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51

Torque is the name of the game. High torque is needed to move heavy loads. If comparing a gasoline engine to a comparable diesel engine the diesel will always have higher torque. The higher torque comes from the need for a higher compressing ratio needed for compression ignition. To achieve the higher compression ratio a longer stroke is required. The longer ...


29

The main concern with using petrol in diesel systems is that diesel is used to lubricate the fuel pump, which petrol cannot perform adequately, which will shorten the useful life of the fuel system. I think it's fair to assume that in the 5-6 seconds the fuel bowser was able to deliver no more than 2 L of petrol. 2 L out of 60 L is around 3%. I wouldn't ...


23

A major, but often overlooked, reason for the dominance of gasoline engines in passenger vehicles is the need for diesel engines in heavy vehicles. A given quantity of crude oil, depending on its composition, will yield a given quantity of diesel, a given quantity of gasoline, a given quantity of candle wax, and specific given quantities of other petroleum ...


20

These are things I check before buying a car (in addition to Alex's advice): Make sure it has radiator fluid (at a proper level). If the radiator fluid is empty, it probably has a radiator leak, they probably have not been watching it, and the engine probably has heat damage. The thermometer won't work without radiator fluid so they won't see that the car ...


20

To OP’s main question: “Why do heavy vehicles almost always use diesel engines?” Answer: Cost and dependability. Diesel engines are significantly more expensive, but have lifetimes many times greater than gasoline engines. For a commercial vehicle that is on the road all day every day, it adds up to big savings because of the better fuel efficiency and less ...


17

It's a Diesel, which means that you usually have a high detergent oil in an engine that dumps combustion by-products like soot into the oil as part of its normal operation. Given the age of the vehicle I'm not surprised that the oil has noticeably darkened after 10 miles - one of the older Diesels I owned a while back did that during the time it took to run ...


17

You "can" use diesel in a gasoline engine. In the sense that it will run, but it will run poorly and smoke A LOT. But the problem with gasoline in a diesel engine is that diesel engines rely on diesel to lubricate various components (diesel is an oil). If you put petrol through these components, it washes away all the lubrication and will cause them to ...


16

Since the diesel has no physical throttle, power is controlled by limiting fuel. Air is always available so any unintended, un-metered fuel will cause the engine to increase rpm and power output. The most common sources are blowby oil and oil leaking from a worn turbocharger, these then pool in the intake manifold. This engine oil gets pulled into the engine ...


16

The main problems from misfueling a diesel car with petrol stem from the fact that (as Zaid points out) petrol doesn't provide the lubrication effect of diesel fuel and as a solvent it can actually inhibit the diesel that is there from providing lubrication and this can do nasty, nasty things to the fuel pump which can then have knock-on effects to other ...


15

I'm surprised this has not been mentioned. Have a compression test performed on the engine. This will expose many major engine problems like head gasket leaks, damaged valves/valve lands or rings. It is a simple, inexpensive test that can save you from some of the most expensive repairs a vehicle may need. I would consider a compression test absolutely ...


15

In Short its based on low burn rate of diesel plus the longer stroke of the diesel engine. First you must understand the difference between these engines, the diesel works on purely compression of fuel , heating and generating bang to produce power, the gasoline on the other hand is natively twitchy and needs a spark to explode and produce power on its own. ...


14

Most modern diesel engines (ie: engines after mid-80s) require some electricity to run because they are electronically controlled. This is due to computers controlling the fuel charge and monitoring of the engine itself. Without this, the diesel engine has no control. They also require electricity to power the primary fuel pump, to move the fuel from the ...


13

I have both a 2004 Bora TDI (Jetta Mk4 in the US) and a 2012 Mk6 TDI Golf. When either of these cars requires it's warm up system, it will automatically switch it on for the time it needs. This is signified by the glow plug light illumination on the dashboard: Once it's up to the temperature it requires, the light goes out and the car can be started. I ...


13

I would say there are two major reasons. First, the seals and o-rings used in diesel engines can't tolerate the chemical composition of gasoline. They are designed to tolerate the chemical composition of diesel only. Second, the kind of pressure needed to inject diesel can't be tolerated by gasoline. The Chevy Duramax diesel engine has 23,000 PSI in the ...


13

The recall is not to remove the cheating logic; it is to actually make the engines meet emissions requirements so they do not violate the law any more. From Autoblog's initial article on the scandal: Volkswagen intentionally installed software in nearly a half-million diesel vehicles that helped the cars evade substandard results on emissions tests, the ...


13

The only two stroke diesel i'm aware of is the Detroit diesel. The Detroit diesel does use forced induction but not in the way that you think. From your description it sounds like your describing a two stroke gasoline engine. The engine draws in air into the crank case. Then compresses it and shoots it into the combustion chamber. This setup works well ...


13

The common way that effective overspeed protection is provided on diesels in the oil and gas industry is way more simple than using electronics to effect a shut down. The only effective and reliable method of shutting down an overspeed diesel is to block intake air. A simple valve is installed on the intake air passage which closes when air flow through the ...


12

As already stated, the ignition source between gasoline/gas engines and diesel engines are different and this is the primary reason for the difference in sound. I will try to explain those differences so you you'll understand why the sound is there with one, rather than the other. NOTE 1: There is a diatribe here, but bear with me as I attempt to answer the ...


12

Two types of sounds There are two sound types that emerge from a diesel engine. Combustion Noise Mechanical Noise Combustion noise is created by the compression ignition process which compresses the air fuel mixture of the gas which creates higher temperatures upon increased compression until combustion occurs. Mechanical noise is created primarily by ...


11

Given two engines of similar weight, both operated at their respective optimum efficiency (i.e. maximum mechanical work done per unit of chemical enthalpy in the burnt fuel), you will end up with similar fuel consumption for either engine type. But a Diesel engine will generally offer slightly more power out of this, by giving more torque; that's how it's ...


11

They aren't better for the environment But efficiency is often confused with emissions. The average person would think that because diesel engines are more efficient and burn less fuel, they must be less harmful to the environment. I think few can be more authoritative than the folks at Bosch on why diesel engines are so prevalent (emphasis my own)¹: No ...


11

Glow plug is merely an aid for starting the engine. There are many designs still produced today without any glow plugs (eg military diesels run without any electricity), and even many modern diesel engine can be started if glow plugs fail (unless onboard computer prevents that). Diesel's auto-ignition comes from heat generated by adiabatic compression of ...


11

This will not be a problem - in fact, some of the older truckers used to add 2% of petrol to the diesel to help in winter conditions to help reduce waxing of the diesel fuel.


10

Despite any opinions of safety it seems that gas tanks are manufactured to not accept more than 95% of their total volume because of regulations. Here is a quote from the US Department of Transportation Federal Motor Carry Safety Administration Regulation 393.67 Subpart E. (12) Overfill restriction. A liquid fuel tank manufactured on or after January 1, ...


10

It sounds like you already know why a gasoline engine keeps the fuel/air ratio as close to the stoichiometric ratio as possible, but just for the sake of information for anyone else: The stoichiometric fuel/air ratio is the amount of oxygen required to burn all of the gasoline completely. A "lean" burn leaves some oxygen leftover and a "rich" burn means the ...


10

tl dr: By adding a throttle plate, it creates the vacuum needed to draw in gasses from an EGR valve. Since diesel engines are designed to run lean, they don't need throttle plates to run. They utilize the amount of diesel fuel needed to keep the engine running and to provide the work needed to do the job required of them. One of the inherent issues with ...


10

The most likely cause is that the cable that runs down to the starter motor has been rubbing against the body or the engine and has worn through the insulation.


9

You can see the ill-effects of misfueling in this episode by Fifth Gear. They put petrol (gasoline) in a diesel car and vice versa. A summary of the differences between the two fuels: Diesel does not burn as easily as petrol. It relies on auto-ignition under compression rather than spark-ignition to combust. Diesel has a higher AFR value than petrol. ...


9

You can run gasoline in a diesel motor, but it causes problems. As mentioned elsewhere, when you compress the fuel/air mixture enough, it gets really hot then ignites. With diesel, this is ok, because the fuel burns (relatively) slowly, so it doesn't need to be timed very well. Gasoline, on the other hand, burns really fast. If you consistently ignite the ...


9

The engine operates on high compression to ignite the fuel at very low RPMs which gives it it's distinctive sound. The lower RPM makes the ignition of each cylinder easier to hear and the compression ignition system gives it it's rattle like sound. This is as opposed to gasoline engines that operate by a spark/compression ignition system. The key to ...


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