2017 Escalade/Denali L86 "requires" 93 octane - your experience?

[RobH]

The 2017 Denali and Escalade Owners Manuals say

"Fuel (L86 6.2L V8 Engine). Use premium 93 octane unleaded gasoline in your vehicle. Unleaded gasoline with an octane rating as low as 87 may be used, but it will reduce performance and fuel economy."

I know that the engine computer can enrichen the mixture and dial back the spark advance to prevent knock with lower octane fuel. And that most driving is with moderate to low load with these engines anyway which reduces pre-ignition/knock.

My perception is that, yes, 93 octane has more energy per gallon and more knock resistance than 87 octane, but not enough more energy and gas mileage to justify the price premium.

Since I don't plan to operate the engine above 3,000 RPM or at higher loads practically ever, will running 87 octane pose a problem?

If I buy the 2017 with the L86 with 37,000 miles,
I would get the transmission fluid flushed, and,
A tune with the AFM delete, which means the engine would be running at lower manifold pressure in V8 mode with eight cylinders working than it does in V4 mode with four cylinders working. I've seen that on my ScanGauge II with my 2016 L83 by running in M5 which disables the AFM.

What are your thoughts and experience on less than 93 octane?

 

[B-train]

Mine says 87 is fine, but premium is recommended, not required. I think I've heard some spark knock a couple times in 100k, but it really runs fine on 87. I've trailered with it (2 Honda Foremans, some firewood, and a full load of gear).

I'd say if you are concerned, then use premium. I've only really ever used 87 in my 2008 as well. Currently I blend about 20% E85 with 87 to get an octane rating of about 93 (again, 2008 denali). It absolutely loves it, and the mileage isn't much different than on 87.

I've run a blend in my 2017 as well. No check engine lights or weird running. It actually really liked it for the first tank I did on a trip. (About 20% blend). I just don't drive it enough to get a daily driver record of it. But, with the miles my wife puts on with 87, we've never had an issue.

I think based on what I gather from your driving habits, you'll be just fine.

 

[B-train]

One thing I forgot to mention is that fuel octane requirements can be affected by elevation. Being that you are probably closer to sea level than the midwest and mountain states, it may have an effect.

I've never had to run premium on trips to coastal areas, but something to keep on mind. The opposite holds true in higher elevations where lower octane actually helps vehicles run better due to less available oxygen to combust.

 

[Marky Dissod]

Best answer I can possibly give:
depends on how you drive.
The more gently you drive, the more you can get away with using 87.
I said 'get away with'. That runs kinda parallel to what GM said:
"Use premium 93 octane unleaded gasoline in your vehicle."
"Unleaded gasoline with an octane rating as low as 87 may be used,
but it will reduce performance and fuel economy."

The harder your L86 plays, or works, the more strongly 91 or 93 octane is recommended.
If you ever tow or race or drive with verve, or haul lots of people and/or stuff, 91 or 93 octane.

Part II coming ...

 

[Marky Dissod]

Since you are getting your ecm tuned:
be sure to inform your tuner that you'll prefer 87,
except when your engine must work or play hard.

Every pcm and ecm since '99 has had 2 separate spark tables - High Octane & Low Octane.
To oversimplify, if your tuner reduces timing in the Low Octane table by 2 degrees -
or something along those lines -
that would make it even safer to use 87, than GM originally intended.

Also, a question?: Can the L86 make use of E85?
If it can, you'll lose some range, but you'll gain octane / knock resistance.

 

[Joseph Garcia]

I've never seen 93 octane specified in an owners manual as the preferred fuel to use, but apparently it does exist (I saw lots of 91 octane specified as the preferred fuel). So, I learn something new every day.

The 6.2 LS was designed to be a high performance/racing engine, and it was later adapted for use in high end large SUV trucks to give them something other than the 'heavy and slow' feel. For me, 91 or 93 octane fuel is most compatible with the design of the 6.2, and I had Black Bear Performance give me a tune that is based strictly on 93 octane fuel. Sure, it is a more expensive fuel to use, but if I was only interested in low net fuel costs, I'd leave my 07 Yukon XL Denali in the garage and only use my Honda Fit. Of course, everyone has their own priorities, and that is cool.

Can you safely use 87 octane fuel in the 6.2? Some very knowledgeable and respected folks above have indicated that this can be safely done, and I fully trust these folks. Hopefully, @RobH you now have some great answers to your question.

 

[Geotrash]

I have a different opinion on this. Lots of reports out there on the interwebz of broken pistons and damaged ring lands from running 87 in the 6.2L. The I Do Cars channel on Youtube has some spectacular 6.2L failures from running 87 under high power operation such as towing uphill. You might get away with it for a while, but you pays your money, and you takes your chances.

 

[M Stewart]

I have a '19 Tahoe Premier with the 6.2. I have 130K miles on her and she's been on regular unleaded most of those miles. I will typically use premium when I'm road tripping for the slight increase in performance and mileage. I wouldn't get either of these running around town so it's just not worth the extra cost over the years. I have had ZERO problems with anything in the engine or anything that could be attributed to the 87 octane. Service it properly and don't flog her at every stoplight and you should be good with 87 octane. Your results may vary...

 

[Eighthtry]

I agree with M Stuart. I and The Queen have a 2011 Yukon Denali XL with 208,000 miles on her. No problem with transmission ever or with the cylinder killer ever. It runs as brand new, including max RPMs in passing situations.

About 98% of my mileage has been with 87. No knocks that I ever heard, and that is something I am familiar with and can easily hear.

2% with 92 on trips that require a sizable amount of two lane passing. I started 92 in all travel for the first time at 190.000 miles It upped power considerably. I was fiat-footed surprised with that change. I had no idea it made that much difference. It still gets 87 around town.

This 208,000 miles is with no oil consumption, as in zero.

The Queen said new one, so she now has a 2023 Yukon Denali XL. It will be on the road for a few years. About to leave for a 30 day 4,000+ mile trip.

The 2011 is for sale if anyone is interested. It is in excellent condition, which includes the interior. The Queen maintains the car's looks. I am responsible for maintenance and repairs.

I suspect we will need to follow site rules for that.

 

[91RS]

I can guarantee anyone running 87 octane has spark knock that they either cannot hear because they don’t know what it sounds like or the ECM is pulling the timing so much to mitigate the knock and the cost of power. Why buy the 6.2L if $5-$10 extra per fill up to keep your engine safe is an issue? Just buy a 5.3L.