2017 Silverado 1500 6.2 using Regular Gas

[ForumUser]

Hi All,

 

Have about 35K on the truck.

 

Only thing out of the norm was the 8 speed transmission fluid fix.

 

Have been using only regular fuel - no issues - anyone else doing same?

[2018GMC]

Oh boy, here we go....

[newdude]

I'd avoid it like the plague.  That engine should be on 91 at a minimum.  93 is preferred by GM 2017 and newer.  11.5 to 1 compression in that sucker with 420hp.  The more octane the better.  I wouldn't WOT it on 87, ever.   

 

Should have got a 5.3 if you want to run regular. 

[Jacoby]

You’re fine on 87 but it will run better on 93

[Darksky]

To protect itself from detonation the engine may retard performance with low octane fuel. You might not feel it. I can tell the difference under hard acceleration. They literally tell you not to run low octane fuel in the manual. It’s your truck, have at it.

[kennerz]

I won't harm anything to run it. The ECM will compensate by pulling timing. That said don't expect 420 HP on 87, or the best mileage. From what I know they will absolutely kill timing on less than 91 (they don't run that great on California 91 either). So do whatever you want.

 

Just sounds like you might be one of those guys that knows more than the manufacturer and does what they like when it clearly states not to do that. I agree you can get away with this when you error on the side of performance (better gas, heavier quality oil, etc...) But when you go the other way to save a buck it usually doesn't work as well. 

 

As was mentioned this is not a 8.5:1 iron block TBI. It's in a much higher state of tune and has basic octane requirements, unless you don't mind it pulling out about 30 HP (see LT1 camaros tank on the dyno once they start to knock - ECM immediately adjust and doesn't begin to add back the timing till sometimes later drive cycles).

 

I would run 93 if I had access to it. They run soo much better with the right fuel.

Edited August 21, 2019 by kennerz

[JimCost2014]

No, paid for 420 horses, want to be able to use all of them with a happy engine.

[TXGREEK]

Why would anyone buy a vehicle with a high performance v8 in it only to feed it low performance fuel? Guess bragging rights to owning a 6.2 versus the lower powered 5.3


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[mikedeezxxx]

I run premium (91 octane cause CA sucks) in all my vehicles, dirt bikes, Razor. My 5.3L has only ever seen premium gas. People shouldn’t be buying V8’s unless they can afford to put good gas in it.


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[TXGREEK]

I run premium (91 octane cause CA sucks) in all my vehicles, dirt bikes, Razor. My 5.3L has only ever seen premium gas. People shouldn’t be buying V8’s unless they can afford to put good gas in it.


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I don’t want to offend anyone but I Agree, never met anyone that didn’t research something before they bought it, especially now a days. OP Asking this question is just ridiculous but, if asking due to financial issues I wouldn’t look to start budgeting your fuel cost, saving $5 per fill up really isn’t going to get anyone out of the hole, your debt to income will. Good luck, I’m out of here!


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[truckguy82]

On 8/19/2019 at 5:26 PM, ForumUser said:

Hi All,

 

Have about 35K on the truck.

 

Only thing out of the norm was the 8 speed transmission fluid fix.

 

Have been using only regular fuel - no issues - anyone else doing same?

You should not run 87

 

want proof? Buy an obd2 bluetooth dongle and use a diagnostic app on your phone. Just watch the knock sensor, we’ll wait to hear back

[kennerz]

Oh, and by later drive cycles - I mean that thing starts to knock, you may not see the total level of timing it had come back for some time maybe even a couple of tanks of gas.

 

These engines are designed not to self destruct no matter how poor of fuel you run, so GM was super conservative/cautious with the programming  so once you see knock it assumes you have poor fuel can run off of another set of low performance tables.  Doesn't come back till it slowly adds timing back a little at a time if there is no more knock. Torque management gets effected as well.

 

That's one of the reasons why you need a tune and to run the best fuel you can. There is a lot of performance left on the table stock.

 

good fuel is the best "mod". What I'm saying is you could at bolt on's and run 87 octane, vs running  say 93 stock, & I bet it will run better stock with good gas. That big of difference. 

[SierraHD17]

On 8/19/2019 at 3:26 PM, ForumUser said:

Hi All,

 

Have about 35K on the truck.

 

Only thing out of the norm was the 8 speed transmission fluid fix.

 

Have been using only regular fuel - no issues - anyone else doing same?

Yeah you and good chunk of buyers of the 6.2 lol.  It's fun with used trucks as its obvious which ones have had premium and which ones haven't.  The have nots make me generally lift the hood to see if there is a 6.2 in there or not lol.  Low octane spark table sucks pretty well all the fun right out of things. 

[ForumUser]

I'm confused - you note "which ones have HAD premium and which ones haven't."

 

First question - if driven normally, would you notice?

 

Second question - once you cycle a few tanks of higher octane through, how would you know?

 

Given the stated 425 HP on the 6.2, how much HP do you think you lose with 87?  10-20 HP?

 

If no damage is being done, does it matter, really?  91 Octane = 14.1 pounds per HP, and 87 = 14.8 pounds per HP.

 

 

[MaverickZ71]

Another consideration--around here, fuel suppliers/gas stations are cutting the additive pack ingredients (think detergents) they add to regular and midgrade fuel.  Noticed my truck running different and my GM service tech mentioned to me that the spark plugs were all carboned up (even extra) and I asked 2 gas station managers.  Was told they only add the all of the "good-stuff" additives to premium fuel now, since it costs a good 40-50+ cents a gallon more than their regular gas, and their profit margin is so thin on the cheap stuff.  And yes, those are "Top-Tier" stations.  [20 years ago, the same additives were put in all 3 grades of fuel, and mid-grade cost 10 cents more than regular, and premium cost 10 cents more than that.]  

Edited August 22, 2019 by MaverickZ71