Buying a used car is a big decision, and one of the most common questions drivers ask is whether they should choose petrol or diesel. Both fuel types have strengths and limitations, and deciding between them depends on how you drive, the distances you cover and what you want from your vehicle in the long term. Making the right choice will help you save on running costs and enjoy your car for years to come.
At Perth Auto Centre, we talk with buyers every week who face this question. Whether you’re cruising around the city, driving up to the hills or planning regular highway trips, understanding the differences between petrol and diesel cars will help you make a confident decision.
Petrol cars use spark-ignition engines that burn petrol mixed with air to create power. These engines are the most common type found in everyday cars — from smaller hatchbacks to medium SUVs. Petrol engines are known for their smooth performance and ease of use in city environments.
If most of your driving is around town, short errands, school runs or commuting through peak traffic, petrol cars are often the easier and more cost-effective choice.
Diesel cars use compression-ignition engines that burn diesel fuel. These engines produce more torque at lower RPMs, which gives them strength and efficiency — especially when carrying heavier loads or travelling long distances. Diesel engines are typically found in larger SUVs, utes and vehicles used for towing.
Diesel cars are often chosen by drivers who cover a lot of highway kilometres, tow trailers or campers, or need a vehicle that feels confident under heavier loads.
When choosing between petrol and diesel, it’s important to think about more than just the price per litre at the pump. Running costs include fuel usage, servicing, insurance and long-term maintenance.
If you do mostly short drives within the city, petrol cars typically cost less overall because diesel’s fuel advantages are not fully realised on short trips. Conversely, if you regularly travel long distances or tow loads, diesel’s better fuel economy can outweigh its higher servicing costs.
Another key difference between petrol and diesel is how the engine feels and performs. Petrol engines feel lighter and more responsive at lower speeds, which can make driving in town or traffic easier and more enjoyable. Diesel engines deliver stronger torque at lower revs, which translates into better pulling power for overtaking, towing or carrying extra weight.
Simple everyday comfort and responsiveness are often better in petrol vehicles for city drivers. Diesel engines, on the other hand, feel more capable and stable at highway speeds or under load.
Both petrol and diesel engines produce emissions, but their profiles differ. Petrol engines typically emit higher carbon dioxide (CO₂), while older diesel engines can emit higher levels of nitrogen oxides (NOₓ) and particulates. Modern engines from both fuel types now include improved emission controls, making them significantly cleaner than older models.
If environmental impact is important to you, consider engine age, emission standards and technology rather than fuel type alone. Newer engines with advanced emission control systems are cleaner and more efficient regardless of whether they run on petrol or diesel.
There is no single right answer, but the following guidelines can help:
Understanding your average weekly kilometres and driving conditions is key to making the right choice that will suit your lifestyle and budget.
Choosing between petrol and diesel requires weighing up your driving needs, budget and how you use your car. Both fuel types have their strengths — petrol for city and light use, diesel for long distances and heavy loads. With the right information, you’ll be able to make a choice that you’re happy with for years to come.
Ready to explore quality petrol and diesel used cars in Perth? Browse the current range at Perth Auto Centre and take the next step with confidence.
