Unleaded Fuel and LRP in your Volvo

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Four star leaded fuel is now almost totally gone from all the petrol station forecourts, and has been replaced by LRP - lead replacement fuel. The lead in the petrol has been replaced with potassium. Some cars can be converted to run on unleaded petrol; some can run on super unleaded petrol instead of leaded four star, and some cannot be converted at all.

Volvo have produced a chart, seen below, that suggests methods of overcoming the problem of conversion. But even some Volvo technicians say that the fitting of a double head gasket is not adviseable. But what other means is available that will make conversion a financial viability. It is no use paying a high price for the conversion if your annual mileage is low.

There are many differing opinions on converting, or the need to convert an engine to run on unleaded fuel. They all come from professional sources, and this suggests there is no tried and tested answer. Some sources say that retarding the ignition timing a few degrees will suffice. Other sources say that hardened valve seats need to be fitted to the cylinder head, others say not. While others will say there is no need to do anything unless you use the car regularly on long journeys at speeds of 60/70 mph.

One of the problems that ocurrs with unleaded fuel is the valve seats over heat and start to burn. All Volvo engines built after the B16, B18 B20, B30 range will have hardened valve seat inserts so these engines will not suffer valve seat erosion, (B21, B23, B200, B230, B27, B28, B280E). But some of these engines have a high compression ratio and need a high octane fuel, and the only way to get them to run on 95 octane unleaded petrol is to fit 2 head gaskets. As mentioned above, this is not a very good idea.

Volvo recommends that its customers use unleaded petrol where at all possible and avoid using unleaded petrol which include replacement additives. Do not use LRP petrol in a turbo engine.

LRP

Regarding LRP and additives, this is an extract from a paper by the Retail Motor Industry Federation:

• The evidence accumulated by the RMI from Sweden shows that engine damage has increased in that country in some vehicles since the introduction of LRP

• Valve burn has increased some 500% since the introduction of LRP, for both hard valve seat engines and soft valve seat engines.

• Corrosion of exhaust valve seats with LRP has ocurred to an extent that prompted the Chairman of the Swedish Engine Overhaulers Association to develop with SKF a high chromium insert which is more corrosion resistant.

• Turbocharger hot corrosion started to ocurr following the launch of LRP

• The turbocharger damage reducing in severity and frequency when sodium anti-wear additive was removed from the market.

• Turbine wheel hot corrosion continues to ocurr with potassium as the only anti-wear additive now marketed albeit to a lesser extent, but failures under warranty continue to occur nearly three years after the withdrawal of sodium.

It is also worth looking at the web site for the Broquet Fuel Catalyst at www.broquet.co.uk

Although it is several years since unleaded fuel was introduced in the UK, many owners of the 120, 1800, 140, 200, 300, 400 and 700 Series Volvo cars still enquire about converting their cars to use unleaded fuel. The following article is based on information from Volvo Car UK, and explains what they consider is necessary.

There is also an interesting web site on 'fuel saving' devices at www.fuelsaving.info

The following is reproduced by courtesy of Volvo Car UK.

The car is a liberating influence on our way of life but it also imposes responsibilities upon drivers and manufacturers. A more respectful attitude towards our environment is now widely regarded as essential. Volvo are conscious of the responsibility we have to both our customers and the environment. We are therefore pleased to announce a new initiative that will assist both. 95 octane* unleaded petrol was introduced into the UK market during 1986 and many drivers are alive to the environmental advantage of using this petrol. The Volvo range has for some years included models that perform efficiently using unleaded petrol with over 50% of the current ½ million Volvos in the UK requiring no adjustment to do so. Your engine's ability to run on 95 octane* unleaded petrol will be dictated by model type, engine variant and model year. It is important to accurately identify the suitability of your engine before attempting to use this fuel. The table should assist you in its identification. However, if you are unsure of the exact details of your model, please contact your local Volvo dealer, who will be pleased to advise you. In March 1989 a high (98) octane unleaded petrol was introduced by a major fuel company. Known as "Super Green," this new fuel effectively means that 100% of Volvo petrol engined cars produced since 1981 model year can use this grade of unleaded petrol without the need of modification.

The model year runs from October to September. The date of purchase or registration suffix letter should be ignored. e.g. A Volvo of model year '85 would have been available from October 1984 to September 1985. Please consult your local dealer if you are unsure of your model year.

SUITABILITY CODE MEANING

1. Can use unleaded fuel after fitting two head gaskets to reduce the compression ratio, and installing deeper water pump seal.

2. Can use unleaded fuel but will cause carburettor metering needle wear. Renew needle every 30,000 miles.

3. Can use unleaded fuel after fitting modified metering needle, part number 3501202-0

• 240 saloon and estate, DL/GL, with B21A 107 HP engine, 1980-83, set ignition timing to 7 degrees BTDC

Q What is the difference between 95 octane unleaded and 98 octane unleaded petrol

A 95 octane unleaded is the standard grade of unleaded petrol introduced in 1986. By the end of the year, 1300 sites will be selling this grade. 98 octane unleaded was introduced in March 1989. It provides the same performance as 4 star leaded petrol currently available but has the considerable advantage of not containing lead. It is sometimes known as "Super Green" and approximately 500 sites will be selling this new grade by the end of the year. It is a few pence more expensive than 95 octane unleaded.

Q Can leaded and unleaded petrol be mixed

A Yes, in engines that have been designed to use either, or have been adapted/modified, unleaded and leaded petrol can be mixed with no detrimental effects. However, the petrol used must meet the octane requirement of your engine.

Q Will the use of 95 octane unleaded petrol affect engine performance and fuel consumption

A This very much depends on the particular engine variant. However, as a rule of thumb, those engines originally designed to accommodate both unleaded or leaded 95 octane petrol, no difference in performance will be noticed. If the engine has been modified or incorporates a device to automatically compensate for the use of 95 octane unleaded petrol a reduction in engine power and increase in fuel consumption may occur. If this is of concern to you, it may be worthwhile considering using 98 octane unleaded, which will not affect your Volvo's current performance.

Q If my engine requires adjustment or modification to run on 95 octane unleaded petrol, what does this entail

A The level of modification depends on model type, year and engine, but ranges from a simple adjustment to the ignition timing, to the relatively major operation of lowering the compression ratio. Your Volvo dealer can provide more information regarding your Volvo.

Q What happens if I use 95 octane unleaded petrol in an engine for which it is not suitable

A A condition commonly known as "pinking" can occur when the engine is under load. If severe and left unresolved, it could lead to engine damage (e.g. to the pistons). Additionally, on older models (prior to those listed in this brochure) damage may be caused to the engine valves and some carburettor parts.

Q What can I do if I incorrectly fill my car with 95 octane unleaded fuel

A If you realise your mistake early enough and only put up to two gallons of unleaded petrol in your tank, you must fill the remainder of the tank with 4 star leaded petrol. If you drive carefully and avoid high engine revs, road speed and engine load, no damage should occur. If, however, "pinking" occurs, consult with your Volvo dealer as soon as possible, as it may be necessary to drain the fuel from your tank. If you put more than two gallons in your tank please consult your nearest Volvo dealer before continuing your journey.

Q Is unleaded petrol available in other countries

A 95 octane unleaded petrol is available in all European countries. 98 octane unleaded petrol is available in some European countries. In a few countries a 92 octane unleaded petrol is also available. This should not be used in UK specification Volvo cars.

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