LPG vs Propane: Understanding the Difference
Walk into any hardware store or talk to a gas supplier, and you'll hear the terms LPG and propane used almost interchangeably. But are they truly the same thing? The short answer is: not quite. Understanding the distinction helps you make better decisions about fuel storage, appliance compatibility, and cost efficiency.
What Is LPG?
LPG (Liquefied Petroleum Gas) is a broad category of hydrocarbon gases that are liquefied under moderate pressure for storage and transport. It is primarily composed of:
- Propane (C₃H₈) — the most common component in many regions
- Butane (C₄H₁₀) — often mixed in depending on the supplier and season
- Isobutane — occasionally present in smaller quantities
The exact composition of LPG varies by country, climate, and supplier. In colder climates, LPG tends to be higher in propane content because butane doesn't vaporize well at low temperatures.
What Is Propane?
Propane is a specific, single-compound gas (C₃H₈). When you purchase "propane" from a supplier — especially in North America — you're getting a product that is at least 90% pure propane. This makes it a more consistent and predictable fuel source.
Key Differences at a Glance
| Feature | LPG (Blended) | Propane (Pure) |
|---|---|---|
| Composition | Propane + Butane mix | Predominantly propane |
| Boiling Point | Varies with mix ratio | −42°C (−44°F) |
| Cold Weather Performance | Can underperform in cold | Reliable in cold climates |
| Energy Content | Slightly lower (with butane) | ~25.3 MJ/litre |
| Availability | Widely available globally | Dominant in North America |
| Common Use | Cooking, heating, vehicles | BBQs, heating, industrial |
Which Is Better for Cold Weather?
If you live in a region with cold winters, this distinction matters a great deal. Butane stops vaporizing at around 0°C (32°F), meaning a butane-heavy LPG blend may fail to provide adequate pressure on cold days. Propane, by contrast, vaporizes effectively down to −42°C, making it the clear winner for outdoor applications, off-grid heating, and winter camping.
Appliance Compatibility
Most modern gas appliances designed for LPG will work with either propane or a propane-butane blend, but always check the manufacturer's specifications. Key considerations include:
- Regulator pressure settings — propane typically operates at higher pressure than butane blends
- Jet/nozzle sizing — some appliances require different orifice sizes for propane vs butane
- Safety certifications — appliances are often certified for a specific gas type
Cost Considerations
Pricing varies by region and supplier, but generally:
- Butane-blended LPG is often cheaper per unit volume
- Propane delivers more usable energy per litre in cold conditions
- In regions where pure propane is standard, pricing is straightforward
Always compare cost on an energy-per-dollar basis rather than just volume, since energy content varies between blends.
The Bottom Line
If you're in North America using a standard BBQ or home heater, you're almost certainly using propane and don't need to worry about blends. If you're elsewhere in the world using "LPG," the mix you receive depends on your supplier and local conditions. When in doubt, ask your supplier for the exact composition — especially if you're running sensitive industrial equipment or working in cold environments.