Reply To: Fears for owners of older cars as government consults on new less polluting fuel

[Eddie]

In high enough concentrations bio-ethanol can corrode rubber (seals, pipes, etc). There are alternative materials that can withstand the damage but they haven’t been mandated fitments, only some manufacturers have used them anyway as globally bio-ethanol now has a bigger market.

There’s more in this article https://www.rac.co.uk/drive/advice/emissions/what-is-e10-fuel-and-how-could-it-affect-you/