Let’s look at various factor about these two engines—Petrol and Diesel, and come up with a conclusion.
Without a doubt, for anybody looking for a fuel-efficient car, Diesel cars are the best option. However with higher car prices, higher fuel costs than petrol cars and the emergence of super-economical petrol engines, are diesel engines still a better choice than petrol engines?
Let’s look at various factor about these two engines—Petrol and Diesel, and come up with a conclusion.
The Price—Car
Diesel cars are currently more expensive than petrol cars. For example a current model Hyundai I30 automatic is around $26000 for a diesel model and around $21000 for a petrol model.
Winner: Petrol
The Price–Fuel
When comes to running costs for fuel, diesel is currently cheaper than petrol in Australia. While a litre of petrol currently costs around $1.40 per litre, diesel costs around $1.25.
Fuel Efficiency
Generally you can expect up to 30% more fuel efficiency from a diesel powered vehicle depending on the way it is driven. However new and emerging technologies are reducing the consumption in petrol engines and we are now seeing fuel efficiency levels between petrol and diesel powered vehicles become much smaller.
Winner: Diesel
The Resale Value
The resale price is generally seen to be better for diesel vehicles, particularly four wheel drive vehicles. The higher purchase price may have something to do with this but also the underlying demand from people looking for a fuel-efficient diesel car. With the cost of buying a new diesel car much higher than a petrol car, good second hand diesel cars will always be in demand.
Winner: Diesel
The Cost of Maintenance.
There is not much difference in the service costs between petrol and diesel powered cars. Using Car Servicing and You’s fixed price log book packages, a 2013 Hyundai I30 petrol has standard service pricing of $1124 for the first 60000 kilometres and the diesel is slightly higher at $1285. Although the costs of maintenance of both types of engine are similar, repairing a diesel engine is way higher than repairing a petrol engine when something goes wrong. Also maintaining a diesel engine over the longer term will require engine and exhaust gas recirculation decarbonising to occur regularly.
Winner: Petrol
The Environment:
In some countries Diesel engines have been incentivised through reduced taxes to encourage the purchase of more fuel efficient vehicles. This has not been the case in Australia. Interestingly, The Mayor of Paris has announced radical plans to ban diesel cars from the French capital by 2020 due to concerns about the fuel’s fumes which contain tiny particles and nitrogen oxides and have been increasingly proven to be seriously damaging to health. London is debating whether to do the same.
Winner: Neither, all petrol and diesel cars are detrimental to the environment and health.
The Power:
Diesel engines offer better torque for lower revs, which is particularly useful when towing or overtaking. Diesel’s do feel less responsive than petrol engines at lower revs which is disconcerting at first if you are not used to driving them.
Winner: Diesel
The Engine noise
Diesel engines generate more noise and vibration across the surface. As a result, the noise inside the cabin of diesel cars is much higher than in petrol cars. Although Diesel engines have evolved over the years, this case is valid for low cost diesel engines.
Winner: Petrol
So which one?
The NRMA have concluded that due to the higher purchase price of diesel models, an analysis of running costs over four years reveals little difference between petrol and diesel. With this in mind consumers’ preference may come down to a vehicle’s engine characteristics and performance.
