The difference between petrol and diesel engines
Both petrol and diesel vehicles have internal combustion engines that operate using a two or four-stroke cycle. In addition, the power cycle comprises of four phases: intake, compression, power and exhaust. Though this similarity is apparent, diesel and petrol engines are quite different and each possess advantages and disadvantages.
Owner of Branigans Tyres, and Australian tyre recycler, Chris Lett, unpacks the differences between petrol and diesel engines, and potentially settles the debate about which is the superior engine in a non-competitive manner.
“The main difference between diesel and petrol engines is that a petrol engine has spark plugs, while a diesel engine depends on heavily compressed air,” says Lett. Petrol engines have a compression ratio much lower to that of a diesel engine, as petrol engines use spark plug ignition to ignite the air-fuel mixture. Diesel engines work by compressing only air at such a heavy rate, reaching about 14-23 times its original volume, thus rising the temperature to ignite the diesel fuel.
Lett discusses the advantages of petrol engines. “Petrol vehicles cost much less as opposed to their diesel counterparts, mainly because petrol fuel types are manufactured at lower costs,” says Lett. “Additionally, petrol engines are highly responsive and powerful compared to diesel engines. Petrol engines also run much smoother than diesel engines,” adds Lett. A major disadvantage of petrol engines, however, is that they require more maintenance as they tend to clog up faster. If left unmanaged, petrol engines can deteriorate faster than diesel engines.
“Known as the efficient counterpart to petrol engines, vehicles fitted with diesel engines attain greater mileage, meaning more travel time and less time refuelling. Diesel engines are built to solidly withstand high compressions of gasses with their cylinders, lasting much longer than petrol engines, and requiring less maintenance,” says Lett. Diesel engines are versatile as they can be adjusted to run on alternative and renewable fuels like Bio-diesel. Bio-diesel is used vegetable oil, recycled and intended to potentially power diesel vehicles.
A major disadvantage of the diesel engine is that it produces a particular knocking sound known as diesel clatter, a result of the spontaneous ignition of fuel, causing a pressure wave which makes the engine sound noisier. Another disadvantage is that diesel engines are heavier and not as easy as petrol vehicles to rev, thus making them an undesirable choice for sports cars. More notably, diesel engines are required to be built stronger to hold up against high gas compression, and as such become costly to manufacture, making diesel vehicles more expensive than petrol vehicles.
“All in all, both diesel and petrol engine vehicles present their own uniqueness and capabilities, while carrying the unwanted burdens of imperfection,” says Lett. Conclusively, whether a vehicle owner has a petrol or diesel engine under the bonnet, what matters is how it is maintained, and its operational capabilities.
Branigans Tyres has well-established workshops in Burleigh Heads and Southport in the Gold Coast region. and can service both petrol and diesel engines. Check out their full range of services or current featured promotions. Branigans award-winning affordable tyre subscriptions package start at $7.97 and help motorists budget for their ongoing tyre needs.
Vehicle owners are encouraged to drive in at their convenience as no pre-bookings or appointments are required. Branches are situated at 13 Flagstone Drive, Burleigh Heads, contact number (07) 5535 2660 or 1/277 Southport-Nerang Rd, Southport contact number, (07) 5591 8633.
Syndicated by: YDMA News