E10 fuel in K series Elises

[hotpurple]

Thanks Timbo, I’m actually a chartered mechanical engineer, so I understand  the problem and that Lotus just haven’t tested it (and probably never will). My real question was just has anyone successfully used higher ethanol content fuel and not seen any problems as a result. As you say, the issues are likely to be corrosion of the fuel lines and hardening of the seals and rubber hoses, leading to a potential fuel leak. 
The Land Rover Freelander is supposed to be ok, so that would indicate that the engine itself and any Rover bits (fuel rail, injectors etc) are ok. It’s just any of the Lotus specific bits that are the issue, e.g. tanks, fuel lines, pumps etc. Are they the same between the Toyota and Rover powered cars?

[timbo]

Standard tanks are steel, so the point about long-term storage of E10 applies re. moisture. However, normal best practice will mitigate against this, eg. reducing the volume of fuel to a minimum, regular running of the engine, etc. 

There is a specific E10-compatible standard for fuel lines, which is R9. This is readily available should any replacement be necessary.

For further reading on hoses there is a very comprehensive article here:

http://www.volksbolts.com/faq/fuelhose.htm

[hotpurple]

Thanks Timbo, there’s some interesting information in there. From what I’m reading on that site, all fuel injector hose should be R9 already, or have I misread that?

[timbo]

SAE J30 specifies that R6 fuel hose is rated at 50psi (for ID up to 3/8") and R9 is rated to 100psi (up to 1/2" ID).

As I understand, the K-series injection runs with a 45psi regulator, so R6 spec hose would be marginal.

[GaryEliseS1]

Hello,

interesting that Esso say there pumps are labelled E5 but this is apparently  0% ethanol and it is just labelling issue. The lotus website says E5 is ok as it is lower that 10%  Have a look for yourself, but it seems Esso unleaded would be ok.  https://www.esso.co.uk/en-gb/fuels/petrol I

ESSO: Although our pumps have E5 labels on them, our Synergy Supreme⁺ 99 is actually ethanol free (except, due to technical supply reasons, in Devon, Cornwall, North Wales, North England and Scotland). Legislation requires us to place these E5 labels on pumps that dispense unleaded petrol with ‘up to 5% ethanol’, including those that contain no ethanol, which is why we display them on our Synergy Supreme⁺ 99 pumps.

Lotus: Ethanol E5 & E10 Do not use Ethanol blends with a higher concentration than 10%. 
https://www.lotuscars.com/en-GB/fuel-compatibility