ALT-3 What are the Differences between Diesel and Gasoline Engines
We are going to approach this discussion from the standpoint of all the benefits of a Diesel engine as opposed to a Gasoline power point, rather than a detailed dissection of the inner workings of the two different engines. A consumer can make an informed choice between the two engines if the benefits are clear; it's not essential to know exactly how each engine is constructed.
(1) Purchase Cost
A Diesel engined car will cost substantially more than its Gasoline opposite number due to its more complex construction but there are numerous long term benefits for the driver who is prepared to wait and who travels a high mileage each year.
(2) Longevity
Due to superior design attributes, which providing the engine is maintained meticulously, a diesel engine will far outlive a gasoline equivalent, meaning much less expenditure on major internal repairs. The reliability of the Diesel power train can mean substantially less down time in the garage which is a cause for considerable concern with the Gasoline engine particularly for busy people who spend much of their working lives clocking up high mileage behind the wheel.
(3) Fuel Efficiency
Cost of fuel used to be much less for the Diesel owner but this has evened out in the last several years with oil shortages giving rise to wildly fluctuating prices at the pumps, making it rather difficult to assess comparisons with Gasoline. Diesel engines, however, are very much more fuel efficient and high mileage drivers see a substantial saving when comparing the miles per gallon achieved between the two types of power unit.
It is not at all unusual for the Diesel owner to produce consumption figures of over 60 miles per gallon or more, compared with a gasoline average of 40 miles per gallon for similar sized cars. Of course driving style and urban or rural terrain will play a big part in the overall consumption figures. A heavy footed driver who persistently uses hard acceleration wherever he or she may be will burn and waste a large quantity of fuel whichever engine is chosen.
(4) Performance
In by gone days Diesels were the prerogative of farmers and other heavy users and their market penetration was weak due in no small way to a very real distaste by the motoring public for smelly, noisy and rather poor performing vehicles. Certainly not the vehicle of choice for someone keen on driving or who spent a good deal of time behind the wheel .Being overtaken on the road by just about every other vehicle no matter how small was not exactly fun motoring! Nowadays with tremendous strides in technological innovation, a diesel engine can match the performance of many gas powered cars and are much quieter and more fuel efficient. They are considerably less noisy not attracting much attention from passers by and far less smoky than before two major environmental benefits.
Getting assailed by something akin to a mobile coal burning power station with a decibel reading not unlike a space shuttle at take off, was a very unpleasant experience for those unfortunate enough to have a diesel motor in their neighborhood .How things have changed in just a decade. It's actually quite a status symbol now to possess a Turbo Diesel and undoubtedly the success on the endurance race tracks of the world on both sides of the Atlantic of two famous marques battling it out, has further enhanced the attraction of the diesel.(5) Technical Differences
A gasoline engine fires up with a spark from a spark plug and diesel ignition is achieved by the compression of the fuel in the cylinder. Diesel is much less volatile than gasoline and does not ignite easily unlike its cousin. Diesel ignites under pressure and is injected direct into the cylinder head requiring a sturdier head and block than the gasoline power unit. This accounts for the greater weight of the former. The Diesel runs at a much lower engine speed contributing to its longer life.
(6) Resale Value
Since the diesel far outlives the petrol engine if properly looked after, it retains a higher resale value as it gets older due not only to its reliability but to the reduced incidence of engine repairs. A gas engine deteriorates over time and as it gets older the chances of major wear and tear increase and the necessity of expensive repairs becomes inevitable. In contrast a diesel continues to perform well as the mileage increases thus making a high mileage vehicle much more attractive to the buyer than its opposite gasoline cousin.
(7) Environment
With the onset of global warming now evident, diesel engines are becoming more acceptable to the motoring public and average car buyer because of their reduced emissions and ability to be readily converted to take several alternative fuels. Ethanol and even vegetable oil are used to fuel some diesels where this is available. This will probably increase the uptake of diesel engines over the next decade.
The fact that a diesel powered car can still be functioning well long after its petrol cousin has gone to the great garage in the sky is an attractive proposition to an eco aware driver. One could quite happily buy just two cars with diesel engines over a span of say 25 to 30 years that would reduce the never ending trail of scrapped petrol cars going to the crusher. Although metal recycling is very advanced today this eco driving principle has not yet become one of mass appeal, not least of all because cars have become status symbols, particularly amongst young drivers who wouldn't be seen dead in a ten year old car.
(8) Running Costs
With regular oil changes an absolute necessity in maintaining a high level of performance in the diesel engine and at more frequent intervals than a petrol engine in the past it could be argued that this is more trouble than it is worth. However this frequent oil changing has also changed dramatically with the march of technological innovation. Service cycles of 15 or even 20,000 miles now is not unusual with high performing synthetic oils so that the extra cost of the servicing has been leveled out when compared with the petrol engine.
The one key factor to be born in mind when contemplating a diesel powered car is that it will take about three years or so to recoup the cost of the higher priced diesel engine so the owner must be prepared to keep his machine for considerably longer than would be the case with a gasoline powered unit in order to show a profit.
