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Discussion Starter #1
Just want to get feed back from anyone with regard to using 87, 89 or 92 premium plus in the Madas. Depending where you live these days, a 28 gallon tank can be pretty costly at the new feul prices. Dealers are indicating that the 305hp-5.6 Armada engine can handle 87 regular gas. That kind of scares me for knocks and pings in a high compression V8 engine. I can't imagine it would burn efficiently or give the same performance as the 89 octaine or higher. I just have not seen any info regarding the use of 87 octane. Does anyone know whether there is a recommendation to use the 87 octane fuel? Any feedback is appreciated.
 

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Fuel Info - 87 Octane Is Good At Sea Level

Hello and welcome. You might want to do a search here and also over at titantalk with the simple word "octane." There is a ton of data. There is clear consensus that 87 octane works just fine in our engines at sea level and when not towing a load. It probably will work fine at all but the highest altitudes. People towing, especially in the mountains are getting better performance running 89, 91 or 93 octane.

Our trucks have a "smart" ECU that has the capability of advancing or retarding timing based on octane content and engine load. Over at titantalk, some of the regulars there are really, really deep into engine tuning, engine management systems and all that. They have done a lot of testing and reported the results. It seems generally agreed that running premium fuel is not necessary unless you are at high altitude or pulling a heavy load.

The other possible use is on the drag strip or during performance testing. As best as we can tell the only difference between the engine output ratings on the Armada and the QX56, which has 10 more bhp, is the use of premium fuel in that vehicle. The engine and ECU are identical. Premium fuel in the Infiniti merely allows more timing advance. You can do the same thing by running premium.

To take advantage of the small increase in power (and big increase in cost), you have to let the ECU "learn" that it has higher octane fuel. That requires a little time, at least several pedal-to-the-floor runs where the ECU will be called upon to advance the timing beyond what it has been doing. It may take several days or a good part of a tank of gas.

And there are many who say (I'm one of them) that the increase in power from use of premium is only available under WOT (wide open throttle) conditions, unless you are at high altitude or pulling a heavy load. For most of us, that means you will get no real benefit from the extra cost.

My personal habit is to run regular most of the time. I do tow from time-to-time, and when I know I am going to tow, I'll try to plan ahead and switch to premium (or add as much to the tank as possible) a couple days ahead.

Do the search and reach your own conclusion. There are differing points of view. I offer mine here.
 

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I've been switching between 87 and 91 every month for 5 months.
It's made no difference in MPG or even noticeable perfomance.
We are lucky that we can use 87 with no problems. Damn gas is $2.65 a gallon right now for 87 and even more for 91.
 

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Discussion Starter #4
Hey, thanks for the reponse on the fuel octane question. The big Mada's gas tank earns lots of respect at the pumps these days with the current gas prices. Being able to use the entire range of octanes, I would say that's an another plus for owning the big boy for all it's capabilities with its great engine power. It also eases my thoughts regarding fuel costs for the long distant vacations trips planned throughout the summer months. Thansk again.
 

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Discussion Starter #5
Good to know I can switch whenever I may have to. I like being consistant with one or two fuels out of habit from yesteryear's cars. But if the gas reaches anything like $3.00 at the pumps, that might get me a little concerned. Just think - $84.00 plus for one fill-up. That will the time to start carrying spare cans. Regards.
 

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Which gas company do you guys use? For example, Shell, Chevron, Arco, or even Safeway/Costco gas? Are they all the same with the exception of fuel additives? Does anyone prefer one company over the other and why? Just curious since we're on the topic of fuel. I am really interested in knowing what you guys run. I have been using which ever is the cheapest. Here in Livermore, CA, Arco by my house has been the least expensive with Costco and Safeway running very close. Is 87 octane fuel ((r + m)/2) method) really the same from the different pumps? Thanks.
 

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I try to stick to the major brands, Exxon, Chevron, Texaco, etc. I put 87 in which is running 2.03 most places. HEB has it for 1.98, so finally the prices are coming down. I usually get around 390-400 on a tank.

Did you guys hear that Exxon had a 44% profit over the past year? Not only that, we have way more gas on the market now than a year ago, and yet the prices are higher.
 
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