Planning a road trip? Learn how to read petrol pump labels and select the right fuel types in Vietnam to protect your rental vehicle’s engine.

Spotting the Roman Numerals – Deciphering Petrol Pumps on a Vietnam Road Trip

Embarking on a road trip across Vietnam offers unparalleled freedom, from navigating coastal highways to climbing misty northern passes. However, pulling into a local petrol station can quickly turn into a confusing experience. Unlike Western stations that simply offer “Regular” or “Premium,” Vietnamese fuel pumps feature an array of acronyms and Roman numerals. Understanding the different fuel types in Vietnam is critical to keeping your rental vehicle running smoothly and avoiding costly mechanical damage along the way.

Understanding the Octane Ratings: RON 92 vs. RON 95

When you pull up to a station, the first thing you will notice are the numbers 92 and 95. These refer to the Research Octane Number (RON), which measures the fuel’s resistance to engine knocking.

E5 RON 92: The Eco-Friendly Budget Choice

E5 RON 92 is an ethanol-blended biofuel containing 95% mineral gasoline and 5% bio-ethanol. It is the most affordable and widely available option across the country. While it is perfectly suitable for standard, low-compression city scooters like the Honda Wave or older motorbikes, it is generally not recommended for modern cars or high-performance vehicles.

RON 95: The Standard for Modern Performance

If you are renting a modern sedan, an SUV, or a large-displacement touring motorcycle, you should strictly opt for RON 95. High-compression engines require this higher octane rating to prevent improper combustion, optimize fuel efficiency, and ensure responsive acceleration on steep mountain inclines.

The Secret Behind the Roman Numerals: Tiers III vs. V

The biggest point of confusion for travelers is seeing multiple variations of RON 95 side-by-side, explicitly labeled with Roman numerals like “III” or “V”. These numerals indicate the environmental emission tier of the fuel, which directly correlates to the chemical purity of the gasoline.

RON 95-III (Euro 3 Standard)

This version meets older Euro 3 emission requirements. While it is still widely circulated, it contains higher levels of sulfur, benzene, and aromatics compared to its premium counterpart.

RON 95-V (Euro 5 Standard)

As Vietnam continues its aggressive transition toward cleaner energy and stricter urban emission standards, major distributors like Petrolimex have rolled out fuel types in Vietnam that meet the stringent Euro 5 classification. Labeled as RON 95-V, this ultra-clean premium gasoline features a heavily reduced sulfur content.

Using lower-tier fuel in a modern vehicle designed for Euro 5 standards can trigger engine warning lights, clog fuel injectors, and damage sensitive oxygen sensors. If you are behind the wheel of a newer car model, prioritizing RON 95-V will safeguard your engine’s longevity.

Essential Tips for the Road

To ensure a seamless journey, secure a reliable vehicle from a trusted marketplace like VietWheels. When pulling up to the pump, stick to reputable, well-lit national chains like Petrolimex or PV Oil to avoid the risk of diluted or contaminated fuels occasionally found at unbranded rural stations. When instructing the attendant, you can simply use the phrase “Xăng chín-mươi-lăm đầy” to request a full tank of premium 95.

Have you ever encountered a confusing fuel pump while driving abroad, or do you have a survival tip from your own Vietnamese road trip? Drop a comment below and share your experiences with fellow travelers!