LPG (Liquefied Petroleum Gas) tends to slightly reduce a vehicle’s performance, but under normal driving conditions, the difference is hardly noticeable. The only time you might experience a noticeable drop in performance is during fast driving, when carrying heavy loads, or when high performance is required. However, most drivers don’t encounter these situations frequently, so the slight performance reduction is often not an issue.
Why Larger Engines Handle LPG Better
Many people who convert from petrol to LPG do so to cut down on fuel costs, especially those with larger engines. Larger engines tend to mask the minor performance drop because they already deliver more power than smaller engines. The performance impact is less noticeable in bigger vehicles as they typically have higher horsepower and torque compared to smaller cars.
LPG conversions are especially popular among vehicles with larger engines like SUVs and trucks, where fuel consumption can be higher. These vehicle owners often prioritise savings at the pump, and the slight decrease in performance is outweighed by the significant reduction in fuel costs.
Cooler Burning Fuel
LPG is a cooler burning fuel, which means the engine produces less heat and pressure in the cylinders. Because of this, LPG has less “power” per combustion charge compared to petrol. As a result, drivers may instinctively press harder on the accelerator to compensate for the reduced power. However, doing this increases fuel consumption. To maximise the efficiency of LPG, it’s important to accelerate steadily and allow the vehicle to naturally build speed, rather than over-accelerating.
Failing to do so can result in more frequent stops at the pump—around 15% more refuelling than with petrol. Despite this, LPG still offers significant cost savings, as it tends to be about half the price of petrol and more than half the cost of diesel. The savings are particularly noticeable for high-mileage drivers, such as those in the delivery or rideshare industry.
Temperature and LPG Combustion
One of the unique aspects of LPG is that it turns into gas vapour at normal atmospheric temperature. In the engine’s hotter environment, LPG evaporates quickly. While LPG burns cooler than petrol, the rapid evaporation inside the engine can cause the cylinder head temperature to rise. This increase in temperature is something to monitor, especially as not all vehicles have a built-in cylinder head temperature gauge.
Due to the increased temperature in the cylinder head, it’s essential to ensure proper cooling of the engine when running on LPG. Regular maintenance, including checking coolant levels and ensuring that cooling systems are in good working order, is vital for preventing potential overheating issues. Drivers who regularly operate their vehicles in hotter climates or under heavy loads should pay extra attention to the vehicle’s cooling system.
Faster Engine Warm-up
An interesting benefit of LPG is that it causes the engine to heat up faster, even when the engine is cold. Petrol engines, by contrast, take longer to warm up. The faster warm-up time can be seen as a positive for engine performance, especially in colder weather. Additionally, LPG is a high-octane fuel and burns much cleaner than petrol. Drivers will notice fewer engine knocks, sputters, and carbon deposits with LPG. This cleaner combustion process results in less wear and tear on the engine, potentially extending the engine’s lifespan over time.
While faster warm-up times can benefit vehicles in colder climates, it’s still essential to let the engine run for a few minutes before driving, particularly in the winter months. This ensures the vehicle is ready to perform optimally without straining the engine from a cold start.
Condensation and Icing Issues
Ironically, while LPG’s rapid evaporation can cause the cylinder head to heat up, it can also lead to excessive condensation and icing on the regulator. This is another reason why it’s important not to accelerate too quickly when using LPG, as rapid acceleration exacerbates these conditions. Steady driving will help reduce condensation and prevent icing, ensuring the vehicle runs more smoothly.
Condensation and icing can lead to reduced fuel efficiency and performance. It’s a good idea to regularly inspect the LPG system for signs of wear or damage. Keeping the system well-maintained will help avoid issues such as icing or blockages in the regulator.
Conclusion
While LPG can slightly reduce a vehicle’s performance, the impact is minimal under normal driving conditions. Larger engines tend to handle the conversion better, and the fuel savings from LPG often outweigh any performance drawbacks. To get the best out of an LPG-powered vehicle, drivers should accelerate gradually and avoid overworking the engine. Regular maintenance is also crucial to keeping the system running efficiently.
LPG’s cleaner burn, high octane, and cost benefits make it an attractive option for many drivers looking to cut fuel costs while maintaining good vehicle performance. With proper care and steady driving habits, LPG can offer substantial long-term savings without sacrificing too much on the performance front.
