sleepyone

I live in TX and have always run 87 octane until I went to work in eastern Colorado and western Nebraska where 85 octane is in the base unleaded with ethanol. To get the 87 octane w/o ethanol you pay 10 cents more. My truck is new and has the 5.0 with less than 5k miles. I have not had any problems with performance or heard any pinging. The elevation is between 3,500 and 5,000 ft. Is that why they offer the lower octane level in this region?

Wanted33

sleepy, we just made a run through your area, and I noticed that most all the station have the 85 octane. I stuck with the middle grade because I was too far from home, and didn't want to risk problems. My question was why, and what type vehicles call for 85. Doesn't make since to me. As far as your question I have no idea if it will hurt the 5.0L , or not. I know the manual calls for 87.

danielson780

Doesn't flex fuel run 85. A quick solution would be your truck came with a book. A book of information, usually stored in the glove box. I believe it is called an owners manual. A look in there may just solve your gas woes.

thekevin

Flex fuel trucks will run E85, way different than 85 octane fuel.

Stations of the Sun

The 5.0L V8 says "Flex Fuel" on the side decals, it states in the owners manuel that the engine is designed with the option of running 85 no problem

Chrisj

Its really not that hard to understand if you try. As stated, vehicles that are rated for FLEX fuel can run on ethanol pecentages up to 85%. The 85 in regards to FLEX has nothing to do with octane. Most of us run E10 (10% ethanol). E10 is usually found in 87 octane, 89 octane or 91 octane (all 10% ethanol) I would prefer 0% ethanol. I hear E15 is coming that is 15% ethanol.

Octane is simply a rating for the amount of energy in the fuel. 85 Octane gas is just lower octane than most of us run. Gasoline can be 0% ethanol, or it can be 10% or 15% and still be 85 octane.

frieed

85 octane is sold as the "Regular" grade of gas at higher elevations because the lower air pressure at high elevations effectively lowers the compression ratio of normally aspirated engines. With lower compression ratio less octane is required to prevent knocking. Unless you are running forced induction you will be fine.

sleepyone

Thanks, frieed! You answered my questions perfectly. Now this a** clown, danielson780, obviously did not care to provide a thoughtful response and just wanted to impress us with his quick wit. My question had nothing to do with e85 or my truck's flex fuel capabilities. I simply wanted to know why some regions offer 85 octane and others offer 87 as the lowest octane. My theory was it is based on elevation and frieed validated it with a short and thoughtful response. Danielson780's punk-a** response is just the type of stuff that turns people off from forums. I believe there is an active thread addressing this very issue.

I know if I had asked him this question in person he would not have responded in this manner, or he would have regretted it as soon as the words left his mouth. This isn't grade school. And to think he is a senior member on this forum. Sheesh.

Wanted33

Thank you sir. With this info. I can save a bit of money the next time I visit your beautiful area of this great country.

Howler

So the ecoboost and 85 will not play nice?