85 Octane?

[tjbender]

Hey everyone, I just drove my 2009 Versa 1.6 sedan up to Denver and dropped it off with family, as my wife and I are moving up there in about a week. My mind was absolutely blown by gas pumps in New Mexico offering 86 octane, then pumps in Denver offering 85 as the regular grade.

I believe the Versa owners manual calls for 87, which is what I've always been using in the tank. My question is, considering the altitude difference between sea level and Denver (of, you know, a mile), would I be ok putting 85 octane into my Versa, or should I go for the mid-grade 87?

Also, I still have the stock Continental tires on my car, and while the sidewall says they can be run as high as 44 PSI, I'm wondering if that's a good idea. I'd been running them at 36 in San Diego, and (again, factoring for altitude) I'd like to run them between 40-42 up there for fuel economy purposes. I got a whopping 21 MPG between San Diego and Casa Grande (thanks, Valvoline, for being a bunch of lazy slobs and leaving my four tires at 30, 28, 27 and 26 PSI), then caught the tire pressure error and inflated them to 42 for the ride through New Mexico and Colorado.

Thanks for the help!

[Andrews Chalmers]

If you're going to be at high altitude for the entire duration of your tank - using 85 would be better. Otherwise stick with 87 so you don't get knock on the 85 when you're back to low altitude.

As for tire pressure - I run them at the recommended 33 PSI. For me personally - comfort, proper tire wear, and handling/safety is a bigger priority than the additional few % in fuel savings offered by running the tires up to the 40s.

[Fred Farkel]

The other problem running your tires at such a high pressure is that you will probably get uneven tire wear across the tread.

I don't quite remember but I think with the higher pressure, the center of your tread will wear out before the edges!

The 85 octane should be OK as long as you use the whole tank in that attitude.