So, in Colorado, regular gas is 85 Octane..and I'm wondering if I should be using 87 instead ( as recommended by Lexus ) ?

Just curious..

Vehicle : 2015 AWD

 

Never seen 85 octane offered for sale here in North Carolina and prior to reading this thread did not know it even existed. Is Colorado able to sell it due to the higher elevations?

 

85 octane is offered in the mountain states due to the higher altitude containing less oxygen. I saw it when I used to live in New Mexico. I recall they offered 3 grades of gas and all were lower octane than seen at lower altitudes.

 

We live in Calgary, AB and it's a high altitude city as well but never seen 85 Octane in the last 20 years!

I personally wouldn't use 85 octane although it's worthwhile to write to Lexus Technical office and discuss this matter in "writing". All the contact details are here.

 

You will be fine using 85 octane if you don't plan to visit the lower elevations. There isn't enough oxygen in the air at higher elevations to worry about detonation and pinging, which is the primary reason to use higher octane.