1)  Why is Unleaded Gasoline being introduced now?

2)  Why was lead added to gasoline?

3)  When will unleaded gasoline be available in Bahrain?

4)  Will leaded gasoline continue to be supplied in filling stations?

5)  What grades of gasoline will be available in Bahrain?

6)  What is Octane?

7)  What is knocking?

8) Can knocking harm my engine?

9)  What happens if I use the wrong octane gasoline in my vehicle?

10)  What cars can use unleaded gasoline?

11)  How do I know if my car can run on unleaded gasoline?

12)  What octane should I use in my vehicle?

13)  How do I know which grade of gasoline to use?

14)  Does my car need to be modified to run on unleaded gasoline?

15)  Would the unleaded gasoline contain any additive?

16)  Why is the additive being added into Jayyid, but not into Mumtaz?


17) If my car requires high octane leaded gasoline, what should I use?

18) If I have an older car which needs Mumtaz and will require lead replacement additive, when shall I start to use it?

19)  What happens if I accidentally fill unleaded gasoline into a car that cannot
take it?


20)  If after using unleaded gasoline, I have to drive my car in a country where only leaded gasoline is available can the car switch back to leaded gasoline?

21)  What is catalytic converter and does it have to be installed on existing cars?

22)  Can I use gasoline with lead replacement additive for cars fitted with catalytic converter?

23)  Is Unleaded Gasoline suitable for motorcycles, marine outboard engines and jet-skis?

24)  Can vintage and classical cars use unleaded gasoline?

25)  How are Bahrain's car dealers involved?

26)  Will there be any price changes for the unleaded gasoline?

1) Why is Unleaded Gasoline being introduced now?
For many years, lead compounds have been added to gasoline in order to increase the octane rating in the fuel and give better engine performance. However, it has been found that vehicle exhaust emissions containing lead and other pollutants are posing a threat to human health and have long-term harmful effects on the environment.

Removing lead from the gasoline would provide a significant health and environmental benefit to Bahrain. It would also enable the use of advanced emission technologies (catalytic converter) for new cars imported in the future. The introduction is in line with the Government and GCC directives in this respect and is compatible with global trend to harmonize fuel specifications.

2) Why was lead added to gasoline?

Lead compounds were added to the gasoline to increase the octane rating (anti-knock quality) and lubrication between the exhaust valves and the exhaust valve seats in cars with soft valve seats. If the octane rating of the fuel drops below the recommended level specified by cars manufacturers, the car engine may experience knocking (pinking). The unleaded gasoline being introduced in Bahrain would be sufficient for almost all cars in Bahrain.

Also, without the lubrication offered by the lead, the engine's exhaust valves in older cars with soft valve seats, may start to wear out, depending on the driving condition. This would occur when driving at high speed with load for extended periods. Lead replacement additive would be available in the unleaded Jayyid gasoline. This additive would also be available as an "after-market" product sold in bottles at the service stations, for the unleaded Mumtaz gasoline users.


3) When will unleaded gasoline be available in Bahrain?
Unleaded gasoline will be produced for the local market starting July 2000. The new unleaded gasoline would gradually replace the leaded gasoline currently in local market. The concentration of leaded gasoline will gradually diminish in the

storage tanks at the service stations. It is expected that the unleaded gasoline would completely phase out the leaded gasoline by the end of the year 2000. Bapco intends to conduct series of tests to monitor and assess the contents of the tanks to establish when they will contain fully unleaded gasoline. Should the unleaded gasoline specification achieved earlier, this will be announced accordingly by Bapco.

4) Will leaded gasoline continue to be supplied in filling stations?
No, leaded gasoline will not be produced for the local Market in Bahrain as of early July 2000.
5) What grades of gasoline will be available in Bahrain?
Two unleaded grades, Mumtaz and Jayyid - will be produced for the local market in Bahrain as from early July 2000.

The new Jayyid will be 91 Research Octane Number (RON), while Mumtaz will be 95 RON. (Previously, Jayyid was 90 RON and Mumtaz was 98 RON.) Almost all vehicles using the current leaded Mumtaz will be suitable to use the unleaded 95 RON Mumtaz.
6) What is Octane?
Research Octane Number (RON) and Motor Octane Number (MON) are measures of fuel anti-knocking performance. Minimum octane limits are specified by vehicle manufacturers to avoid knocking, which, in severe cases, may lead to power loss and engine damage. The octane requirement to avoid knocking is related to the engine type and engine operating conditions.
7) What is knocking?
Spark knock is the sound of abnormal fuel combustion. When a spark initiates combustion in a spark-ignition internal combustion engine, the flame front should fan out from the spark plug and travel across the combustion chamber rapidly and smoothly. If the last part of the air-fuel mixture ignites spontaneously (auto-ignites) before the flame front arrives, the sudden jump in the pressure in the cylinder creates the characteristic knocking or pinking sound. Knocking occurs because the octane of the fuel is below the antiknock requirement of the engine at that moment.
8) Can knocking harm my engine?
Occasional light knocking will not harm an engine. Heavy or prolonged knocking can result in loss of power, overheating of parts in the cylinder, and may end up causing engine damage.
9) What happens if I use the wrong octane gasoline in my vehicle?
Using gasoline with lower octane RON than that required by your vehicle will cause the engine to knock or, if the engine is equipped with a knock sensor, decrease the vehicle's power and acceleration. Using a gasoline with a RON higher than that required by your vehicle is unnecessary and a waste of money.
10) What cars can use unleaded gasoline?
All modern cars are suitable for unleaded gasoline except for some older cars. We have listed within this site, information on all car models that are suitable for unleaded gasoline.
11) How do I know if my car can run on unleaded gasoline?
First consult your vehicle's Owner Manual and the list which is outlined in this site. If, after doing this, you are still unsure whether your car could use unleaded gasoline, seek advice from your local vehicle dealer.
12) What octane should I use in my vehicle?
Use a gasoline with the RON recommended by your vehicle manufacturer (refer to your vehicle's Owner's Manual). Using gasoline with a RON higher than that required to prevent knock will not improve a vehicle's performance or its power.

In many modern vehicles, the driver may never hear knocking when the RON of the gasoline is lower than the octane requirement of the engine because the engine is equipped with a knock sensor which temporarily retards spark timing to prevent knock. This adjustment may result in loss of power and acceleration. In this case, switching to a gasoline with a higher RON will improve performance and increase power.
13) How do I know which grade of gasoline to use?
You should refer to your vehicle Owner's Manual or check with the vehicle dealer.

Please note:
American carmakers have a different system of indicating octane requirement please refer to your vehicle dealer for clarification.
14) Does my car need to be modified to run on unleaded gasoline?
Modern cars are designed to run on unleaded gasoline. Some old cars fitted with soft exhaust valve seats, require lubricity offered by the leaded gasoline. Lead replacement additive would be added to the Jayyid gasoline, thus it would provide the necessary lubricity for the cars that need it. For the cars that have soft exhaust valves and need to use the higher octane offered by Mumtaz, the lead replacement additive would be available as an "after-market" product and sold in bottles at service stations.

Hence, in both cases, no adjustment is required. However, if your car's engine starts knocking (pinking) for prolonged period after the use of the new fuel, please refer to your car dealer, as your car may need minor adjustment of the engine sparks timing to prevent the knocking.
15) Would the unleaded gasoline contain any additive?
Bapco will add lead replacement additives to all unleaded Jayyid gasoline. So the new Jayyid fuel will contain additives that will protect against valve seat recession in older vehicles.
16) Why is the additive being added into Jayyid, but not into Mumtaz?
Although only a small number of old cars would need such an additive, the additive is being added to all Jayyid unleaded gasoline for the Local Market. However most of these old cars use Jayyid gasoline. Only a very small number of older high-performance cars may require Mumtaz with additives. For those vehicles, the additives will be available as an "after-market' product available in bottles at service stations.
17) If my car requires high octane leaded gasoline, what should I use?
If your car requires the high octane of Mumtaz Gasoline, you should continue to use unleaded Mumtaz gasoline and buy the lead replacement additive which will be made available in bottles at the service stations.
18) If I have an older car which needs Mumtaz and will require lead replacement additive, when shall I start to use it?
The concentration of lead in the service stations tanks will decrease gradually throughout July and August this year, therefore if you need to add the lead replacement additive we would we recommend you start using it from early August 2000.
19) What happens if I accidentally fill unleaded gasoline into a car that cannot take it?
If you have used unleaded Jayyid gasoline, then there is nothing to worry about, as the additive already added to the Jayyid would provide the necessary protection.

If you have used the unleaded Mumtaz without adding any lead replacement additive, do not panic, as the valve seat recession would only occur in older engines under sustained speed and load.
20) If after using unleaded gasoline, I have to drive my car in a country where only leaded gasoline is available can the car switch back to leaded gasoline?
Yes, there are generally no problems in mixing the two types of gasoline, provided that your car is not fitted with a catalytic converter.

21) What is catalytic converter and does it have to be installed on existing cars?
A catalytic converter is a filtration device that work to eliminate harmful gases from car's exhaust emissions. It is usually installed on new cars and linked to their fuel injection system to maintain optimum operation and control exhaust emissions. Catalytic converters are not generally retrofitted on existing cars.

Most modern cars using leaded gasoline could safely use unleaded gasoline with no modifications required. It is not necessary for a car to be equipped with a catalytic converter to use unleaded gasoline. However, cars equipped with catalytic converters should not use leaded gasoline, as lead would affect the converter's ability to perform its intended function.
22) Can I use gasoline with lead replacement additive for cars fitted with catalytic converter?
Using Jayyid with lead replacement additive or Mumtaz with the same additive (in bottles) is not recommended with catalytic converter.

23) Is Unleaded Gasoline suitable for motorcycles, marine outboard engines and jet-skis?
Unleaded gasoline is generally suitable for most motorcycles, marine outboard engines or jet-skis, except for a few which are equipped with older types of engines. Please refer to your equipment dealer for more information.
24) Can vintage and classical cars use unleaded gasoline?
Antique cars are typically exposed to such light service that they are not expected to have valve seat problems. Thus using unleaded gasoline is not a problem. The customer will always have a choice of using lead replacement additives to provide the necessary protection either in bottles or by simply using the unleaded Jayyid with the additives already added to it.
25) How are Bahrain's car dealers involved?
Bapco has had meetings with the local car, motorcycles, marine outboard engine and jet skis dealers in Bahrain who are being fully co-operative with the planned introduction and are prepared to supply their customers with the information needed to ensure that the introduction to using unleaded is as smooth as possible.
26) Will there be any price changes for the unleaded gasoline?
Although the investment and running cost of producing unleaded gasoline would be at a considerable cost to Bapco, the Government has decided keep the present prices unchanged.