Hi all,

Was just wondering what level octane fuel you use on your petrol X-types. It obviously says to use "premium unleaded fuel only" but a man's got to save money when he can! Is it necessary to use the higher rated fuel, when the ECU probably can detect lower octane levels and "adjust"?

What level fuel do you use and why? I normally use 89 octane

Thanks in advance!

 

Jagtype, this has been discussed on multiple occassions and the short of the story is that some cars will handle the 87 octane gas and while others will accept nothing but 93 octane. What car do you have? There is no year difference, no 3.0L vs. 2.5L, vs 2.0L engine difference. Some cars just seem to handle the lower grades better. Kinda like some people notice a difference in mileage when they change grades of gas (ie, get better mileage with the higher grade gas, lower mileage with the lower grade gas) while others see no difference.

As for me, I am religious about using 93 octane. Granted, some times, if I can find something a bit higher, I run that. Why? IN short, someone a lot smarter than me figured out how to program the engine and they programmed it around 93 octane gas, so, why should I not trust what they say? Could I run a lower grade gas. Probably. Would the car run fine, most likely. But, what could it cost me if I have one of those cars that hates the lower grade gas? For the $4 a tank full extra that it costs, it is good piece of mind for me.

 

Excellent summary. That's it in a nutshell.


This is the first I've heard of this being done on a (modern) Jag. Do you have more details?

 

It's a gasoline x-type sedan. So then, with a stock ecu, probably should be using premium fuel then? Because I assume Jaguar set it that way

 

Jaguar suggests using 91 AKI fuel. As Chris pointed out, using 89 or 87 may/may not affect performance and fuel consumption.