Can a diesel engine run on gasoline?

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SUMMARY

A diesel engine cannot run on gasoline due to fundamental differences in ignition methods and fuel characteristics. Gasoline requires a spark for ignition, while diesel relies on compression to ignite atomized fuel. Although there are anecdotal instances of diesel engines running on gasoline for short durations, such as a VW diesel running for about 15 minutes after being mistakenly filled with gasoline, this leads to significant mechanical issues and potential damage to the fuel system. The Cetane index for diesel and the Octane index for gasoline highlight their opposing properties, making them incompatible fuels for their respective engines.

PREREQUISITES
  • Understanding of diesel engine mechanics
  • Knowledge of fuel ignition processes
  • Familiarity with Cetane and Octane indices
  • Basic principles of internal combustion engines
NEXT STEPS
  • Research the differences between diesel and gasoline fuel properties
  • Learn about the implications of using incorrect fuel in diesel engines
  • Explore advancements in compression ignition technology for gasoline engines
  • Investigate the effects of fuel quality on engine performance and longevity
USEFUL FOR

Automotive engineers, mechanics, and anyone interested in internal combustion engine technology will benefit from this discussion, particularly those working with diesel engines and fuel systems.

jethead
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I haven't read or heard about anywhere, but is it possible to run a diesel engine on gasoline/petrol?
 
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No. Gasoline requires a spark to start the process, although a very hot spot in a cylinder can cause pre-ignition (but still requires the spark to get the ball rolling to create the hot spot).
 
Gasoline must be atomized by carburetor or fuel injector, then ignited with spark.
Diesel is atomized by high-pressure pump & injector, then ignited through compression.

Trying to run a diesel with gas: there may be some miracle by which it would work, but only for a very short time. You would probably have to take the engine pieces home in a bag, though. :-p
 
I read that in a diesel engine, ignition occurs when atomised diesel fuel is injected into the hot, highly compressed gas slightly before the piston has reached the top dead centre. So I was thinking that the same method of ignition could be used in a gasoline engine.
 
My aim is to use low octane fuel in high compression engine without pre-ignition.
 
Diesel and gasoline are two fuels that have completely different characteristics. A good diesel fuel will be easy to ignite and will have a short ignition delay period because you want the fuel to ignite almost instantaneously. A good gasoline will be defined by the opposite: the more compression the fuel can withstand before detonating, the better it is (hence, difficult to burn).

Diesel fuels are measured with the Cetane index and gasoline with the Octane index. If a fuel performs well on an index it usually performs badly on the other.
 
diesel car can run on gas...for a limited period..case in point.. my girl friend filled my VW diesel with gasoline..there was enough diesel in the fuel system to restart tha car after she finished filling the tank ..and modern electronics controlled the mixture enough to quench detonation...the perfromance was dramacticlly reduced ( she picked me up after the car was fueled) ...but when it was shut off..it would not restart as all the diesel fuel had been consumed..had to call tow truck and the VW dealer had t o drain the fuel tank...no engine damage was suffered..duration of time running on gas was about 15 minutes...10 miles
 
Well, there's no saying that gasoline won't ignite when injected at the correct timing.
 
There are plenty of mechanical issues (fuel pump and injector lubrication problems, for instance) to contend with as well as the uncontrolled burn you will end up with.
 
  • #10
Well, then I guess pre-cooling of intake air and fuel, and a good liquid cooling system will help in achieving the high compression ratio.
 
  • #11
RangerMike, your diesel ran because of the carbon build-up in the cylinders which was preheated by the diesel fuel operation before the gas got there. You will find out soon enough (unfortunately) the damage that "dry" gasoline does to a diesel injection system. :(

So, will a diesel engine run on gas? "Kinda" I guess is the best reply- without the fuel switch over, the simple answer is no. Although I must say there is experimentation going on to make a gas engine that will ignite by compression... there sweems to be problems with emissions at this point- NOx in particular.
 

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