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6.2 And Premium Fuel


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Alright now sure how it is down at sea level but here is a rough estimate:

 

 

Premium Fuel: 93 or 91 Octane = Premium

Mid-Grade: 89 or 87 Octane - Mid Grade

Regular: 85 or 87 Octane = Regular

 

 

Up here at 5280 ft above sea level, we have 3 choices. 91, 87, and 85.

 

91 is like 93 down at sea level

87 is like 89 down at sea level

85 is like 87 down at sea level

 

Now the 2010 Denali 403hp 6.2L V8 recommends premium fuel, but regular is safe? I'd like to know for the 2007 380hp 6.2L if this is the same requirement.
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I have a bit of a predicament with my 2011 Denali, and I would value some opinions on this...

 

I purchased a 2011 Sierra Denali 1500 with just over 11,000 km's on it about 3 weeks ago. When I bought it I didn't realize that it was supposed to run on 91+ octane. I didn't find out till I looked at the fuel door on it's first fill. This truck does double duty as my work and personal truck. With work I am provided with a fuel card that's only good for 87 octane bulk fuel.

 

My question: Is it safe to run 87 octane bulk fuel in this truck 100% of the time, or would you sell the truck? I tried to convince the powers that be at work that the cost of the premium fuel will be offset by the efficiency gains on running premium in this engine, but they wouldn't bite. My only option is to run 87 octane or sell it and buy something else. Could running 87 octane in the 6.2L ever cause damage, and could running 87 ever become a warranty issue? (it says in the manual that you CAN run 87, but 91+ is recommended)

 

Edmonton is at 2,192 ft elevation if that makes any difference.

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Plenty of views... anyone want to chime in?

 

I think I may have found a solution, although I'm not sure how suitable it really is. The DiabloSport inTune can apparently de-tune this engine from 91 octane and tune it for 87 octane. I'm not a mechanic by any means but will this alleviate the knock when running 87 octane, and is it safe for this engine?

 

All I really need is for this truck to last 5 years and hopefully still be worth something when I trade it in or sell it. I'm basically given an expense check every month from work that covers my truck payment and my commercial insurance, and am also provided with a gas card good for 87 octane bulk fuel. Essentially it's free for me to own and drive this truck. As part of this deal, my truck always has to be within a 5 year old window. What I really need to know is will this engine last 5 years on an 87 octane DiabloSport tune? I'll probably put 150,000km's on it in that timeframe. (~93,000 miles)

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I just bought a 2010 denali and 1st tank put 87, i know they recomend 91, but im going to use about 3 tanks of 87, then switch to 91 to see if i personally can see/feel the difference.

 

when i was looking for one i did a lot of research, and spoke to a few people with 07-09 denials w/6.2 and well over 200k one was at 270km and they all said they run 87. Im sure it will be fine if u ran 87, but i personally do not know, i will in the next few months.

 

My fuel economy the first day i got my truck (yesterday)

at 90km/hr on cruise level ground - 10.3l/100km (it actually was around 9.9 for a but but the slightest incline it increases)

110km/hr on cruise why - 11l/100km (+/-1-2l, because of hills and what not)

keep in mind i wasnt giving it a lot of gas, so this can easly increase!

 

we will see how things change as i drive it, im going to keep a log!

 

if you do the math:

 

95l x $1.20/l = $114

95l x $1.30/l = $123.50

 

so cost difference per tank is approx $9.50 +/- depending on gas prices. (those are the prices in southern ontario)

 

if you want to pm me and ask me how im running on 87 vs 91 (when i know) your more then welcome to.

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If the owners manual is suggesting premium than there doing it for a reason.

87=less power less fuel milage

91 or higher=more power better fuel milage

e-85=104 octane which maxes out power but fuel milage is worse than with 87 octane.

When I say more power I mean the computer will max out the timing (advance it).

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I wish. There is no E85 available in all of Alberta from what I can tell.

 

 

And probably never will be either. Just run the 87 octane and be done with it. At the absolute worst the truck drops into the lower octane spark table...... and if the gas is free you obviously don't need to give a damn about mileage either.

 

If you want to tune it get a real tune...... but not locally. Get one from an online US based source that tunes with EFILive ( just so you can go the autocal route) or learn to tune yourself and buy the software ( like I did).

 

Or you can sell the Denali and run a truck that will actually make you money instead of just covering the payments. My 05 grosses around $70000 a year..... and was a $15000 truck I bought 2 years ago. True I pay for my own fuel but it's honestly peanuts in cost of operating the truck. Unless your "company" requires it to be brand new ( or close to it) as some do. But then again for me I own the "company" so I don't have that problem, lol.

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From the Owners Manual :

 

Gasoline Octane

For all vehicles except those with the 6.2L V8 engine

(VIN Code 2), use regular unleaded gasoline with a

posted octane rating of 87 or higher. If the octane rating is

less than 87, you might notice an audible knocking noise

when you drive, commonly referred to as spark knock.

If this occurs, use a gasoline rated at 87 octane or higher

as soon as possible. If you are using gasoline rated at

87 octane or higher and you hear heavy knocking, the

engine needs service.

If the vehicle has the 6.2L V8 engine (VIN Code 2),

use premium unleaded gasoline with a posted octane

rating of 91 or higher. You can also use regular unleaded

gasoline rated at 87 octane or higher, but the vehicle’s

acceleration could be slightly reduced, and you might

notice a slight audible knocking noise, commonly referred

to as spark knock. If the octane is less than 87, you might

notice a heavy knocking noise when you drive. If this

occurs, use a gasoline rated at 87 octane or higher as

soon as possible. Otherwise, you could damage the

engine. If you are using gasoline rated at 87 octane or

higher and you hear heavy knocking, the engine needs

service.

 

It's up to you really. It's your truck so do with it as you please.

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For what it's worth, I run 87 in mine... all the time.

I've tried premium - that is 93 octane here in Georgia - and my fuel mileage did NOT increase at all.

I know that it takes a few tanks for everything to adjust, so I actually ran it for about 3 months.

I've also used 93 when towing, and didn't get any better mileage.

That was during that 3 month period, by the way...

Also, 93 octane is typically AT LEAST 30, sometimes even 50 cents per gallon here.

It DANG SURE ain't worth an extra $7 - $12 per tank!!!

 

As for me and my house? We'll run 87.

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The higher octane fuel isn't for better MPG's, it's for a properly running engine. With the compression ratio of the 6.2L in these trucks, Premium fuel is required for proper/efficient function. Running low octane fuel will drastically retard timing, cut HP/Torque and overall perfromance of the truck. Might as well buy a truck that requires 87 octane fuel if that's what you can afford to run.

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I got one? For the first 3 days with my 6.0 I ran 87. K know 91 is recommended. Could that have hurt anything or contributed to my misfire code?

 

Is running 85 in high altitudes good for an engine requiring 87 at sea level? I did that for a few weeks in Utah with the 4.8

 

Sent from my DROID RAZR using Xparent Red Tapatalk 2

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