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Chapter 1: Fuel Dispensing Operations3 Topics1 Quiz
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Chapter 2: Basic Vehicle Maintenance Checks3 Topics1 Quiz
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Chapter 3: Forecourt Housekeeping3 Topics1 Quiz
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Chapter 4: Receiving Stock2 Topics1 Quiz
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Chapter 5: Recording Transactions and Processing Payments4 Topics1 Quiz
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Chapter 6: Interact with Customers4 Topics1 Quiz
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Chapter 7: Shift Procedures and Reporting4 Topics1 Quiz
Topic 2: Fuel Identification (ULP vs Diesel)
Nolubabalo Ngwanya May 4, 2026
By the end of this topic you will be able to:
- Identify the different types of fuel available at a South African petrol station.
- Distinguish between ULP 93, ULP 95 and Diesel by their properties and uses.
- Explain the consequences of misfuelling a vehicle.
- Follow the correct procedure when a customer is unsure which fuel their vehicle requires.
Overview of Fuel Types
South African petrol stations typically stock three main types of vehicle fuel. As a petrol attendant it is critical that you know the difference between them — putting the wrong fuel into a vehicle can cause severe and costly engine damage.
| Fuel Type | Octane / Grade | Typical Use | Nozzle Colour (SA standard) |
|---|---|---|---|
| ULP 93 | 93 RON | Standard petrol engines (inland areas) | Green / Yellow |
| ULP 95 | 95 RON | Higher-performance petrol engines (coastal areas or performance vehicles) | Green / Yellow (label differs) |
| Diesel | Compression ignition | Diesel engines (trucks, 4×4s, many modern passenger cars) | Black / Yellow |
ULP 93 vs ULP 95 — What Is the Difference?
ULP stands for Unleaded Petrol. The number refers to the octane rating (RON — Research Octane Number), which measures the fuel’s ability to resist “knocking” (premature combustion) in the engine.
- ULP 93 is used at higher altitudes (Gauteng and inland provinces) where the air is thinner and less compression is needed.
- ULP 95 is used at coastal areas (Western Cape, KwaZulu-Natal) where denser air means engines need higher-octane fuel to avoid knocking.
- Using ULP 95 in a car designed for ULP 93 will not harm the engine but will cost more. Using ULP 93 in a high-performance car that requires 95 can cause knocking over time.
- When in doubt, always ask the customer which grade they require — never assume.
Identifying Diesel Vehicles
Diesel vehicles are common on South African roads. As an attendant you need to identify them quickly:
- Check the fuel cap label — most vehicles have “DIESEL” or a pump icon printed near the fuel cap.
- Check the dashboard (if visible) — diesel vehicles often have a “D” or “TDi/CDi/HDi” badge.
- Check the vehicle badge on the rear — e.g., “2.0 TDi”, “D4D”, “CDI”, “HDi”.
- When uncertain, always ask the driver: “Is your vehicle petrol or diesel?”
Misfuelling — Consequences and Prevention
Misfuelling — putting the wrong fuel into a vehicle — can cause catastrophic engine damage and is a major safety risk. A petrol attendant who misfuels a vehicle may be held personally liable.
| Misfuel Scenario | Immediate Effect | Long-term Risk |
|---|---|---|
| Petrol into a diesel engine | Engine may run rough or stall | Severe fuel system and injector damage — costly repair |
| Diesel into a petrol engine | Engine may misfire or not start | Spark plug fouling; catalytic converter damage |
| ULP 93 in a 95-required engine | May cause knocking under load | Long-term engine wear if repeated |
Procedure When a Customer Is Unsure
- Politely ask the customer: “Good day, is your vehicle petrol or diesel?”
- Ask for the grade: “Will that be 93 or 95 Unleaded?”
- Check the fuel cap area for labels or stickers confirming the fuel type.
- If still uncertain, do not fuel the vehicle — call your supervisor immediately.
- Never guess or assume based on the vehicle make alone.
Fuel Properties at a Glance
| Property | ULP (Petrol) | Diesel |
|---|---|---|
| Colour | Clear / pale yellow | Pale green / amber |
| Smell | Sharp, solvent-like | Oily, heavier odour |
| Ignition type | Spark ignition | Compression ignition |
| Flammability | Highly flammable | Less volatile than petrol |
| Energy density | Lower | Higher (better fuel economy) |
Key Terms
| Term | Definition |
|---|---|
| ULP | Unleaded Petrol — petrol fuel with no added tetraethyl lead. |
| RON | Research Octane Number — a measure of fuel’s resistance to knocking; higher = more resistant. |
| Diesel | A heavier petroleum fuel used in compression ignition engines. |
| Misfuelling | Putting the wrong type of fuel into a vehicle’s tank. |
| Knocking | Premature ignition of fuel in a petrol engine, causing a characteristic “knocking” sound and engine damage. |
Before moving to the next topic, ask yourself:
- What does ULP stand for, and what does the number (93 or 95) represent?
- What should you do if a customer does not know whether their vehicle is petrol or diesel?
- Name one consequence of putting petrol into a diesel engine.
Review the tables above if you are unsure of any answers.
📚 Additional Resources
📖 Further Reading
🎬 Watch: Petrol vs Diesel – Know the Difference
This video explains the key differences between petrol and diesel, helping you identify and dispense the correct fuel every time.
📊 Chapter 1 Presentation
Review the full Chapter 1 slide deck used in this module:
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