Why was lead added to petrol?
Petrol needs a certain octane level to prevent the engine from “pinging” or “knocking”. Engine knock is caused by the uncontrolled detonation of the last part of the air-fuel mixture in the combustion chamber and may damage the engine. The octane rating of a fuel is a measure of its resistance to knock – the higher the rating, the less will be the tendency of a fuel to cause knock. Adding lead compounds to petrol was the most cost-effective way of boosting its octane rating.
Why is lead being removed from petrol?
Lead has been widely used as a petrol additive since the 1920’s. However, leaded petrol cannot be used by cars equipped with catalytic converters designed to reduce harmful exhaust emissions, as lead very rapidly and permanently renders the catalyst completely ineffective. This, together with the realization that lead emitted from vehicle exhausts has the potential to adversely affect human health, resulted in it being phased out, first in North America and then across Europe and, increasingly, the rest of the world.
From what date will there no longer be lead in petrol in South Africa?
Unleaded petrol was first introduced into the South African market in 1996. Since that date, the use of unleaded petrol has gradually increased and now accounts for approximately 40% of total petrol sales in South Africa. As from 1 January 2006, lead will no longer be added to petrol in the production process and leaded petrol will no longer be marketed by the oil companies.
What octane grades of petrol will be available in South Africa after 1 January 2006?
The government has determined that three octane grades of unleaded petrol (ULP) will be permitted in South Africa (in both the coastal and inland regions) after 1 January 2006, namely 91, 93 and 95 Research Octane Number (RON). Market demand will determine which of these grades will be available in the different parts of the country. Motorists should not expect to find all octane grades available in all locations, but can expect to find a grade suitable for their particular vehicle wherever they may go in South Africa.
In addition 2 octane grades of lead replacement petrol (LRP) will be permissible, a 95 octane grade at the coast and 93 octane grade inland.
Coast (+<1200m) Inland (+>1200m)
ULP 91, 93, 95 91, 93, 95
LRP 95 93
How will the required octane grades be achieved without the addition of lead?
All the South African refineries have invested or are investing in additional facilities and more sophisticated refining technology to enable them to produce greater volumes of high octane blending components. To the extent that octane demand exceeds the ability of local refineries to supply, there will be imports of high octane blending components or of high octane petrol to ensure that demand is satisfied.
Will there be a change in the level of benzene in petrol after 1 January 2006.
Benzene levels will remain in line with the proposed regulated levels due to take effect in 2006. These are in line with the equivalent EURO specifications.
How will the prices of the different petrol grades be set?
The regulated pump prices will be determined using the same methodology as at present. This means that price setting for the unleaded grades already available (95 octane at the coast and 93 octane inland) will continue as before. The prices of the lead replacement grades will be the same as the prices of unleaded petrol of the same octane.
In the inland area, where a 95 octane unleaded grade will become available for the first time, a special “demand management levy” will be introduced on this additional grade, which will increase the pump price differential between it and 93 octane petrol, initially by 10c per liter. The reason for this is that the great majority of vehicles are satisfied inland by the 93 octane fuel which is presently the highest and, in fact, only octane available. 95 octane fuel is being made available inland to satisfy the requirements of the latest technology vehicles now being introduced by the motor industry. Since motorists will now have a choice of grades and, to avoid octane wastage, it is desirable that only those who really need 95 octane will choose to use it, – the inland demand management levy is being introduced to incentivise motorists to consider their choices carefully. At the coast, where the predominant demand will be for higher octane fuel (in general, the lower the altitude the higher the octane requirement of a vehicle) and 95 octane unleaded is presently the only available unleaded grade, there will be no additional levy on this grade.
How will I know which Petrol grade is the most suitable for my car?
A database is being compiled which will indicate the requirements of virtually all models present on our roads. This will be made widely available, including on the National Association of Automotive Manufacturers (NAAMSA website – www.naamsa.co.za) and South African Petroleum Industry Association (SAPIA website – www.sapia.co.za) websites. For each model, the data will indicate, separately for coastal and for inland operation, which grade is recommended (by the manufacturer for optimal operation) and with which other grades the vehicle is compatible (i.e. on which it will operate satisfactorily and without engine damage, but not necessarily with optimal power, performance and efficiency on certain vehicles). The motorist has the option to use any grade which is shown as being either recommended for, or compatible with, the vehicle. Motorists should remember that their driving habits may have an influence on which octane grade they find best suited to their particular needs. A set of simple guidelines, indicating the appropriate fuels to be used, will also be available on the website as well as on all forecourts.
What happens if I use the wrong octane petrol in my vehicle?
Different vehicle models have different octane requirements. Using a petrol octane grade higher than that required by your vehicle is unnecessary and a waste of money, particularly since no added benefits to engine performance or efficiency will be achieved. Using petrol with too low an octane may decrease engine performance and fuel efficiency, and may cause the engine to knock which can cause engine damage over time. It should be noted that the octane requirement of a specific vehicle is dependent on many variables, including operating conditions and the way it is driven, with octane requirement peaking under high load, wide-open-throttle conditions.
Why should I not use an octane grade that is higher than my car actually requires?
Petrol with a higher octane requires more severe refining and greater energy use in the production process. If not offset by greater fuel efficiency of the vehicle using the fuel, this extra energy use is wasted energy. This wastage results in higher emissions of greenhouse gas (carbon dioxide), which harms our environment.
The use of octane grades higher than your vehicle actually requires will cost the motorist more, cost the country more and have a negative environmental impact. At the same time, there will be no additional benefit to the drivability or performance of the vehicle.
Unleaded Petrol (ULP)
Is unleaded petrol suitable for motorbikes, lawnmowers and outboard engines?
Unleaded petrol is generally suitable for use in motorbikes, lawnmowers and outboard engines, except for a very few which use old engine technology. Refer to your equipment dealer if you have any concerns.
Can vintage and classic cars use unleaded petrol?
To avoid any possible problems these cars should in general use lead replacement petrol, although some may be able to use unleaded petrol. If you wish to use unleaded petrol, consult the manufacturer.
When I use unleaded petrol my tailpipe does not burn white as it did with leaded petrol. Does that mean that my engine performs less well?
No, it does not indicate any impact on performance. The white tail pipe when using leaded petrol is caused by lead-based deposits on the exhaust when burning the fuel. When lead is removed, the exhaust burns grey or brown. This does not mean that the engine is badly tuned, or that it has starting using oil.
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. You could also consult the NAAMSA (www.naamsa.co.za) and SAPIA (www.sapia.co.za) websites. Members of motoring organizations could also telephone their technical advice lines.
If your car can run on unleaded petrol then you can start using it immediately. If it needs protection for the valve seats, then you will have to use lead replacement petrol (LRP) which will, at least initially, be widely available. Alternatively use a bottled anti-wear additive (there will be several products available from which to choose) with unleaded petrol. However, while LRP remains available in your area, using it will be the best option.
What other benefits arise from the use of ULP?
Lead in petrol also results in the formation of corrosive compounds which particularly affect spark plugs and exhaust systems. Thus another benefit to the motorist of using unleaded petrol is that vehicle maintenance costs are reduced.
Lead Replacement Petrol (LRP)
Which cars must use LRP and why?
As well as boosting fuel octane, lead acts as a lubricant between the contact surfaces of the exhaust valves and the valve seats in the cylinder head. Certain older vehicle engines (pre mid-eighties) were made with soft metal valve seats as they were protected by the lead in the petrol. If all metal additives are removed from petrol, the soft metal valve seats may become worn and valve seat recession may result in loss of compression and power. The most critical operating conditions for valve seat recession are high speed and/or high load which leads to high valve temperatures and hence greatest wear rates.
The vehicle compatibility database which will be widely available, including on the NAAMSA (www.naamsa.co.za) and SAPIA (www.sapia.co.za) websites, will clearly indicate which older vehicles, susceptible to VSR, should use a Lead Replacement Petrol (LRP). The oil companies will either market LRP through the pumps on their forecourts or else provide a bottled additive which can be purchased and added in measured quantities to the vehicle’s tank when filling up with unleaded petrol.
What bottled additives should I use?
There are a number of anti-wear additives on the market that will protect your car’s valve seats in the same way as LRP. Additives with either potassium, phosphorus or manganese as active ingredients will provide adequate protection if dosed correctly in accordance with the manufacturers recommendations.
What are the consequences of using lead replacement petrol (LRP) if my car is fitted with a catalytic converter?
LRP should not be used in cars fitted with catalytic converters, because certain of the additives used may adversely affect the catalyst. For that reason LRP, will only be sold through larger diameter nozzles which will not fit the filler pipes of vehicles requiring unleaded petrol.
When will it be compulsory for cars to be fitted with catalytic converters?
As from February 2005, all new petrol-powered passenger and light commercial vehicle models introduced in South Africa need to meet mandatory maximum emission levels and hence should have been fitted with a catalytic converter. As from January 2008, all new petrol-powered vehicles of all types, whether they be new or existing models, must be fitted with catalytic converters. There is no requirement for cars built before these dates to be retrofitted with catalytic converters. In excess of 70% of all new cars are already fitted with catalytic converters.
Use of suitable bottled anti-valve seat recession (AVSR) additives?
Anti-valve seat recession additives are very easy to use. Simply inject or pour the required amount of additive into the fuel tank prior to filling up with unleaded petrol. These additives provide valve seat recession protection similar to the protection that the lead in leaded petrol provided.
How do I know that anti-valve seat recession additives will protect my engine?
Anti-valve seat recession additives can substitute for lead replacement petrol 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. Be aware that protection is needed most when the vehicle is operated under high engine speed or load conditions, such as during extended periods of highway driving whilst towing a heavy trailer.
Will using more of an anti-valve seat recession additive than the recommended amount provide better protection for my engine?
No. You should not use more than the recommended amount of additive.
Will using an anti-valve seat recession additive, in addition to using LRP, provide better protection for my engine?
No. You should use either an AVSR additive or LRP. Some additives may be unsuitable for mixing with LRP. Different additives could also be incompatible with each other and so it is advisable to stick to one.
If my car currently uses ULP, will using LRP or an AVSR additive provide it with additional protection?
No. Continue to use your usual grade of ULP as your car does not need the protection that LRP or AVSR additives provide. If your car is fitted with a catalytic converter, using LRP or AVSR additives could damage the catalyst. You must use only ULP as recommended in the vehicle’s handbook.
What will the new Sulphur content be in Diesels?
Two grades of diesel will be available, as is currently the case. A standard grade available nationally of 500 ppm (parts per million) maximum sulphur content, as well as a niche grade lower sulphur diesel of 50 ppm maximum sulphur.
Will the new spec diesel effect maintenance cost and oil change intervals?
Motor manufacturers have indicated that the lowering of sulphur content will allow many vehicles to extend their oil drain intervals, which will reduce maintenance costs.
Why is sulphur being reduced in diesel?
Compounds containing sulphur occur naturally in diesel. The reason for reducing sulphur from 3 000 ppm to 500 ppm is to reduce vehicle emissions and thus improve urban air quality. However, if the vehicle is poorly maintained, noxious gasses and particulates will still be emitted regardless of the improved fuel quality.
Will lubricity be affected?
Certain hydrocarbon compounds (polar and aromatic compounds) present in diesel fuel have a natural lubricating effect on fuel pumps and fuel injectors. When they are removed during the fuel desulphurisation process the lubricity of the fuel is reduced. Therefore lubricity additives will be used in the 500 and 50 ppm sulphur diesel grades to ensure that the specified lubricity levels are maintained.
What is the cost involved, why more?
The lower sulphur diesel grades will cost more than the higher sulphur diesel grade that they are replacing, in line with international market prices.