Here in Wyoming and most of the Rockies they sell 85 octane as "regular" and 87 octane as "plus." I'm just wondering if it makes that big of a difference performance to justify the extra cost of 87 here at higher altitudes. (or since regular is $3.15 and plus is $3.25 should I even be concerned since most places are close to $4.00 from what I hear)

 

I honestly put in the cheapest stuff which is usually the 85 around here if you can find it. We are already at $3.85 and growing.. It was $3.95 on Friday and came down some, but we are bracing for the $4.00 in a week or so!

 

At higher elevations (and less oxygen) 85 octane = 87 octane.

Don't waste your money on 87.