Hey Answer Girl -

Why is regular gasoline in Wyoming 85 octane? I have purchased regular at 87 octane in other states. If regular had 87 octane, I could save 10 cents a gallon, as my vehicle will not run on 85 octane gas.

- Jerry B. in Gillette

Clint Ensign with Sinclair Oil in Salt Lake City said the octane rating of gas can be lower in Wyoming because of higher elevation.

Denver may have the cool "Mile High City" nickname, but Casper and other areas of the Cowboy State would have done well with that name, too, as we're pretty high above sea level.

The octane rating is a measure of the resistance of gas to detonation in spark-ignition internal combustion engines. Because high-performance engines are more prone to detonation, they often require higher octane fuel.

In higher elevations, 85 octane gas offers the same performance as 87 octane gas at lower elevations. Although you may think your vehicle won't run on 85 octane, it could be that your vehicle won't run on 85 octane at lower elevations. For more information on the performance of your specific vehicle at higher elevations, contact your vehicle maker's customer service department.

Hey Answer Girl -

Which bank tower in downtown Casper is the tallest?

- Daniel B. in Huntsville, Ala.

The taller bank tower in downtown Casper belongs to Wells Fargo. The Wells Fargo tower is 177 feet tall, according to Tim Kugler, the bank president.

First Interstate Bank rings in at a close second. Mike Houston with First Interstate said building plans put the bank's clock tower at 169 feet.

Answer Addition

There may be some debate about the left turn lane on CY Avenue in Casper.

According to Jeff Goetz, public information specialist for the Wyoming Department of Transportation, state statute says the lane can be used "for making a left turn from or onto the roadway."

That means that while the lane is strictly for left turns, if people are turning left to get onto CY - the "merging" traffic - they have just as much right to the lane as those making a left off of CY.

Also: A stretch of Highway 85 in Laramie County between Meriden and Cheyenne clocks in (late) as the longest straight stretch of road in Wyoming at 19.351 miles straight.

Contact reporter Megan Lee at (307) 266-0616 or megan.lee@trib.com

Ask Answer Girl

Answer Girl tackles your questions about Casper, the universe and everything else. Submit your questions by email to megan.lee@trib.com, or call Megan Lee at 266-0616. You can also write to Answer Girl, Box 80, 170 Star Lane, Casper, WY, 82602.