Octane conversion based on Altitude - DodgeForum.com

Go Back  DodgeForum.com > Dodge SUVs > Dodge Durango > 1st Gen Durango
Reload this Page > Octane conversion based on Altitude
1st Gen Durango 1998 - 2003 Durango's

Octane conversion based on Altitude


Old 05-21-2011, 11:25 AM
Kensai's Avatar
Kensai is offline
Thread Starter
Join Date: Dec 2003
Location: Dallas, Tx
Posts: 2,628
Default Octane conversion based on Altitude

Okay, question for those that are very knowledgable about octane ratings.

Let's say, I am currently using 93 octane in low altitude areas like DFW. I drive up to Denver where the alttitude is very high. What would the premium octane equilivient be? I don't want to reprogram my RT back to 87 which is considerd mid grade in Denver. Denver's regular octane is 85. Their premium is 89 octane.

Can I run with 89 octane as premium fuel while driving in very high altitudes?

Dunno how the PCM would interpret the lower octane fuel even if it knows it is now in high altitude.
Reply With Quote
Old 05-21-2011, 04:45 PM
hydrashocker's Avatar
hydrashocker is offline
Hall Of Fame
Join Date: Jun 2005
Location: GJ, Colorado
Posts: 14,216

If you are using a 93 octane tune on you tuner and want to leave it with that tune then you only need the top grade fuel which at around 3000 elevation changes to 91 octane.

93 octane at sea level is the same fuel at lets say 3500 ft but only registers at 91 octane.
90 octane at sea level is the same fuel at lets say 3500 ft but only registers at 87 octane.
87 octane at sea level is the same fuel at lets say 3500 ft but only registers at 85 octane.


High grade "Premium" fuel is 91 here at 4500 ft.
Midgrade "Med" fuel is 87 octane here at 4500 ft.
low grade "Low" fuel is 85 octane here at 4500 ft.

If you are looking at grades on line, well some people call the best fuel Premium or Super, so it could be terminology issue. The numbers change because of altitude, not because the fuel is different and Denver has all 3 types so don't worry. In reality it's all about Government laws and Regulations that have to have a standard, that standard is at sea level, so the numbers are bigger but atmosphere psi's up here is lower then down there and that changes the number.

Reply With Quote
Old 05-23-2011, 11:28 AM
Compactc9 is offline
Join Date: May 2011
Location: Denver
Posts: 439

Out here in Denver our premium is 91, mid is 87, and regular is 85.
Reply With Quote

Related Topics
Thread Starter
Last Post
3rd Gen Durango
01-18-2016 07:34 AM
Dodge Ram Van
10-06-2015 11:15 PM
3rd Gen RAM general discussion/NON-tech
09-30-2015 11:27 AM
Dodge Caravan
09-29-2015 07:06 AM
Dodge Charger
09-13-2015 03:28 AM

Thread Tools
Search this Thread
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Featured Sponsors

All times are GMT -4. The time now is 05:28 AM.

  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: