A few years ago, maybe 15 or 20, I read somewhere that it was actually considered prudent for petrol cars to have a couple of litres of diesel run through them annually.

Not sure if anyone here remembers anything like that?

I guess it goes in the same box as the annual change of the MAF Sensor, CrankSensor disconnect Oil Change and other such bollox ............ but, is there some crumb of truth in it somewhere along the line??

I 'think' the idea was some kind of upper cylinder lubrication ......... ??

Pete

 

heard of diesel owners putting petrol in when its freezing in winter

 

maybe ok for 15-20 year old cars without the technology of today!

 

Up to 30% petrol in diesel acts as a winter anti wax big time, not so sure about diesel in petrol now days. It probably acted as an upper cylinder / valve lube years ago.

 

my dads a diesel engineer, bn working with engines for 55 yrs never heard of it being good for a petrol car to put diesel in tank, it has a much higher flash point etc etc than petrol, I would add this one to your bollocks pile
He did say though as long as it was only a couple of litres of diesel the car would run but wouldnt like it too much and you would be way down in power.

Graeme

 

I did nearly fill mine with it first time I took the car out ! stopped at the pumps, saw two green and one black pump, remembered I needed to put super unleaded in, checked it was the middle ( green ) pump, and still managed to pick up the wrong one - was just about to put the nozzle in when I noticed....

Please feel free to call me a muppet

 

Maybe in about 5000 posts' time.

 

I'm pretty sure diesel would cause severe detonation, and your cocklink would light up like a Christmas tree

 

Bloody Hell, never thought of that!!

Would I need to wear some 'DickCans' on my head too??!!

Also, I would need some spotty, hippy geek next to me with a Laptop - doing a Rolling Re-Map??

Pete

 

It does, but it will cause the fuel to burn far hotter and will f*ck your engine. You can use a 20% mix if youre trying to get an old diesel through its emmissions test though, but do it on an empty tank and fill up afterwards.


Simon

 

Wouldn't it actually increase the RON rating? Like putting anything else non-flammable (or less flammable in the case of diesel) water, octane booster etc?

 

Not sure if its measured the same way, but if it is what would the RON rating of standard diesel be?


Sorry if its a silly question

 

Not it wouldnt add to the knock resistance; if it were that easy we'd all be adding 20% H2o to our fuel tanks.....

 

Well, I didn't mean it quite that way - not to imply you could get better performance as such, just less knock. And you wouldn't put water in the tank though spraying a fine mist in with fuel air mix works apparently

 

I understood you perfectly well.

 

I used to run my nissan sunny off petrol diesel mixes...syphoned out the tanks of all the numpties who put the wrong fuel in their car. (free fuel )

anything more than approx 33% diesel in the mix and the thing would be a bit of a pig to start on a cold day and stalled easily when cold. But when it was warm was fine.

Just the trail of smoke everytime you gunned it was pretty bad, very handy at getting people up your **** to back off though - also helped stop the foglamp fanatics from dazzling me in the mirrors too And high-mid/revs+light throttle caused mild pinking (until I disconnected the vacuum advance on the dizzy ).

It ran with 9:1 compression and was tuned with timing set at 3 degrees BTDC as stock for 90Ron fuel - which would explain why it wasn't fussy about running on crap fuel

 

anyone?

 

It cant be measured; resistance to knocking is measured using a special single cylinder spark ignition engine and you cant light diesel with a spark... Consider also that youre suggesting attempting to measure resistance to the very action necessary for a diesel engine to function.....

Simon

 

http://www.straightdope.com/mailbag/mdieselvsgas.html

lol

I don't think I'll be trying it

 

IIRC, diesel is measured in cetane and not Octane

 

Man thats the craziest thing i heard in ages, i just wouldnt want to try that at all.

 

Many years ago was given aviation gas instead of petrol. It was dark and we were in a hurry (waiting for the Russiansto invade Western Europe)put it in a 4.2 litre straight six Jaguar equipped recce vehicle by mistake. Went like **** for a while. Best exercise I ever did!!!!