There was once upon a time when diesel was the king of getting you somewhere cheap. Prices were lower, engines consumed less over long distances. The black smog of the diesel engine was the choice of the man chained to the carriageway.
In the last twenty years, it seems that the difference between petrol and diesel engines has become a thin margin. Petrol always equalled performance. Diesel was equal to efficiency. Improvements in technology and price changes in the fuel market have virtually leveled the playing field.
So, what was the difference, is the now difference and what does the future hold?
Petrol vs Diesel
The price difference between the two came down to the refining process. Diesel is easier to produce than petrol, although it is left with much more pollutants than petrol. This leaves extra work for the car manufacturers if they’re to meet todays strict regulations for emissions.
Diesel contains more energy than petrol, which gives it the edge on efficiency. A diesel engine can produce as much as 40% more work than a petrol engine for the same capacity of fuel. Although, this all comes at the cost of more harmful fumes being released into the atmosphere.
It is the highly refined petrol that has always had lead when it comes to performance. Whilst diesel may produce a higher torque, it does so at a lower RPM. Petrol is highly combustible, so when it comes to 0-100, it flies out of the traps to take the lead.
The combustion of the two liquids are two different processes. Diesel relies on compression and heat plugs to ignite the fuel whilst the more volatile petrol takes just a spark.
Over time the manufacturers have developed much higher performing diesel engines, meaning that between say the VW Golf GTI and PTDI there is not so much difference when it comes to the 0-100. This does rely on burning more diesel though, so all those savings in fuel have also gone out the window, leaving not much in the way of a toss-up aside from emissions.
As for the future, it seems the lowly diesel engine will probably be the first to fall victim to the electric motor. With hybrid vehicles already opting for petrol engines, it’s likely diesel has almost seen its day.
There’s no doubt that petrol won’t be far behind. With some electric vehicles now pushing to outperform their fossil fueled forefathers, a new dawn is certainly on the horizon.