I live at 8500 feet, and after coming from chicago I can feel a huge loss of power. This is of course expected with the standard math saying 3% loss of power per 1000 feet meaning about a 25% power loss. I'm already using the local regular gas of 85 octane which helped....a little.

So, has anyone seen a power tuner that addresses this? I talked to Bully dog and they said theirs is not custom tunable. Since you can go down many octane ratings at altitude, I figured I could perhaps run their premium tune on regular to average out the difference, but they wouldn't officially say that is ok or not, which I understand they really can't do. Any thoughts on this?

Anyway, any experience with this problem anyone? this is the 4.7, not the hemi. I used to think this truck was fast. not so much now.

And just to prevent the flame war here that happened when I asked this question in another forum about my other car, I would like to say: If you don't understand what happens at altitude or why you can use lower octane or advance your timing at altitude, nothing personal, but please keep thoughts to yourself until you have the technical understanding to discuss this issue. It was quite a sh*tshow with those less qualified screaming "do what the manual says!". Hilarious, but sad.

Thanks in advance!

Conifer, Colorado for the curious.

 

I run the 93 tune using 91 octane, which is all we can get here. Yes I understand the altitude effects and why I can run the 93 tune with 91. BTW I am at 7000 feet. The altitude affects all others the same here, but the turboed guys have an edge. While my tune only adds 35 crank HP or so, going to sea level will add about 125HP! Not much we can do up here guy, grin and bear it. BTW, I only run a 15.1 second quarter up here

 

Thanks,
As a further question: do you think you could run 89 with that premium tune? how about 87? 85? Just as a point of argument, wouldn't it stand to reason that at some higher altitudes you could go even lower on the octane? not just safely, but with benefit? (I'm not thinking about saving pennies, I'm thinking purely of the burn.) Or even lean out the A/F ratio since the burn isn't so complete up high? I understand no one, including me, wants to be that guinea pig to detonate their engine by trying lower octane, but it really seems reasonable to me that at certain elevation ranges an appropriate lowering of octane could be beneficial. I've tried but can't find solid math for this anywhere, but I know it exists!

 

For me personally, I never run anything less than 91. It may well be that an even lower octane could suffice for us in the clouds, or even benefit us, but it gives me peace of mind and I have had zero detonation issues. For a few pennies I consider it cheap insurance and peace of mind. I tried the 87 or 89 tune and frankly I could barely discern any difference from stock. The 93 tune was night and day. So yes you might be correct in that one could get away with the lower grades up here, I just haven't the courage to try it.

 

So I'll be the uneducated one here. So from what I'm reading above, I can run the Superchips 93 tune using 91 octane since I live at ~ 6500-7000 feet and it'll actually run fine??? Thanks

 

if a tune is meant for "premium", then whatever the local premium rating, is you should be fine. I'm questioning if you could even step it another notch down at even higher altitudes. Denver is at 5200 and they knock off two points from 93 to 91, so is it sound logic to go down to 89 at 10,400 feet?