85 or 91 Octane?

[ajkochev74]

These are the only two choices at my Costco. Lots of folks say to get 87 and that we are wasting money on 91. What about 85? It is ether it or 91 at my Costco.

[sheekeebut]

I'm sure you can try a tank 85 and see what kind of effects without harm. At worst you'll either get bad mileage, bad performance, or both.

You sure it's not being measured with some other rating, like RON?

[why?]

get 85. I assume you are at a significant elevation. At heights 85 is just fine, because you aren't getting enough air to mix anyways.

[IllusionX]

I'm sure you can try a tank 85 and see what kind of effects without harm. At worst you'll either get bad mileage, bad performance, or both.

You sure it's not being measured with some other rating, like RON?


We don't use RON in North America. 91Ron translates to 85 here.

[ajkochev74]

Thanks for the replies. Yes, to the higher elevation question being in SLC, Utah. I've always been of the opinion to get the higher for better MPG and engine performance. My wife always bought what ever is cheapest. Her 2010 Rav4 has an average MPG display on the dashboard. After a month of using 91 and another month of 85. It really didn't change the average. Thought I'd check and see what the general consensus was here.

She'll be thrilled to hear she won the debate! However I do get a consolation prize in that I get to tease her with my stellar driving skills! I found I could always get the average to go up 0.1 just due to my driving style, even after a hour driving it!