It could well be but I thought I'd try it for a prolonged period and see what results I came up with. All the rants people have on BabyBMW about V-Power and the like I thought it may be interesting to see what happened. All my diesels have been run on cheap supermarket tat with no problems whatsoever, well apart from catastrophic engine failure on my Mondeo ST Tdci but I'm sure that wasn't fuel related!tim wrote: Fri Mar 22, 2019 3:25 pmPossibly irrelevant comparison with the 140 but I did this with my 135 and it was cost effective to continue using Super. I'd forgotten how much cheaper petrol is than diesel so I'm quite happy putting SUL in my new one!McSwede wrote: Fri Mar 22, 2019 1:10 pm For curiosities sake I may run it for a month on std unleaded instead of SUL just to see if I can notice any difference and see what it does to my mpg and running costs.

It's great to be able to buy SUL at £1.20 and above compared to diesel and I still find it ridiculous that due to mileage claim back, the M140i is cheaper to run than my C220d AMG Line Premium Plus (sorry, long winded name make me chuckle).
The service interval is just bonkers to me though.