Hello everyone
I wonder if I could ask for some advice please as I am getting conflicting suggestions. I am the proud owner of a 1960 MK9 which has the 3.8 XK engine. My question is whether I should be using fuel additives in the UK and which fuel grade is the better option to use?
From the advice I have been given so far it seems Ethanol content in UK fuel is 10% and has the potential to aggressively attack the aging system, also unleaded has the potential to damage values
Therefore I would welcome advice please from other more experience classic car owners on what they do in terms of fuel additives which would be enormously helpful
Many thanks in adavnce

 

I had a 1959 3.8 Mk ix, in the states, years ago. Loved that car. Anyway, you need to really do some research on this. Removing lead from gasoline finally elevated American IQs enough to realize they were being ripped off by fuel companies. There are a couple of issues: octane, of course, and the alleged destruction of vale seats in IRON head cars. Aluminum head cars may (and probably are) immune. Also... most mechanics state-side have begun questioning the need for any sort of seat "upgrade" even to iron-head engines (not coincidentally, most US cars from the recent past). Dig into it all before possibly wasting time and money chasing an illusion. IMHO

 

Howdy Graham. Sounds like you're new to the hobby. I wont speak to additives in the performance sense, but if your car sits for any length of time (a month plus), I would consider something like Sea Foam as a fuel stabilizer.
I've let old junkers sit for years with this in the tank. Just add a fresh battery, prime the carb, and fires right up AND runs fine on the old gas.
Don't know if you have Sea Foam in UK-land but no doubt there's a similar product available. Marvel Mystery Oil could have similar effect.
I'm no expert on this matter, just many years experience.
Probably already multiple threads a mile long on this, and this may even turn into one -
You could always do a thread search for more fun to be had!

 

Many thanks both for your insights - I tried searching the threads however nothing was returned that was relevant - I will keep trying different search strings!
I am on the journey of discovery on this topic and fully intend to research fully in order to understand various options

Thanks for taking the time to share your thoughts

Graham

 

You bet! Oh, just had a thought. There are entire channels on youtube devoted to trying different products against each other.
I know I've seen one on fuel additives but can't remember the title or channel.

 

I think the basic question is: does one need to replace the "missing" lead with another additive for the health of the engine? Unless we're talking about a very high compression engine, I believe the correct answer is "no". But I'm not an expert. After years of American (iron-head) engines running on unleaded from what I've read the predicted engine Armageddon has not happen. Also, be wary, a lot of vids showing you how to "save your engine" are usually sponsored. Maybe one of the best places to looks would be Hot Rod forums?

 

Have a look at this thread. Lead fuel additive - Technical - Antique Automobile Club of America - Discussion Forums (aaca.org)

AND

Lead additive necessary ? - Club Cobra

 

Many thanks Scrannel for your comments - from all the research I am undertaking I am rapidly coming to the conclusion that to replace the lead content to protect the valve seats is not really a concern at all particularly as I only do limited miles in the MK9
My primary concern is whether the ethanol in UK fuels damages the fuels system weak points such as rubber pipes etc. looking into the additives there seem to be very mixed views on their success however I have found that ESSO synergy supreme+ 99 and 97 contain almost zero ethanol therefore is the best option I can see, providing of course I can find an ESSO filling station when I need to refuel!

 

Great ride -- have fun with her!

 

I love her!! named her Ruby

 

My s-type (2008) is red and have been thinking of a number plate: RBY TUES.

 

You could add Castrol Valvemaster to your fuel on fill-up like I used to do when I had my MG Midget.

https://www.classicoils.co.uk/additives

I used to buy mine on mail order, a few bottles at a time. You don't have to add much so a canister lasts quite a time. I assume your Mark 9 won't be a daily driver. In theory, t he XK engine valve seats were upgraded when lead-free petrol started to be used. Later versions deal with the ethanol issue, but you can buy E5 petrol, as Tesco sell it at my local store, so it is quite common.

 

I’ve not had valve recession issues and I’ve been I to classics for almost thirty years. I ran an additive 25 years ago, but it got hard to source so I quit and never looked back.

I run Stabil 360 in all my carb stuff. Old cars, small power, year round. Never an issue. Saw others have problems with ethanol. It’s also a fuel system cleaner. Amsoil sells one I’d like to try.

 

One issue addressed above is the impact of ethanol on older flexible fuel system components; this can (and will) degrade fuel hoses, diaphragms, etc. that are not made of modern, ethanol resistant materials...