2000 Mercury Grand Marquis in Saudi Arabia: Use 91 Octane, Not 95

For a 2000 Mercury Grand Marquis (4.6L V8) in Saudi Arabia:

Recommendation

Use 91 octane (Regular / "Super"). Do not use 95 octane (Premium / "Ultra").

Why

• Owner's Manual Spec: Minimum 87 AKI (US) ≈ 91 RON (Saudi/European rating).
• No Benefit: Higher octane resists knock only needed in high-compression/turbo engines. The Grand Marquis has moderate compression (~9:1) and no knock sensors tuned for premium.
• Potential Downsides: 95 octane burns slower/cooler—can reduce fuel economy, increase deposits, waste money.
• Cost: 95 octane is ~15–20% more expensive per liter.

Saudi Fuel Grades

• 91 RON = "Super" (green pump) – Correct for Grand Marquis.
• 95 RON = "Ultra" (red pump) – For high-performance/turbo cars.
• (98 RON "Ultra Plus" exists but rare.)

Stick to 91 (Super). Your engine, wallet, and emissions will thank you.