Save some gas money-Use 85 in hi Alt

[XterraVersa]

Most vehicle manuals say that if you are above 5000 ft, you can switch to 85 octane, but not the Versa.

Well I had been using 87 octane up to about 3 months ago. Since new thru ~ 23,500 miles I averaged 36.8 mpg. This last winter's formulation took a nose dive. 30-33 mpg down from 34-37 mpg the previous winter. (The EPA hammered Denver last year for air quality violations)

The past 3 months ~3,000 miles, I switched to 85 to see if there was a difference. No there isn't. I got the usual spring rise in mpg. In the ~3,000 miles of 85 octane I am getting 35-38 mpg, 36.5 mpg average.

The other change was switching from Shell to Sam's Club gas. Both are from Suncor in Denver. I went with Shell for the 87 because it was the cheapest & Sam's didn't sell 87. In Denver 87 is a blend of 85 & 91.

I have used the 91 octane from Sam's for ~90% of the 78,000 miles on the Xterra with no problems. Sam's is always 10 -15 cents cheaper than the Shell next door.

[VersaMG08]

I usually buy the 85 octane and purchase those octane boosters at walmart for a few bucks. I don't know how much cheaper it is, but it helps with my MPG. I've been averaging 27-32 MPG recently. I may have to opt with Super Unleaded to get the better gas milage that the Versa is intended for.

[XterraVersa]

The higher octane will not help your mileage. Save your money & stop using octane boosters (scam).

Octane is an anti-knock index. If your engine is knocking, the sensors will see it & enrich your fuel to air ratio resulting in lower mpg.

If the engine doesn't knock with 87, it is running perfectly. Using a higher octane is just sending 15 more cents per gallon to the oil man.

I did my experiment to see if 85 caused knock. Clearly it doesn't in my car. Your low mpg probably has more to do with your driving habits & routes than what grade fuel you use.

On my Xterra, I had to use 87 octane once because they didn't have the 91 octane. I got less than 9 mpg out of that tank. The knock sensor picked up a knock, turned on the SC bypass and enriched the fuel mixture. The following tanks with 91 octane were back to the 15-18 mpg.

[Bubs daddy]

Quote »I may have to opt with Super Unleaded to get the better gas milage that the Versa is intended for.[/quote]I don't know how these urban legends continue. This is simply not true.

As mentioned above, you are wasting your money by using higher octane fuel. High octane fuel will not make it any more fuel efficient or get better mileage.

[biggie]

Uhm, no 85 oct around here.

[XterraVersa]

Uhm, no 85 oct around here.

Thats why I said high altitude, +5,000ft. I live at just over 6,200 ft. I think that is higher than any hill..I mean mountain... in NC

85 is our low grade, 87 is mid & 91 is premium.

[illf8ed]

Mount Mitchell, NC has the highest peak of any mountain east of the Mississippi.

[Great White Versa]

Mount Mitchell, NC has the highest peak of any mountain east of the Mississippi.

"Mountain" ha Don't you mean the biggest hill?

[Great White Versa]

I'll second that. I've gotten some of my best mileage on 85 octane gas.