56
votes
Accepted
Why do heavy vehicles almost always use diesel engines?
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 ...
- 16k
29
votes
Small amount of wrong fuel type put in the tank
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.
...
- 39.1k
28
votes
Why do heavy vehicles almost always use diesel engines?
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 ...
- 1,723
22
votes
Why do heavy vehicles almost always use diesel engines?
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 ...
- 221
17
votes
Why not use gasoline on diesel engines or vice versa?
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 ...
- 8,838
16
votes
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Diesel Engine Runaway - What is it?
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 ...
- 11.6k
16
votes
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Small amount of wrong fuel type put in the tank
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 ...
- 9,980
13
votes
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Modern cars and diesel warm-up time
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 ...
- 23.4k
13
votes
Why not use gasoline on diesel engines or vice versa?
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 ...
- 16k
13
votes
Accepted
Why are VW recalling their cars to remove a defeat device?
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:
...
- 39.1k
13
votes
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Two-Stroke Diesel Engine - Do they use forced induction on them?
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 ...
- 16k
13
votes
Accepted
Is it possible for a diesel engine computer to detect (and prevent) a runaway condition?
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 ...
- 605
12
votes
What's the cause of Diesels' typical clatter noise?
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 ...
- 32.9k
12
votes
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How did they start diesel engines before the glow plug was invented?
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 ...
- 805
12
votes
ATF in engine oops
I would run the engine again for a few minutes and then drain that engine oil as it will have any ATF that was still in the galleries.
Then fit a new filter and refill with fresh oil.
After that you ...
- 34.6k
11
votes
Why do heavy vehicles almost always use diesel engines?
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 ...
- 111
11
votes
Accepted
How are diesel engines better for the environment than gasoline?
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 ...
- 39.1k
11
votes
Small amount of wrong fuel type put in the tank
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.
- 34.6k
11
votes
VW Polo Engine Oil Light Blinking on hill
I have a VW TDI diesel, but an earlier model.
Your oil light comes on when there is a gradient but not because of a gradient. A mechanic who blames the tilt of the ground for the light on the dash ...
- 5,078
10
votes
Why does a petrol engine need to maintain an air-fuel ratio, while a diesel engine doesn't?
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 ...
- 2,055
10
votes
Accepted
Why don't all diesel engines have throttle plates?
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 ...
- 152k
10
votes
Accepted
What would cause a short to ground while driving - how to locate the problem?
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.
- 23.9k
9
votes
Why not use gasoline on diesel engines or vice versa?
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 ...
- 39.1k
9
votes
Accepted
Why not use gasoline on diesel engines or vice versa?
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 ...
- 617
9
votes
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What's the cause of Diesels' typical clatter noise?
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 ...
- 256
9
votes
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Diesel engine timing?
Diesel engine timing is accomplished through the fuel injectors (they inject fuel at the proper times). Proper timing prevents pre-ignition because there's no fuel in the cylinder yet to ignite. Glow ...
- 4,900
9
votes
9
votes
Accepted
Why does "i" stand for petrol?
The i is a leftover from the 1970s, when a few companies (BMW and Mercedes, notably) started replacing the carburetor on their petrol engines with fuel injection. The marketing department saw an ...
- 4,422
8
votes
Accepted
Would a non-turbo diesel perform better in high altitudes than a comparable gasoline engine?
Non-turbo diesels lose less power in the Rockies
At least according to the SAE J1349 standard.
(Calculations shown below).
Assumptions
Dry air pressure in the Rockies = 90 kPa ( at 3000 ft)
...
- 39.1k
8
votes
Accepted
Can diesel engine be harmed as easily as gasoline engine by over-revving?
The rev limit of a petrol (gasoline) engine is generally set to protect the internals of the engine. Less sporty engines are designed to a cost and their components may not have the strength or ...
- 1,688
Only top scored, non community-wiki answers of a minimum length are eligible