85 Octane

69mach1-395 said:

Not sure you know what top tier fuel is ^
There is no mid tier...

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Not sure what you're referring to...

85, 87, 91

These are our options in Colorado.

Top tier has nothing to do with octane. There is top tier, and everything else. There is no middle or bottom tier.

nelson said:

It's about a 75c difference, so yeah about that per fill up.

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Surely there is not a 75-cent difference between your 85- and 87-octane fuel in CO??? I don't think the people in this thread are demanding you use the 91/93 super premium, just follow the manual and use the 87. Around here (central/southern Ohio), there is at most a 10-cent difference between our regular unleaded (87) and mid-grade (89).

So now your fill-up cost difference goes from about $11 to $1.50. A very small price to pay for peace-of-mind.

HISSMAN said:

Top tier has nothing to do with octane. There is top tier, and everything else. There is no middle or bottom tier.

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If one wanted to get picky over matter of semantics, sure whatever. But my point is our 89 has been replaced by 87. We do not have 89 octane fuel.

HISSMAN said:

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In all seriousness, that looks like nitrous failure.

when I bought a Lexus a long while back it was recommended to have 91, that was what was recommended. However I was also told by someone with very good knowledge of this situation that in Colorado it would not matter one bit if I ran 91 or 87, or even 85 for that matter. My Lexus got better fuel economy with 87 than it did with 91, and thats a fact. Dont forget we are at 5200+ feet in elevation. He showed me a manufacture report that detailed the problem of altitude and fuel octane performance results. Granted I do believe that 91 will give you better performance but using something other than that will NOT hurt you car. In Colorado like others have said we have 85/87/91...and race fuel if you can find it. I will say we never run 87 in motorcycles, we always run 91...these are high compression racing engines that can run all day at 13K RPM. So it does lead to a question about the 2018 mustang that now has a significantly high compression ratio.

The Mustang doesn't "require" a specific octane, it recommends it and that is a big difference as some engine management systems are specifically calibrated for higher octane levels and dont change.

If your vehicle requires midgrade or premium fuel, absolutely. If your owner's manual says your vehicle doesn't require premium but says that your vehicle will run better on higher octane fuel, it's really up to you. The cost increase is typically higher than the fuel savings. However, lowering CO2 emissions and decreasing petroleum usage by even a small amount may be more important than cost to some consumers.

The sale of 85 octane fuel was originally allowed in high-elevation regions—where the barometric pressure is lower—because it was cheaper and because most carbureted engines tolerated it fairly well. This is not true for modern gasoline engines. So, unless you have an older vehicle with a carbureted engine, you should use the manufacturer-recommended fuel for your vehicle, even where 85 octane fuel is available.

Here's some more information out there:

Engine management software connected to knock sensors took care of that. By the 1990s, your engine management system was sophisticated enough that even if your car had a premium fuel recommendation (we’ll get to why that’s italicized in a second), if there was a full tank of 87 octane in the fuel tank, the system could sense any pre-ignition, and could automatically retard timing to take full advantage of the fuel delivered.

You might not get the optimal performance or fuel economy that 91 octane could provide, but the car would run knock-free as long as you used a minimum of 87 octane.

Up until the last few years, just a handful of cars had 91 octane requirements versus 91 octane recommendations. High performance cars like the BMW M3 and the Audi S4 required 91 octane, and the engine management system was so calibrated toward high performance that running lower octane fuel was detrimental to the engine’s health. The current Corvette is also in this class.

The issue now is that more and more cars ordinary cars have premium fuel recommendations, and they’re typically not “performance” cars, but vehicles that are helping manufacturers move toward the 54.5 mile per gallon average fuel economy requirement in 2025. If you’re not running premium fuel, you won’t damage the engine, but you won’t realize the car’s performance or fuel economy potential.

Whew Im exhausted....

youra6 said:

Not sure what you're referring to...

85, 87, 91

These are our options in Colorado.

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Just google top tier fuel...we should all be using it.

69mach1-395 said:

Just google top tier fuel...we should all be using it.

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yep we got all these here...like everywhere else but like he mentioned we only have 85/97/91 and I think the debate was octane not Top Tier Fuels. Are you saying the octane doesn't matter? Glad to see Costco on there also since I use it exclusively.

Top Tier retailers include 76, Aloha Petroleum, Amoco, ARCO, Beacon, BP, Break Time, Cenex, Chevron, CITGO, Conoco, Co-op, Costco, CountryMark, Diamond Shamrock, Entec, Esso, Express, Exxon, Holiday, Kwik Star Stores, Kwik Trip, Mahalo, MFA, Mobil, Ohana Fuels, Petro-Canada, Phillips 66, PUMA, QT, Quik Trip, Road Ranger, Shamrock, Shell / Shell V-Power, Sinclair Standard, SuperAmerica, SuperFuels, Tempo, Texaco, Tri-Par, and Valero.

I just filter Gas Buddy to only show Shell, Chevron, Exxon, Mobil 1. Texaco is probably another I should also add to my list.

Does really well as far as only showing me the good ones.

obgod3 said:

Are you saying the octane doesn't matter?

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Of course not...see my earlier posts.

7thStreetJim said:

If it don't knock don't knock it!

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Did he state he was data-logging? If not, then this is bad advice.

youra6 said:

Not sure what you're referring to...

85, 87, 91

These are our options in Colorado.

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http://www.toptiergas.com/

Top Tier refers to detergency levels. TT gas has to provide cleanup on standard PFI engine tests (the Ford 2.3L is one of the key tests).

Thanks for everyone's contribution, a lot of you are assholes but that's okay because we're on the Internet and (most of us) live in this great country with free speech rights (woo! :ford.

I do use top tier fuel the question was more around octane ratings due to the altitude which I think we've sufficiently answered here. For the record I actually did search quickly but could only get threads about E85 which isn't what we're talking about here.

Hope you all have a great weekend and can get out on the road sometime, seems like my 5.0 might be stuck in the garage this weekend due to weather :(

I didn't see where anyone was an asshole.

HISSMAN said:

I didn't see where anyone was an asshole.

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You should hit up the eye doctor then. All I wanted was some factual based responses, not .gifs and videos and people insinuating I'm a moron because they've never lived at altitude. As I said though, well within their right to do so.