2017 Silverado 1500 6.2 using Regular Gas

diyer2 · August 23, 2019

2 hours ago, ForumUser said:

Actually, I’ve been asking if others are using regular exclusively, looking to determine if there are negative side effects.

To the mileage difference point ... yeah, if there was a 10% difference in mileage, I might consider premium ... anyone had this experience? I mean, actually tested multiple tanks over time, etc? I’m assuming the results would vary by city vs highway driving, but might be instructive.

And, I also shake my head when others mistake questions and the process of obtaining information as being hard headed or inexperienced ... simply because I don’t immediately accept their positions.

BTW, I don’t find anyone’s position on this sort of stuff mind boggling ... sometimes they're smarter than me, sometimes their experiences are simply different, and sometimes we’re inevitably talking about different subtleties in the topic.

OK

kennerz · August 23, 2019

18 hours ago, ForumUser said:

I realize the 87 vs high octane discussion continues .

I’m getting suitable performance from the engine with 87 ... if it isnt being damaged, and the manufacturer allows 87, why would I spend 20% more on fuel?

Here in the red state the cost differential is more like 10% so between increase mileage it's a wash. The truck will just run noticeably better. I experimented with this a little when I 1st got my truck and the difference to me was immediate. Went back to premium fast.

There are many reasons why we have trucks so it's cool that everybody has a different purpose of use in mind and budgetary restraints. My $.0003 perspective it I like my stuff to run and feel right. makes driving a lot more enjoyable to me - so set up, tuning, right combo of part, etc … all matter. Anyone who has the privilege of driving my vehicles or buying them if and when they get sold receives the benefit of all the care, research and attention my vehicle receives and feels this the moment they get behind the wheel.

Stuff feels way beyond what it did off the showroom. And part of that is running the proper fuel. I have a friend who is a mechanical engineer who worked in R&D for all the OEM's both Japanese and domestic (is a subject matter expert in both hybrids vehicles, and all forms of motorsport) and one of the biggest things he drove home is fuel quality and to always use the best you have available. Only "unless" it's a low performance application do you do otherwise (like lawnmower, prius, weedwacker). This guys has tons of real world experience, failure analysis, and empirical data with emphasis on fuel/combustion theory. No joke.

SierraHD17 · August 23, 2019

4 hours ago, ForumUser said:

Just bumped into an article on 2020 6.6L direct injected engine without AFM/DFM (supposedly because so many owners don't like) ... GM still trying ... we'll see if the direct injection offsets the AFM/DFM savings.

Gm didn't choose not to install afm or dfm because owners don't like it lol.. It's because the HD truck market doesn't have the same EPA requirements of the light duty market and therefore it's not required. Look at the trucks themselves.. tall body, big mirrors and lots of ground clearance... and thats just the little guys. This engine is for cab and chassis trucks as 4500, 5500 and beyond series trucks. You think a guy buying a box van with the aero of a house cares about some fuel saver tech that would never engage anyway... or a motorhome... or a deck truck? These aren't a let's install afm to maximize economy design for a truck. What is required is a robust setup designed for heavy loads its entire existence and plenty of wide open throttle. Maximum possible highway fuel economy isn't really big on a fleet buyers radar but reliability and little downtime is. They don't build the 6.6 for Joe Schmuck and his twice a year holiday trailer adventures... that sale accounts for so little of the gas engine HD sales they could not care less. Afm or dfm play no part in that equation so they won't install it. If they start pushing fuel economy regs on the HD trucks like they do with the half tons I am sure they will install it at that time or some other nonsense... that is if they can make it pass endurance testing which would not surprise me one bit if they couldn't with afm or dfm. The L8T is an HD truck exclusive.

ForumUser · August 23, 2019

Sorry - pulled info from this article that mentioned preferences of the consumers ...

http://gmauthority.com/blog/2019/02/new-gm-6-6-liter-v8-l8t-engine-no-active-fuel-management-auto-stop-start/

It's interesting to see it is regular fuel recommended ...direct injected, 401 HP (24 less than 6.2), 464 torque (about same as 6.2), 10.8 compression ratio (vs 11.5 in 6.2)

Extra 0.4 liter displacement is in 6mm longer stroke ...

MOST interesting is iron block!

SierraHD17 · August 23, 2019

Pathetic timing curve is why there. It's no different than the L96 6 liter its replacing. Even moderate timing increases on the old 6 liter make it start having knock retard on 87 gas. And stock wide open throttle is at best 17 degrees or so lol. My 17 has up to 30 degrees in it now for reference sake lol.

I expect maybe 15 degrees of advance on the 6.6 to account for the loads its required to see and 87 octane fuel. Direct injection is allowing for the compression ratio it has but like the 5.3 it's going to be neutered from the factory. Numbers are still pretty good knowing these facts. Would not surprise that with tuning and premium or e85 you would be able to bump up the horsepower and torque on that 6.6 by a good 50 points for each with no other changes. Have to see what cam profile it uses but its going to be mild. This is all basing it on you being able to tune it with the ecm they are using with it... which is questionable. I plan on getting a 6.6 soon to play with but just the engine and not the truck. If I can make an e92 controller work in my 2017 HD that's where it's going lol. Gm and interchangeability is always something nice lol.

And for reference sake all that article says is its noteworthy GM didn't install the afm or dfm stuff with all the issues the systems have had... that has nothing to do with GM or why they aren't using it and is just that sources opinion. The 6.6 doesn't need it nor would it be actually useful in most instances of what the vehicles it will be placed in get used for.

TXGREEK · August 24, 2019

I unfollowed this topic but keeps popping up. So I’m Curious, did you know anything about the difference between the 6.2 and 5.3? If you’re worried about spending $5 more at the pump why did you buy the 6.2 instead of the 5.3? I’d assume you either didn’t know the 6.2 preferred high octane or you payed extra for the 6.2 just to have the bragging rights? Something just doesn’t add up, actually this is why I NEVER buy used vehicles, always someone out there that neglects something nice until someone buys it and later complains about motor issues, ends up in these forums complaining about GM trucks. Hopefully you do proper oil changes with what’s required synthetic 0w20. Lord help the next owner, make sure you tell the next buyer exactly how you took good care of it.

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ForumUser · August 27, 2019

Txgreek,

You went from asking a question ... yes, I did know it preferred premium, and I also knew what that meant. This combo gave me some options, so I bought it.

Then, you infer neglect, in this case, by not using premium fuel - which is not required.

You then note I should tell the next owner I used an allowable fuel?

Guess it’s time for you to unfollow, again ... sounds like the facts may be causing you undue angst.

TXGREEK · August 28, 2019

Txgreek,

You went from asking a question ... yes, I did know it preferred premium, and I also knew what that meant. This combo gave me some options, so I bought it.

Then, you infer neglect, in this case, by not using premium fuel - which is not required.

You then note I should tell the next owner I used an allowable fuel?

Guess it’s time for you to unfollow, again ... sounds like the facts may be causing you undue angst. [emoji846]

Combo, what combo? You just admitted you knew it prefers premium when you bought it. Ever think to look into it, why does it prefer premium fuel? It’s a high performance base motor and you’re on a forum looking for complete strangers to tell you it’s ok to use cheap gas in it, wth!

Guarantee you that the dealership will 100% figure it out as soon as you bring it in for knocking or other engine related issues causing you Undue Angst.

Btw, flex fuel would be considered a combo, not using cheap fuel in a performance engine.

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ForumUser · August 28, 2019

Sigh ... the engine is approved to use regular fuel by the manufacturer and by extension this is known by their dealer network ... right? It was designed this way.

Sooooo ... what are you so excited about?

Performance engine? Nah.

I would like to hear other owners’ experiences with regular v premium, though ... vice shrill warnings of impending doom.

KARNUT · August 28, 2019

I would consider it a performance engine. My wife’s 195 Horsepower v- tec engine in her Acura is considered a performance engine requiring premium fuel. You can find cheap gas at a no name fuel station too. I wouldn’t do that either. Not wanting to put premium fuel in the top gas engine in an up model truck is puzzling to me.

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ForumUser · August 28, 2019

Wow - didn't take you long to get nasty ... when someone disagrees with your incredibly flawed logic.

Hopefully your friends know this about you and will mitigate your attempt to influence them.

Now, if you had some data (ya know - studies, analysis, etc) - vice opinion, it might mean others will listen to you.

I'm still stuck on this, though ... "It’s already been explained how it could be causing damage to your engine leading to failure" - odd how and why a manufacturer would not warn of this?

So, getting past your input, are the owners of the 6.2 that have been using regular and have some information to contribute to the discussion?

JimCost2014 · August 28, 2019

8 hours ago, ForumUser said:

Wow - didn't take you long to get nasty ... when someone disagrees with your incredibly flawed logic.

Hopefully your friends know this about you and will mitigate your attempt to influence them.

Now, if you had some data (ya know - studies, analysis, etc) - vice opinion, it might mean others will listen to you.

I'm still stuck on this, though ... "It’s already been explained how it could be causing damage to your engine leading to failure" - odd how and why a manufacturer would not warn of this?

So, getting past your input, are the owners of the 6.2 that have been using regular and have some information to contribute to the discussion?

So, I realize it is your truck, your money, your decision, but my hopefully logical question is:

How many miles do you drive a year, how much do you calculate that you are saving buy running the lower octane gas?

Is it really a substantial amount to risk possible damage (not known for sure, but possible)?

I know that a machine will not last forever, but I personally do try to adhere to the manufacturers recommendations, or even use better quality fluids, gas, OEM replacement parts, etc....

Once again, not a slight on you, or your decision, just curious why you chose that path.

TXGREEK · August 28, 2019

8 hours ago, ForumUser said:

Wow - didn't take you long to get nasty ... when someone disagrees with your incredibly flawed logic.

Hopefully your friends know this about you and will mitigate your attempt to influence them.

Now, if you had some data (ya know - studies, analysis, etc) - vice opinion, it might mean others will listen to you.

I'm still stuck on this, though ... "It’s already been explained how it could be causing damage to your engine leading to failure" - odd how and why a manufacturer would not warn of this?

So, getting past your input, are the owners of the 6.2 that have been using regular and have some information to contribute to the discussion?

Don’t destroy your 6.2 to save a couple dollars at the pump. Everyone knows that a high performance motor requires high performance fuel in order to get the full potential HP, Torque and MPG’s out of it.

http://www.duramaxhub.com/gas/gm-6.2-ecotec3-l86.html

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Darksky · August 31, 2019

On 8/28/2019 at 2:28 PM, TXGREEK said:

Don’t destroy your 6.2 to save a couple dollars at the pump. Everyone knows that a high performance motor requires high performance fuel in order to get the full potential HP, Torque and MPG’s out of it.

http://www.duramaxhub.com/gas/gm-6.2-ecotec3-l86.html

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Or do.

What does anyone else know that you don’t?

The psi range on tires is only a recommendation as well.

Hose water works just as well as “big windshield washer” would have you believe their wiper fluid does.

I wear plastic bags on my feet instead of those expensive socks. I mean, I don’t save a whole $300 a year. But, it don’t hurt nothin’ and every bit of savings counts.

Jacoby · August 31, 2019

As I said before. You’ll be fine on 87. Performance will be degraded but you won’t harm your engine. The engine will “detune” itself to prevent any harm.

But I got to agree with others. The price difference is minute so I would run premium in it but that’s just me.