Per the owners manual for a 2011 Mini Cooper:

" Required fuel

Super Premium gasoline/AKI 91

This gasoline is highly recommended.
However, you may also use gasoline with less
AKI. The minimum AKI Rating is:

>

> Cooper: 87
If you use gasoline with this minimum AKI Rating [87 Octane], the engine may produce knocking sounds when starting at high outside temperatures. This has no effect on the engine life."

So, if I use 87 Octane gas, and the engine heads later need repair due to the low octane fuel, why isn't this repair job covered under the warranty?
After all, I've been using gas which complies with the minimum acceptable AKI rating. If it's not acceptable or invalidates the warranty, then it should be stated differently in the owners manual.

It says right on the fuel door 91 octance. I realize what it says in ur manual.
Bottom line, your mini is designed to run on 91 octane with top tier gas.
Dont use low grade gas from costco, cub fuel express, or your arabian mart down the road. Holiday, sa, bp all use good detergents.
Your only saving a dollar or 2 at the pump using 87 or 89, so dont short out on ur mini. All minis with the high pressure injection (o7 and newer) need to use this gas. Misfires and rough running will occur overtime if not.

I fully agree with using the recommended fuel (91 octane top tier) - no issue here. However, the question in my post about warranty coverage for engine repairs remains unanswered.

When your vechile is out of warranty, it is out of warranty, 4 year 50,000. I recommend an extended warranty for sure. Any issues that come up due to poor fuel quality is yoru responsibility.
It is about a 5 hour job to remove intake manifold, (just labor) clean your intake valves and perform a fuel injection cleaning to remove all the carbon/raw fuel deposits that accululate in your intake runners and intake ports of the cylinder head. I see it all the time.

We are being told by the dealer that my wife's mini has carbon build up. She has always used high octane gas since she bought it new. Now they are telling her that the gas stations she has used do not have good grade gas. I smeel a RAT. They just do not want to admit they have a problem with carbon build up and the design of their engine. I welcome any comments from other mini drivers that have had this problem. She has about 79,000 miles and most of that is free way miles as she does long commutes to and from work