The new E10 fuel

[JimMann]

Brian, as given elsewhere on the Forum, the government compatibility table information is compiled from information presented to the government from the car manufacturers and is related directly to the point of the vehicle's engine's ability to accept burning E10 fuel. The compatibility issue of the materials within a car's fuel system is not addressed.
For Jaguars, the engines from MY 1992 are okay with E10 fuel, but the materials of the fuel system in cars from 1992 onwards could have been changed / repaired / upgraded many times and may not be original specification, so no manufacturer is going to give carte blanche to those parts.
Also, bear in mind that E5 fuel has been in use in the UK for many years, simply doubling the percentage of the Ethanol content does not make it more aggressive towards the fuel system materials, E10 simply provides more of it.
Jim

[b.l.hayward]

Jim, what I have been lacking in connection with ethanol in fuel is some form of qualified, as opposed to anecdotal, references. In other words, what has happened as opposed to what could happen. I have to confess that I have only read items that have just 'come across the desk' ie picked up because they were relevant rather than searched for by me. The risk with this is that you probably don't get sufficient information to inform your thinking and actions, and I accepted the conventional wisdom the ethanol was 'bad' for older cars (ref the RAC position). I probably stopped looking before I should have.

So, several hours and a couple of days later I have come across this item which, at least for me, has changed my perception:

https://www.hagerty.co.uk/articles/main ... assic-car/

Not only that but I have belatedly (!) checked my Jaguar Handbook (1985 V12 XJS HE) and it says:

"Ethanol:
Fuels containing up to 10% Ethanol may be used. Ensure the fuel has octane ratings no lower than those recommended for unleaded fuel. Most drivers will not notice any operating difference with fuel containing ethanol."
(I imagine that this was specifically included because of the US export market and the fuel available there. It does also mention that ethanol can damage paint.)

So I conclude that Jaguar would not have included the use of Ethanol in their warranty if it was likely to cause them major engine warranty claim issues. You would also expect that if they felt that petrol supply pipes would rapidly degrade they would have said something about this.

My current conclusions - E5/E10 should not damage any engine or fuel-related components in my V12 but could finish-off old flexible petrol pipes earlier than otherwise might be the case, and there are mitigating actions that can be taken for storage of fuel in the tank over winter.

Tranquillity has returned (at least as far as it can with 1985 V12).
Brian

[BigCatXJS]

Good discussion - thank you.

I have always run my V12 on premium fuel (mostly Shell V-Power that is E5 rated). Now I run all my cars on premium. I do less than 9k miles year across 3 cars, so fuel tends to hang around in the tanks - especially over winter. Interesting that some Mercedes cars up until 2006 are not approved to run on E10.