I have. I've done the "Experiment" comparing performance on 87 vs 89 many times and every single time I can tell the difference immediately. I'm sure there are some people who would not notice because it depends a bit on your driving style. The power flow is just smoother with the 89. With the 87 the engine controls are always on the ragged edge of "normal" versus "retarded due to sub optimum octane"... So the air/fuel map is always being dicked with when you run 87 and it just doesn't run quite as smoothly. They could have designed it for 87 and then you would not notice any difference between 87 and 89 but you also would not be able to get the extra power with 89. As the owners manual says, it was designed for optimum performance on 89 but you can run 87 if you want or need to.Lately I have been filling my Jeep (with the 5.7 Hemi) with 89 octane instead of 87. To me, I can feel (I think) the difference with the power and engine response. Anyone else experience this?
At 6500 feet the 85, 87 and 91 are all you need to be equivalent to 87, 89, and 93 at low elevations. A car the calls for 87 at "normal elevations", i.e. typical low elevation that the vast majority of people live at, will usually run fine on 85 at high elevations. If you are running an unmodified hemi the 87 should work ok and just like 89 would at low elevations. If you had a blower that would not be the case. I have seen some owners manuals that discuss this but most don't. Except for vehicles that need higher than 89 at low elevations it's less confusing to tell people to use the same 87 or 89 no matter what the elevation.Octane is mostly for knock purposes. I live in CO (6.5K elevation) and we're stuck with 85, 87, and 91. All research about 85 is old and I still have no idea why octane ratings aren't standardized across the nation. I've only seen one article where a vehicle manufacturer engineer said to stay away from 85 basically but there's no owners manual I know that specifically talks about high elevation states. I use 91 simply because it's not much more per tank in the grand scheme of things BUT I fully understand it will make little to zero difference in power or mpg...85 octane can eat my ass.
If you have found plenty of people with the same issue but no one seems to know how to fix it... maybe that means ..... no one knows how to fix it!!!! If no one knows they can't reply and tell you how to fix it. When you complain of others being rude while you are on a free system where people help for free and you are calling out everyone else because they didn't know the answer to your question. THAT seems rude.I'm not a troll, I ask one question and get plenty of views but no response at all. At least an acknowledgment of said issue.
I'm not knocking anyone, when someone needs help, I do my best to help them.
No reason to be rude about it bro.
It's just when you would expect someone to know the general answer someone would say something.
I've found plenty of people with the same issue, but no one says how they fix it. Just disappear. That's my gripe.
And I'm just stating that others have helped me, when expected others haven't. There was no dissing or intent there.