Abdulaziz Alj

Hello, I've received my Cayenne today, the delivery guy told me that 98 octane fuel is "necessary" for the engine and using lower octane fuel such as 95 for long period will drop the warranty eventually, I want your opinion on this matter. both on best fuel and the claims he made about warranty.

alpine-al

RON 98 (or RON + MON 93 in the US) is necessary according to the owners manual. Does your owners manual have a similar statement?

dasams

Per the manual, the recommended fuel is min 98 RON/ 88 MON (93 CLC/AKI). 93 is becoming harder to find and in CA most stations sell 91. In case of an emergency, the engine is designed to run with fuels as low as 91 RON/82.5 MON (86 CLC/AKI) but do not floor the accelerator.

Abdulaziz Alj

Yes the exact statement also on the gas door (98 octane or 95)

Abdulaziz Alj

I'm in Kuwait so the 98 cost around $50 for full tank according to my calculation, but it is not available on all stations as it considered "ultra premium" yet the 95 octane is available almost everywhere and it is cheaper $31 for a full tank.

s85b50

My quick calculation shows for $0.8/L You spend $400 for 5000 km driven. That's $160 difference per 5000 km for you. A brand new engine will cost at least $15,000 plus installation labor, so the math is clear.
Do yourself and the car a favor and don't cheap out on the quality of fuel.

Abdulaziz Alj

You're right and thanks for pointing the difference, i know the 98 here is cheap in Kuwait considering the rest of the world but i'm sure owners from other countries will find it expensive, what i really wanted to know is do you guys also use the 98 octane or 95 or lowers as well

dasams

As I wrote above, in California nearly all stations sell 96 / 86 which is labeled as 91. Some is true in other parts of the US so there are many people running 96 without any issues. I think 95 should also be fine. All US stations also sell cheaper, lower octane gasoline but I’ll never put that in our cars.

s85b50

Cars optimized for 98 RON will run well on 98 RON and will not run at optimal condition with anything lower than that. Simple matter of design capacity.

Modern DMEs are capable of adjusting timing advancement(advance for higher octane /retard for lower octane), but this depends heavily on knock sensors which it detect pre-detonation in every combustion cycle and compensate for lower fuel by adjusting timing. You can imagine this does not mean 100% prevention of an engine knock as sensors have their delays. This is why the manufacturer will not honor warranty when a user decides not to follow their recommendations.

s85b50

This is precisely why users with high compression NA engines tune their DME to run best at 91 octane instead of the factory 93 octane in California. Performance wise, 93 octane prevails. Engine health wise, DME optimized for 91 octane wins.

Abdulaziz Alj

this is the recommendation to 98 octane in the manuals, the numbers changes here might confuse others (and me) i though octane measurement is international but the US might be using different measurement, honestly i only know octane idk about RON or MON