THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM

For those of you who are not aware E10 unleaded fuel is only one month away in the UK. Many garages already sell only E10 as a standard unleaded fuel.

As of the 1st of September E10 which has a higher content of Ethanol (10%) will be normal in standard 95 RON unleaded fuel. Super Unleaded which is what I use in my S Type will have E5 97 RON. For some older cars including our S Types some original rubber fuel lines and rubber gaskets in the fuel lines are not compatible with E10. The Ethanol content damages the older rubber turning it in to a soft porous mess allowing fuel to leak. Any product you buy now, if you are replacing fuel lines, is or should be E10 compatible but many of our older cars which might not have been restored could be running the original fuel hoses.
If this is the case then I suggest a couple of things.

!. Start using Super Unleaded E5 fuel. Slightly more expensive but better for your car.
2. Start to over haul your fuel system hoses just in case you cannot get hold of Super Unleaded fuel where you live. Mainly the ones in the boot from the tanks to the copper hose which are hidden behind the side panels in the boot and then the hose running from the fuel bowl to the carbs.
3, Again if your carbs have not been rebuilt over the last say five years look at a new rebuild kit with new rubber seals which will be E10 compatible. There are some New Old Stock kits still out there and these are not what you want to buy.

The hose you need to look out for is marked R9, an example of the pipe from a dealer - https://www.thehosemaster.co.uk/r9-unle ... fuel-hose/

I replaced all mine last year as they were already getting porous and had a smell of fuel in the boot.

One man's history in the USA with 10% ethanol fuel for circa 15+ years on five vintage British cars including an S Type: All fuel here in Oregon and previously California, is 10% ethanol unless specific high octane fuel is searched out and the price is 25% higher than standard pump grade. On my S Type I am still running the factory original plastic (?) hoses to and from the twin fuel pumps in the boot and from the glass filter bowl to the carb metal line. No sign of deterioration, seepage, or fuel odors. Car is run regularly year round but not for high mileages. Original carb diaphragms only changed last year as part of a comprehensive engine overhaul. Appeared to be working without leakage prior to that. They lasted 167,000 miles without issue. Running SU fuel pumps with diaphragms renewed about 8 years ago for age, no seepage or perforations noted at the time of renewal. Two Morris Minors and one Austin 1300 (America) are running standard SU pumps but rubber hoses to the carbs renewed 12 years ago due to age only, no leakage noted. So my advise, which will likely be vehemently refuted, is "don't panic" but be observant of your fuel system. The USA has been the guinea pig for this and it has not been as near as dire as some predict. Same thing happened with unleaded fuel introduced some 46 years ago here.

That's good to know John, I'll be using our 97/99 octaine fuel on my Jaguars anyway that has only a max of 5% ethanol as I find they go better on it. It's only 10 pence a litre more.