Here in the UK we have Sulphur free and lead free petrol (gas). It's called unleaded and it's octane rating is 95 (it's the cheapest fuel). We also have 98 octane fuel called Super Unleaded which has additives to clean injectors and look after the catalytic converter.

Do you have the same in the 'States and does the argument as to which to use in your Jaguars arise!

 

We have something they call Super in the US and the specific octane rating varies a bit by geography. The ranges in the US are usually 87 (Regular) to 93 or 95 (Super)

The octane rating systems for the US (AKI) are a bit different than Europe (RON) so the numbers themselves aren't directly comparable.

Octane rating - Wikipedia, the free encyclopedia

 

[QUOTE=jimforrest (uk);1168985]Here in the UK we have Sulphur free and lead free petrol (gas). It's called unleaded and it's octane rating is 95 (it's the cheapest fuel). We also have 98 octane fuel called Super Unleaded which has additives to clean injectors and look after the catalytic converter.

Do you have the same in the 'States and does the argument as to which to use in your Jaguars arise!

Australia: Our 'leaded super' was phased out 20 years or so ago. Our 95 is called Premium and usually about 8 cents a litre more than the unleaded 'standard' 90/92 octane. 98 is also available but after trying it for a few tanks saw no benefit,so run with the 95 recommended by Jaguar.

We have never had fuel here that contained the nasties that led to the demise of the nicasil engines.

$1.25ish for 90 and $1.32ish for the premium depending on area.

 

87 regular 10% ethonal, 89 non ethonal, 93 premium 10% ethonal in Hawaii.

I run the 89 pure gas non ethonal in my Jag.

 

As others have said, the octane rating systems in North America and Europe, actually the rest of the world, are different.

In general, 95 octane in Europe is the same as 91 here.

Your 98 is the same as our 93 or 94.

Jaguar is very clear and consistent in it's advice to use 95 RON. The engines achieve full rated performance with this grade of fuel. Anything higher is a waste of money.

The concept of using fuel with less than a 95 RON rating usually starts a fight, so I'll leave that one alone.

The idea that 'super' gas consistently has more cleaning additives than regular is by and large marketing hype, as is the idea that cars need more than the standard amount.