Choosing the right type of engine is becoming more complicated every year: fuel prices keep changing, electric vehicles are gradually becoming more affordable, and LPG systems fluctuate in cost and availability. To answer which fuel type is the most cost-effective for you personally (for example, diesel or petrol), it’s important to compare all four options using the same criteria — without marketing bias or unnecessary emotion.
What criteria are used to compare different types of car engines
An objective comparison is based on five key parameters:
- Fuel/energy cost per 100 km of driving
- Maintenance costs – service frequency and expense
- Engine lifespan – average mileage before major overhaul
- Entry cost – purchase price of the vehicle or conversion costs
- Ease of use – fuel availability, charging time, and urban restrictions
No engine type wins across all categories at once — everything depends on usage conditions and the owner’s priorities. For example, when choosing between diesel and petrol, diesel is usually more cost-effective in terms of fuel consumption, while petrol tends to be cheaper to maintain. Likewise, when comparing electric and petrol vehicles, it’s important to consider your actual electricity tariffs rather than relying on generalized figures from articles.
Diesel cars: key advantages and fuel consumption
Diesel is a traditional choice for high mileage and commercial transport. Fuel consumption for passenger cars is around 5–7 L/100 km, for SUVs 7–9 L/100 km, and for off-road vehicles it can exceed 15 L/100 km. A diesel engine is 20–30% more fuel-efficient than a petrol one and delivers higher torque — especially important under load.
Advantages: low fuel consumption, long engine lifespan (300,000–500,000 km), excellent low-end torque.
Disadvantages: higher maintenance costs (fuel system components, diesel particulate filter DPF), restrictions in low-emission zones in European cities, sensitivity to fuel quality, and more difficult or historically limited LPG conversion options.
Beneficial for: high annual mileage (from 30,000 km), long-distance trips, trucks and commercial vehicles.
Petrol cars: key advantages and fuel consumption
A petrol engine is the most widespread and easiest to maintain. Average fuel consumption for a passenger car is 7–10 L/100 km, while small city cars can use around 5–6 L/100 km. Maintenance costs are lower than for diesel engines, and the choice of models on the market is the widest.
Advantages: affordable vehicle price, simple and inexpensive servicing, reliable operation in all temperatures, and the potential for future LPG conversion.
Disadvantages: higher fuel consumption compared to diesel engines, and lower efficiency in city driving conditions.
Best suited for: moderate annual mileage (up to 20,000 km), urban driving, and for those who value simplicity and low-cost maintenance.
Gas-powered cars: key advantages and fuel consumption
LPG (liquefied petroleum gas) systems are the most budget-friendly option in terms of fuel cost. Propane-butane (LPG) is roughly twice as cheap as petrol, although gas consumption is about 10–15% higher. In practice, this results in real fuel savings of around 40–50% compared to petrol. From a fuel cost perspective, the question “gas or petrol” almost always has the same answer — gas. The cost of installing an LPG system ranges from €500 to €1,500, depending on the system type.
Advantages: significant fuel savings, dual-fuel operation (gas + petrol) for added flexibility, and lower engine wear due to cleaner combustion.
Disadvantages: reduced boot space due to the gas tank, the need to plan routes based on LPG station availability, and additional installation and certification costs required by authorities.
Best suited for: petrol car owners driving over 20,000 km per year, where the LPG system typically pays for itself within 1–2 years.
Electric vehicles: key advantages and energy consumption
An electric car is the cheapest option in daily operation, but also the most expensive at the point of purchase. Average energy consumption is 15–20 kWh/100 km. With home charging, the “refuelling” cost is several times lower than petrol. Maintenance is minimal: no engine oil, no ICE filters, no clutch, and no exhaust system.
Advantages: the lowest cost per 100 km, minimal maintenance expenses, zero emissions — no restrictions in city zones.
Disadvantages: high initial purchase price, dependence on charging infrastructure, reduced range in winter conditions, and potential battery replacement costs after 8–10 years.
Best suited for: city drivers with access to home charging, daily mileage up to 100–150 km, and those planning to keep the vehicle for 5+ years.
On Autoline, you can find a wide selection of listings for vehicles with any type of engine — from diesel trucks to electric cars — offered by verified sellers from around the world.
Comparison table
Criteria | Diesel | Petrol | LPG | Electric |
Fuel consumption | 5–9 L/100 km | 6–10 L/100 km | 8–11 L/100 km | 15–20 kWh |
Cost per 100 km | average | higher | lowest | lowest |
Maintenance costs | expensive | affordable | moderate | minimal |
Engine lifespan | 300–500k km | 200–350k km | 200–350k km | 500+k km |
Vehicle purchase price | average | low | low + LPG | high |
Refuelling convenience | high | high | moderate | depends on the city |
Environmental impact | low | low | moderate | high |
There is no single definitive answer to the question “which is better — petrol or diesel, gas or electric.” Diesel makes sense for high mileage, petrol is a versatile and simple option, LPG offers the fastest payback, and electric cars are the most cost-efficient in the long run — provided there is adequate charging infrastructure. The key is to assess your actual driving needs and usage conditions — that is where the real answer lies.