Been running on 95 for the best part of a month, bought the car and started a new job at the same time, so didn't really check things out.

I'm not very mechanically minded

 

I run 93 in mine, and if i remember correctly the minimum is 91. So you should be fine either way. There are a few good threads about octane ratings here on the forum. Here is one suggesting that higher octane may give you better performance (at least in the MPG category).....

https://www.crossfireforum.org/forum...91-octane.html

Do a search on octane rating or ethanol and you should find some useful information.

 

Thanks for the link!

 

Where are you filling up w/ fuel higher than 93 octane?

 

I use 87 a lot, no pings, time normal, gas mileage the same, toss in a couple of tanks of 91 or 92 and she runs the same.

 

Yeah, here in CT, standard pump grades are 87 / 89 / 93 with 10% ethanol. I don't think I've ever seen 95 octane advertised.

Also, the engine spec calls for 91 octane. Not sure there is any benefit to 93 let alone 95. Maybe with higher boost and/or advanced spark.

 

I guess he is not in the US, octane ratings are different in other countries.
I think he is talking of the equivalent of 91 and 94 octane.

 

Spain: 95 RON "Euro" is sold in every station with 98 RON "Super" being offered in most stations. Many stations around cities and highways offer other high-octane "premium" brands.

 

Are European cars running higher compression ratios than the U.S.? What's the benefit of the higher octane blends given that octane yields less energy per given volume than heptane? Emissions?

 

What 180 was talking about is different ratings (same gas). Europe is RON, and we are (R+M)/2, or the difference between RON & MON. Check out Wikipedia.

 

From the BP website....
attached image
Also interesting what they add about ethanol, since it contains the OH group (being an alcohol) it provides oxygen through this OH group....

"......This is BP Unleaded 91 with up to 10% ethanol. Because ethanol has a higher octane the addition of ethanol increases the octane to 94 typically so potentially there are economy and power benefits. However because the ethanol contains oxygen there can be up to 3% reduction in fuel economy to offset the power....."

I'm not sure the OH group really adds to the thermodynamics - since it will ultimately sop up H atoms to form H2O in the end (exhaust).
What I'm trying to say is....the fact that it "adds oxygen" is possibly a misnomer, since it adds OH, but this doesnt participate in breaking C-H's and making C-O&C-O2 where your main hp (enthalpy) gains are made.

I run Ultimate or Shell's equivalent V-Power in my cars - interesting read though.