Hi, I just introduced myself and have a very basic question, just to be safe:

Should I use Euro 98 fuel (E5) for a XK150 (1958), straight from the pump, or add additives?

I remember my father telling me to use plain Euro 98, but this memory hasn’t been the most important one of him for a while now, so I am hoping someone can reassure me....

Thanks!
Willem

 

Welcome to the forum Willem,

I've moved your question from X150 forum to XK120 / XK140 / XK150 forum.

The confusing naming of Jaguars. The X150 forum is for the XK/XKR which was produced 2006-2014. You will see from my signature picture that it is very different from your XK150 of 1958.

Your car was originally designed to run on 95 or 98 octane leaded fuel. This has become increasingly difficult to find in Europe and most owners have had their vehicles modified to use unleaded. Members here with the same model will know the details of this.

Graham

 

My XK150 runs fine on Unleaded or Super Unleaded (for example BP Ultimate Unleaded).

 

I would put 98 octane in, and also it might be prudent to add some Castrol Valvemaster. This is because hardened valve seats started to be installed by Jaguar when the US started taking the lead out of their petrol. This was in the 60s and your car may not have these hardened seats.

https://www.ebay.co.uk/p/Castrol-Val...iABEgLFXfD_BwE

However, I don't think Castrol now make it, but it is still produced: -

https://classicvalvemaster.co.uk/

According to their website, it is the same stuff, and made by the same manufacturer.

I always put it in my MG Midget tank when I fill up. The Midget will run OK on 95 octane but I have recently started to use the 98 octane and it seems to run better. My mileage is so low that the extra cost is trivial.

 

i always use LL100 aviation fuel it has no alcohol and is 100 octane leaded gasoline you can buy it at most small airports but you must tell them it is for an airplane you fly off site. they cant sell if you say its for road use