I can only go off experience.
I worked for 5 years up until recently driving power boats. We used to have to refill them every day, sometimes twice. Up to 1300litres of petrol a day.
When we moved marina to one that only had diesel we had to buy petrol from Tesco. We used 25l tubs to carry fuel.
We would then use siphon tubes to get the fuel into the boats.
I've never seen any contamination in the bottom of the tubs in the whole time.
The only time I've ever had problems was when we bought some bladder tanks for the small boats.
http://www.orca.eu/uk/forces.php?id_page=57
The increased ethanol in petrol nowadays stripped the lining of the tank which is put there for manufacturing. It created a snot like substance. This quickly blocked both the tank filter and the inline outboard motor filter.
One boat needed new fuel lines.
I notice the manufacturer Of those tanks list them as diesel only now.
So yes, there is a risk, as those people filling with Tesco and morrisons petrol unfortunately found out. If you don't remember here's a link.
http://www.autocar.co.uk/car-news/motoring/dirty-fuel-blights-thousands
I've always been a bit of a risk taker, I run my electric car to nigh on empty all the time. And I fill my fiat up as little as possible, as I find it a chore.
Yesterday I used the fiat for work. When I started in the morning, the warning of low fuel sounded, the gauge showed 1/4.
10 miles later it showed 1/8, and the petrol light came on. Can't remember exactly when it dropped to the last 1/16 , maybe 10 miles after that?
I've done nearly another 30 miles since.
So total of 60 miles since the sound happened and the dash said "low fuel"
That last 1/16 is still lit.
As I've said earlier, I have driven 18 miles on zero till I ran out.
So potentially 80 miles range after the 1st warning?
Btw, the range showed 30 miles when I started yesterday. My wife had used the car the day before in city rush hour.
I don't intend on running out again, I would limit my zero fuel range to 14 miles, but as Tesco have dropped the price for the weekend to less than £1 I'll fill to the brim at some point over the next 2 days.
