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Automotive Can a diesel engine run on gasoline?

  1. Jul 27, 2012 #1
    I haven't read or heard about anywhere, but is it possible to run a diesel engine on gasoline/petrol?
  2. jcsd
  3. Jul 27, 2012 #2
    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).
  4. Jul 27, 2012 #3
    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. :tongue:
  5. Jul 27, 2012 #4
    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.
  6. Jul 27, 2012 #5
    My aim is to use low octane fuel in high compression engine without pre-ignition.
  7. Jul 27, 2012 #6

    jack action

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    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.
  8. Jul 28, 2012 #7

    Ranger Mike

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    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
  9. Jul 28, 2012 #8
    Well, there's no saying that gasoline won't ignite when injected at the correct timing.
  10. Jul 28, 2012 #9


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    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.
  11. Jul 28, 2012 #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.
  12. Jul 28, 2012 #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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