In my area I can buy both 91 and 94 octane. 94 is the highest octane available. Which would be the preferable grade? This is for a stock engine.
Thanks in advance.

 

IN my area the difference between 91 and 94 is 3 cents... its a no brainer.... I would rather have more octane then less octane.. because under certain conditions load, heat, compression change due to carbon build up, barometric pressure the need for more than 91 octane is a fact... knock sensors will protect the engine but you will loose performance and fuel economy .. its a case of Id rather have more octane so that when I need it , its there , then to need more octane and not have it...
even if its 10 cent a gallon difference you are only talking $ 2.00 a tank. If 2 dollars is a problem, then you have more serious problems then owning a Corvette....

 

When I was in California I could only get 91 Octane and car ran fine but would have been happier with 93 octane (which I have now).

 

The car would like 94 better, but make sure you buy it at a gas station that gets a lot of business. Fewer people buy 94 compared to lower grades so the 94 octane tanks might not get turned over as often, so it may not be as fresh.

 

Unless your engines pings when you use regular, there is zero need to use higher octane gas, unless you just have extra money burning a hole in your wallet.

http://www.kbb.com/car-advice/articl...-when-and-why/
http://www.cartalk.com/content/premium-vs-regular-1
http://www.consumer.ftc.gov/articles...ctane-gasoline
http://oppositelock.jalopnik.com/the...ter-1487358722

 

Tell me how anyone would know if their car goes into KR ? the second the knock sensors detect vibration ( micro second ) the timing is retarded loss of advance brings with it reduced performance, and loss of fuel economy...
the idea of not using the right octane is a 1960 argument..
A C5 runs hot.. its designed in.. its designed in to produce a 200,000 mile motor design. The first V8 in the world to shoot for this bench mark
why would any forward thinking person want to save 2 dollars a week, and put their car into a poor performance and poor fuel economy condition..
Lots of these car have produced enough carbon build up to increase the compression ratio.. If 2 dollars a week is a concern you should not own a High performance car... its a sad scenario when unqualified people push their thoughts on people, when the obvious thing is to weight the cost verse the results... why would anyone want to put their car in KR just to save a few pennies. when the few pennies saved will cost you in poor fuel economy... and poor performance.. I wont even go into the effect of KR and the hammer that effects the rotating mass when the engine knocks.. Run insufficient octane, long enough and it will knock years off the engine life. And for what ? to save 2 dollars a week? Seems fairly stupid to me, as a Corvette design engineer. When prevent KR protection is available at the pump and for a few cents more, you have to be a fairly cheap person to deprive your Corvette the best possible fuel available.. Don't bring up the owners manual.. Politics has a lot to do with that.
No argument here.. just my experienced opinion... I don't care what anyone else uses in their car.... I use the highest octane I can find.
I wont add further to this thread in open forum, but.. if anyone want to chat about this.. you can always PM me...

 

I'm with ya Evil-Twin. I stopped using 94 (to 91) in my 325i after turning it into my winter car this year (gauge issues making it unsellable for now), but I wouldn't dream of using anything other than the best available for my Z06. Why would I? How much would I save a year? For what?

 

Run what is recommended - -91 or higher from a top tier brand.

I've owned 12 Corvettes and always run the best octane I can find at a busy station - - -Shell, Chevron, 75/Phillips66 or QT.