member of a motoring organisation, call their technical advice line or visit their website;
  • The 'Unleaded Petrol Information Manual - 3rd Edition' published by Autodata (ISBN 0 85666-544-4) gives details of vehicles manufactured up to 1989 which can use unleaded petrol.
  • If your car can run on unleaded then you can start to use it immediately.
  • If your car only needs LRP for the higher-octane rating you can use Super Unleaded instead, or you may be able to have your car's ignition timing altered to use Premium Unleaded.
  • If your car needs protection for the valve-seats then you will have to consider using anti-wear additives, or have hardened valve-seats fitted. If you are going to use anti-wear additives then decide in advance which is the most suitable product for your needs.  If LRP is still available in your area then you can continue to use it.

What additives should I use?

There are a number of anti-wear additives on the market that will protect your car's valve seats like LRP. Additives with active ingredients of either potassium, sodium, phosphorous or manganese have been shown to give protection to exhaust valve-seats. Although no additive is as effective as lead, it has been shown that correct dosing will provide adequate protection to exhaust valve-seats under normal driving conditions. There is currently no British Standard for anti-wear additives so motorists are advised to exercise caution when choosing an additive.

The Federation of British Historic Vehicle Clubs (FBHVC) has independently tested a number of anti-wear additives on the market, and although results varied, they have officially endorsed several brands. Products endorsed by the FBHVC will carry their logo and the words "Endorsed by the FBHVC" or "This product has been subjected to a valve-seat recession test by an independent test-house on behalf of the Federation of British Historic Vehicle Clubs. The results of the test indicate that the level of valve-seat protection is likely to be adequate for all normal driving, but not including racing or other exceptionally arduous uses". A list of these additives can be found at www.fbhvc.co.uk.

If your car will need an anti-wear additive, you should think now which particular product is most suitable for your needs. Having chosen an appropriate additive it is recommended that once you start using it you should continue to do so even if you find LRP available elsewhere. Similarly, once you have chosen an appropriate additive you should not mix it with other additives, or regularly change the additive you use. This is because there is a small possibility that mixing of some anti-wear additives on the market could result in engine damage. However, the occasional use of LRP or change of additive is unlikely to cause a problem.

How do I know that anti-wear additives will protect my engine?

If you have been using LRP without experiencing any difficulties then you should experience no difficulties using anti-wear additives with unleaded petrol. Research, and the use of anti-wear additives in other countries, has shown that they provide adequate protection in normal driving conditions. Anti-wear additives can substitute for LRP quite satisfactorily provided that you choose an additive from a reputable manufacturer that is specifically designed to protect valve seats and you use it exactly as instructed on the packaging. However, neither LRP nor anti-wear additives are as effective as leaded petrol in protecting your car's exhaust valve-seats. If your car cannot run on unleaded petrol, and you are planning to run it at high engine operating speeds - such as extended periods of motorway driving or towing a heavy trailer - you may need to take further precautions. Further information is available at the bottom of this page.

Will using more of an anti-wear additive than the recommended amount provide better protection to my engine?

No. You should not use more than the recommended amount of additive.

Will using an anti-wear additive in addition to LRP provide better protection to my engine?

No. You should use EITHER an anti-wear additive OR LRP. Some additives may be unsuitable for mixing with LRP. Different additives could also be incompatible with each other so it is advisable to stick to one.

If my car currently uses unleaded petrol will using LRP or an anti-wear additive provide additional protection to it?

No. Continue to use your usual grade of unleaded petrol as your car does not need the protection that LRP or anti-wear additives provide. If your car is fitted with a catalytic converter using lead replacement petrol or anti-wear additives could damage the catalyst, you must use ONLY unleaded petrol as recommended in the vehicle's handbook.

Will a "Fuel Catalyst" or other device enable me to run my car on unleaded petrol without damage?

A number of devices are commercially available which are claimed to provide protection to engines with soft valve seats when using unleaded fuel. The Department for Transport does not endorse specific devices and recommends that motorists seek independent test evidence to prove the effectiveness of any device before they purchase it.

I have heard that a small allowance of leaded petrol will continue to be available. Will I be able to obtain any of it?

An allowance of leaded petrol, up to 0.5% of total petrol sales, may be marketed for classic vehicles. This was intended for use in high-performance classic vehicles and classic motor-racing. However, as LRP and anti-wear additives provide adequate protection for the majority of vehicles with soft-valve seats, much of this allowance is not taken up. Details of service stations supplying leaded petrol can be found on the FBHVC website at www.fbhvc.co.uk or at www.leadedpetrol.co.uk.

What do I do if my car is used for motorway driving or towing?

Valve seat wear is more severe at high engine operating speeds and temperatures. If your car covers many miles in situations likely to cause these conditions, such as driving at motorway speeds or towing a heavy trailer or caravan, LRP or anti-wear additives may not provide enough protection and you may need to consider fitting hardened valve seats (see below). To maximise the life of your vehicle it is always advisable to have it well maintained.

If your car is often used for motorway driving or towing and it cannot run on unleaded petrol you should consider having hard valve seats fitted to the cylinder head. This will then allow your car to run on unleaded petrol without damage and you will no longer need to use LRP or anti-wear additives. If you are unsure whether you need to go to this expense you should check the tappet clearances of your engine frequently while using LRP or an anti-wear additive. If the exhaust valve clearances reduce more rapidly than normal this is a sign of the valve seats wearing. In the short term wear can be accommodated by adjusting the tappet clearances however in the long term you will need to have hard valve seats fitted to the cylinder head.

If it is available in your area you may still be able to take advantage of the small quantities of Leaded Petrol on the market, which will give your engine the protection it needs at high-operating speeds. However, you should be aware that you may not be able to find leaded petrol outside your area, so this will not be an option for everyone.

How much will it cost to have hardened valve seats fitted to my car's engine?

Check with your local garage, the cost will depend upon your car. A straightforward four cylinder engine like that of a Morris Minor would be cheaper to convert than a larger and more specialised engine would be. A small minority of cars will be unable to have hardened valve seat inserts fitted.