NOT a good idea running on petrol!. (strictly emergency only..(WITH some oil added)).
Petrol is more 'explosive'...And the popping sound is pre-ignition, Or 'pinking' as was known in the old days of low grade fuel.
Hi octane fuel has 'Bang restraint' if you like.
Low octane does not, So detonates too soon in the compression cycle..Often igniting before the spark plug fires it off when the engine is hot in petrol engines with a compression ratio of 7 to 1 or so upwards.
To run it in a modern high compression car ( 9 or 10 or so..) the ignition would have to be retarded.. .( ..Like the ..driver! ).
SO....juss' imagine....You shove petrol in yer' Mulitfuel with a compression ratio of..OVER 22 to one!!!..Well, think about it Fuel density compensater or no!
By the time the fuel density compensater has compensated 'enough'..the engine has the pulling power of....."Rice pudd"!.
Diesel has a cetane rating.
Petrol = 'Bang'....................brief short power in the stroke. (Shock heat stress).
Diesel = 'Slow burn'...........power over all the stroke. Smooth long and reasonably cushioned.
Those running with ATF added NOTICE the improved cushioning and smoothness together with more power.
In other words... Ya' get's MORE bang for your buck, (As I do with),
CLEAN contam, (Wrong fuel put in nicely by folk's in their cars), Plus With Filtered waste ATF and hydraulic oil, And Waste (CLEAN) Cable oil.
All that, AND more Miles to the gallon.
I hope that helps.
OH!, And Waste engine oil?...Na'hh, Never.