Fuel prices

[Talyn]

It's more refineries than the above.

 

[Captain O]

I appreciate the sentiment, but I prefer to protect the old machine. (I have put well over $13,000.00 into a machine I purchased for $4000.00) It is worth the extra 10 cents per gallon to reduce the wear on the engine.

You have to pay to play. It is worth it.

BTW. Jaguar insists on 91 Octane fuel:

Fuel Grade Requirement for a 2000 Jaguar XK8​

The 2000 Jaguar XK8 (V12) is designed to run on premium unleaded fuel of at least 91 ( R+M )/2 octane (≈ 95 RON), with 98 RON (≈ 91 ( R+M )/2) recommended for optimal performance StartMyCar+1.

Official recommendation​

Jaguar’s 2000 model vehicle care handbook specifies premium unleaded fuel. In U.S. terms, this is 91 ( R+M )/2 octane (also called 91 AKI), which corresponds to about 95 RON in many regions StartMyCar+1. Many owners and Jaguar sources also note that 98 RON (≈ 91 ( R+M )/2) is ideal for the V12’s high compression and performance characteristics StartMyCar.

Why it matters​

• Octane rating measures resistance to detonation (knocking). The XK8’s V12 has a high compression ratio and can be prone to pinging if fuel octane is too low Jaguar Forums.
• Using fuel below the recommended octane can cause loss of power, increased fuel consumption, and possible engine damage from detonation StartMyCar.
• Modern XK8s have knock sensors that will retard ignition timing if knock is detected, but this reduces performance and efficiency Jaguar Forums.

Practical notes​

• Premium unleaded in the U.S. is typically 91 ( R+M )/2; in the UK/Europe, “premium” is often 98 RON.
• You may use higher octane (e.g., 100 RON) without harm, but it won’t improve performance StartMyCar.
• Some owners report no noticeable difference between 87 and 91 ( R+M )/2 in real-world driving, but the V12’s design and Jaguar’s spec still recommend premium Jag-lovers Forums+1.
• Avoid low‑octane fuel (e.g., 87 ( R+M )/2) unless you accept possible pinging, reduced power, and higher fuel use StartMyCar+1.

Bottom line: For a 2000 Jaguar XK8, use premium unleaded 91 ( R+M )/2 octane (≈ 95 RON) or better, ideally 98 RON if available, to ensure optimal performance and avoid knock-related issues StartMyCar+1.