Petrol in Diesel worse than Diesel in Petrol?

ballooba

The Indo quotes the AA as saying that putting petrol in a diesel vehicle by accident is more detrimental than putting diesel in a petrol vehicle. Surely it's the other way round, or else why have the wider gauge on the diesel pump?

Indo wrote:

This is because petrol in diesel cars acts as a solvent and can reduce lubrication and cause damage to the fuel pump. In extreme cases, it can result in bills of up to €2,000 and sometimes the engine has to be replaced.

The problem is less serious when diesel is pumped into a petrol engine. If less than five litres is used, the rest of the tank should be filled with petrol and the car will run as usual.

http://www.independent.ie/national-news/drivers-face-huge-bills-after-using-wrong-fuel-3312455.html

Dartz

Depends on the amount of petrol and ratio. Just enough cleans the ****e out of it.


But diesel in a petrol will only need to be flushed out with fresh fuel. Petrol in a Diesel could damage the whole fuel system.

deandean

Some petrol engines especially older simpler ones will run sort-of okay on diesel provided they have been started on petrol. There will 'knock' a lot though. Not recommended obviously. I am speaking from first-hand experience here of course . No subsequent problems.

Gotham

Watch this:

http://www.youtube.com/watch?v=b5xhPAundL4

Answer, both survive, but one can fail NCT afterwards.

babi-hrse

petrol in a diesel is less damaging than diesel in a petrol... petrol will burn hotter and most likely will result in retarded ignition. either way its not gonna be any help to the car. but no serious damage. but will lead to burn indents on the pistion heads.
diesel engines are far more robust they have to deal with alot more internal pressure than a petrol engine does. a diesel engine is like a nuclear sub that can hit 600m while a petrol engine is like the ww2 subs that will groan and pop at 400m
diesel in a petrol will likely shake the car badly and break your valves, head gasket. probably will result in oil leaks in all directions of the engine.
i know someone who put diesel in a piaggio moped and upon coppin it he tilted the bike over in the garage fourcourt over the drains and poured the fuel down it to the shock of the staff. refilled it with petrol and said it ran really rough for 20 minutes.

Indricotherium

Does petrol float on diesel?

Matt Simis

babi-hrse wrote: »

petrol in a diesel is less damaging than diesel in a petrol... petrol will burn hotter and most likely will result in retarded ignition. either way its not gonna be any help to the car. but no serious damage. but will lead to burn indents on the pistion heads.
diesel engines are far more robust they have to deal with alot more internal pressure than a petrol engine does. a diesel engine is like a nuclear sub that can hit 600m while a petrol engine is like the ww2 subs that will groan and pop at 400m
diesel in a petrol will likely shake the car badly and break your valves, head gasket. probably will result in oil leaks in all directions of the engine.
i know someone who put diesel in a piaggio moped and upon coppin it he tilted the bike over in the garage fourcourt over the drains and poured the fuel down it to the shock of the staff. refilled it with petrol and said it ran really rough for 20 minutes.

Hmm, don't think any of that is correct and Ive help multiple people who did both. In every case the Diesels were f)cked, injectors, pump etc ruined.

The petrol cars with diesel in them just needed draining and fresh fuel. Diesel just acts like low Octane petrol while petrol isn't compression ignitable and more importantly acts like no lubrication at all.


The fact a modern diesel is like a "nuclear sub" is exactly why they are so fragile. Its in no way a benefit at all.

GavMan

Explained roughly to me once as follows:

The detergents in petrol effective strip out the lubricants of a diesel engine and thus damage it to the extent of seizing.

Diesel, A lubricant itself, wont harm a petrol engine as much, but it will run very rough. If you lashed 20 litres into you empty tank, you should prob get it drained. If you but 1 or 2 into your empty tank and put 50 litres of petrol in on top, it should be okay, again a little rough but okay.

Best not to mix them up at all to be fair though.

Chimaera

Diesel engine fuel systems rely on the lubricating effect of the fuel for lubrication. Sufficient dilution with petrol removes this lubricity and will damage the fuel system, particularly on modern common rail systems which operate at very high pressure and with very tight tolerances on the components.

Petrol and diesel are soluble in each other.

A few litres of one into a full tank of the other you can probably get away with. More than that, don't even think about starting a diesel if you've put petrol in there. Call the AA and have them drain the tank. If you've tried starting the engine you'll now need to strip down the entire fuel system and clean/inspect it as it'll have pulled the petrol up into the moving parts of the fuel system.

Dingle_berry

Wasn't/isn't there a trick with older petrol cars that fail the NCT due to emissions where you add a little diesel for the re test and it reduces the emissions enough to pass?

Matt Simis

Reducing octane and making a car run worse (increases knocking / detonation etc) doesnt sound like something that improves emissions..

Maybe you are thinking of the old "add a bit of petrol" to clean out old diesel engines thing? Heard about it used on much older (20years+) or marine engines. But as above, pretty disastrous on new diesels.

Slevster

Am currently running the car with some petrol in the tank. Stupidly put some into the tank by mistake. Topped up with diesel. Continued the journey.(8l in 60l tank) When I stopped the car, it wont restart. Just kept turning. So left it to cool, and it started once cooled.
Have been topping it up since. (rang a break down guy, who advised)
Googled the life out of over the week end. Found a lot of conflicting info. But did find some good info (from a chap who drains tanks for a living in uk) He maintains (for my type of pd engine ) that no real harm will be done. Modern engine will simply not work if the system detects issues with the fuel sytem/injectors. If it runs, it may not be pleasant sounding, but as long as the mixture isn't too high, well then it should be fine. Biggest risk is to seals, and connection pipes.
However, next nct emissions would be interesting.
(plan is to dilute again by refilling once more when its down to 3/4 full, then run tank till empty and fill tank again, hopefully with only diesel this time. )

dgt

Matt Simis wrote: »

Hmm, don't think any of that is correct and Ive help multiple people who did both. In every case the Diesels were f)cked, injectors, pump etc ruined.

The petrol cars with diesel in them just needed draining and fresh fuel. Diesel just acts like low Octane petrol while petrol isn't compression ignitable and more importantly acts like no lubrication at all.


The fact a modern diesel is like a "nuclear sub" is exactly why they are so fragile. Its in no way a benefit at all.

This would be my main concern, no lubricating properties on lots of mechanical components is only going to end in disaster