This is among the most commonly debated questions among motoristsActually the truth is there is no straight forward answer to this question, merleyopposing arguments which will suit depending on your priorities.
Both petrol and diesel engines emit pollutants which are widely accepted to damage air quality and the environment. Vehicle manufacturers have made substantial improvements to reducing emissions over recent years. This has been, driven by increasing awareness from consumers on the environmental impact their motoring causes and EU legislation which has demanded a reduction in Co2 emissions from the internal combustion engine. Amazing advances in engine management systems and emissions filtration have seen both diesel and petrol engines emitting less and less Co2. Consumers benefit from this with an increasing large array of vehicles to choose from with free or low road tax costs as well as being secure in the knowledge that the latest engine technology will ensure they are filling up at the pumps as infrequently as possible
Historically diesel was cheaper than petrol which combined with economy benefits over the petrol engine meant for a lot of drivers diesel was their first choice. www.dummies.com estimates that diesels, ‘typically deliver 25 to 30 percent better fuel economy than similarly performing petrol engines.’ However diesel is now more expensive than petrol at the pumps so the economy benefit needs to be weighed against increased fuel costs and this has made the debate less straight forward.
Both petrol and diesel engines can offer excellent economy low emissions and a great driving experience. What can be a factor in differentiating between petrol or diesel for many consumers is the type of driving they do. There is little doubt that for high mileage, long distance driving diesel will deliver economy benefits compared to the petrol engine. The technological advances which have seen huge advances in economy and emissions do need to be looked at when making a purchase decision. Many manufacturers are now requesting, during pre-sales qualification, that customers drive their diesel car for a minimum distance each month. The idea of a diesel appeals to many however short local journeys do not give the advanced regenerative filtration systems built in to modern diesel cars adequate time to work effectively. This type of driving in a modern diesel engine can lead to expensive repairs which can easily wipe out any fuel consumption benefits.
For those use their car for shorter urban journeys petrol engines currently offer a solution which avoids the requirements for regular long journeys demanded by some diesel engines and their advanced particulate filtration systems.
Petrol or diesel used to be the straight forward choice consumers faced when choosing a car, however we are now seeing a variety or petrol and diesel hybrid engines which combine electric motors with the internal combustion engine to deliver further benefits in economy and emissions. This hybrid technology is becoming more widely available and it will be interesting to see how long it takes before the majority of cars are driven, at least in part, by electric power.