Our gas filler cap and the Owners Manual both state that we should use only "Premium Plus EN 228 at least 95 RON/85MON". We have interpreted that to mean that we should use US "Supreme" gasoline with an octane rating of "98" or higher.
Our gas filler cap and the Owners Manual both state that we should use only "Premium Plus EN 228 at least 95 RON/85MON". We have interpreted that to mean that we should use US "Supreme" gasoline with an octane rating of "98" or higher.
A 95 Road Octane Number (RON) and a 85 Motor Octane Number (MON) equates to the U.S. designation of a 90 Octane (R+M/2). This octane requirement is based on sea level conditions. At a mile high (Denver for example) the cars require about 2 points less. That's why you'll see 85 octane regular and 89 octane premium there. (The oil companies trying to save a bunch on blending costs). The reason is that a vehicle that is properly tuned to maximize power at hi altitude, will run a less advanced spark than at sea level. I'm not certain how turbocharging or supercharging will affect the hi altitude octane requirement.
What about the 2008 US spec models? Will I have to buy premium for those too? Somewhere I read the fuel requirement for the US Spec was regular. Can anyone clarify?
What about the 2008 US spec models? Will I have to buy premium for those too? Somewhere I read the fuel requirement for the US Spec was regular. Can anyone clarify?
The engine specs for the 2008 thru 2010 are the same. The EPA erroneously posted that the 2010 used regular fuel. My understanding is that the EPA has corrected this. The official words are still 'premium fuel'.
The engine management computer will adjust to work on regular (85 octane) gas. It won't hurt your engine.
You will notice less Horsepower and lower mileage when using regular.
If you use premium (like the manufacturer suggests) you will get ALL your Horsepower, and your mileage will be maximized.
I said it before. In my car, the $$ savings for using 85 oct. in not greater than the operating cost of using 85oct. over 93 oct. IE. it cost more to use the cheaper gas.
Not long ago we had a posting that an owner suffered burnt valves and valve seats with 20-something K miles. One of the things that happens with grossly retarded ignition due to low-octane compensation is an increase in exhaust gas temperature. Makes you wonder if that poster was running on 87-octane and cooked his head (and cat).
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