Vaperlock- problem caused by fuel ( mostly petrol with a high % of ethanol ) and ( in my experience a mechanical fuel pump mounted on engine) , vaporizing and causing fuel starvation. The fuel pump will pump liquid, but fails with vapor.

In the early 80s I worked in Zimbabwe out in the back of beyond. Often getting to a job involved a 2hour drive in at least 40c ( possibly higher). At that time "petrol" was a mix of local produced ethanol and imported ,refined petrol. After a short time on site, the van refused to start. There was a decent spark, but no fuel into the Carb. We found a temporary cure was to pressurize the tank( fancy way of saying stick mouth round fuel filler and blow) and eventually the engine would get fuel and start. A more permanent method was to add some diesel to the tank when filling, thus increasing the boiling point and keeping liquid to the pump.

i don't know how many UK vehicles still use the old mechanical pump . But for those that still do , increased levels of E and higher temperatures might cause problems, and my cure on ye olde 80s style engines most possibly will  cause problems to CATS and sensors in the exhaust. The cure- I'd suspect some sort of hot weather pressurization system for petrol tanks. or some form of vapour detection in fuel pumps, leading to a tank pressurisation to get liquid fuel to the pump.

Food for thought?

The simpler cure than that used by most manufacturers was to have a fibre insulator block between two paper gaskets to prevent heat soak from the engine block.

Petrol is by far the more volatile component in the mixture, so increasing ethanol content will reduce evaporation.

In the UK the Ethanol is not above 10% so not rising & in some world regions it is 85% so not sure about the concerns in the OP.

Then with E5 in parts of the UK it is not even 5% ethanol. 

 

 

They've been selling E10 petrol for 10 years over here in Germany. And I've seen a few stations selling E85 (also available since around 2008 here) and never heard of any issues.

10 minutes ago, Phil-E said:

They've been selling E10 petrol for 10 years over here in Germany. And I've seen a few stations selling E85 (also available since around 2008 here) and never heard of any issues.

My previous 1.4TSI Octavia hated E10, within 10 miles of filling with E10 the wideband lambda sensor would throw a fault code but not go into limp mode. Every time I cleared the code and it would stay cleared until the next time I filled up with E10. Not my problem now as it went to the ex...

Quote

4116 - Oxygen (Lambda) Sensor B1 S1
          P2196 00 [237] - Signal too High (Rich)
          MIL ON - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 41020 km
                    Date: 2017.09.24
                    Time: 17:39:43

                    Engine speed: 3077.00 /min
                    Normed load value: 44.3 %
                    Vehicle speed: 135 km/h
                    Coolant temperature: 93 °C
                    Intake air temperature: 35 °C
                    Ambient air pressure: 990 mbar
                    Voltage terminal 30: 13.358 V
                    Unlearning counter according OBD: 40
                    Exh mss flw bef main cat conv bank 1 filtered: 142.7 kg/h
                    Exhaust gas temperature before catalytic converter: 692.83 °C
                    Oxy sensor 1 bank 1 char curve offset: -0.07004
                    Oxygen control: adaptation value at partial load: bank 1: 1.04538
                    Long-term fuel trim bank 1 at idle: -0.84 %
                    Short term adaptation of mixture formation bank 1: 3.1 %

 

5 hours ago, PetrolDave said:

My previous 1.4TSI Octavia hated E10, within 10 miles of filling with E10 the wideband lambda sensor would throw a fault code but not go into limp mode. Every time I cleared the code and it would stay cleared until the next time I filled up with E10. Not my problem now as it went to the ex...

 

 

I bought this car over 2 years ago and have used E10 for almost every fill up since then. Zero problems and runs as smooth as on E5 (have used it a couple of times).

 

Weird.