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Running reg or medium grade fuel with the 6.2?

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Jordan18 Enthusiast

Jordan18

Posted
Posted

I accidentally ran regular twice in my 2011 6.2L and did not notice a difference. Maybe not the whole tank though and I was highway driving.

In my manual it says it is ok.

I will be running premium in my new one 100%

 

 

2011 Silverado manual

 

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 a

slight audible knocking noise,

commonly referred to as spark

knock, might be heard.

 

2015 Silverado Manual

 

If the vehicle has the 6.2L V8 engine

(VIN Code J), use premium

unleaded gasoline meeting ASTM

specification D4814 with a posted

octane rating of 91 or higher.

Regular unleaded gasoline rated at

87 octane or higher can be used,

but acceleration and fuel economy

will be reduced, and an audible

knocking noise may be heard.

 

Same here. Although the person I have been on contact at my dealer (commercial sales manager) says they have been filling ALL of their 6.2Ls at the dealer with 87 and that 91 is not required.

 

Filling up with prem has become the norm between me and my girlfriend (drives a VW Tiguan) and even in my current 5.3L which such high miles.

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gaudette Enthusiast

gaudette

Posted
Posted

I have no experience with the 6.2L but I will tell you that I ran 87 exclusively in my mercury marauder and it ran perfectly fine throughout my ownership. Bought it at 100k miles and sold and sold at 130k. I'd assume the technology in these newer trucks are exponentially better at compensating for lower octane fuel.

 

The reactions on the marauder forum were pretty much identical to this. Instead of answering your question and being helpful people would rather tell you it's a stupid question. I've yet to see any experimentation on this issue that provided accurate facts and not just opinions.

haider320 Enthusiast

haider320

Posted
Posted

I have no experience with the 6.2L but I will tell you that I ran 87 exclusively in my mercury marauder and it ran perfectly fine throughout my ownership. Bought it at 100k miles and sold and sold at 130k. I'd assume the technology in these newer trucks are exponentially better at compensating for lower octane fuel.

 

The reactions on the marauder forum were pretty much identical to this. Instead of answering your question and being helpful people would rather tell you it's a stupid question. I've yet to see any experimentation on this issue that provided accurate facts and not just opinions.

I doubt your marauder had a CR of 11.0:1.

haider320 Enthusiast

haider320

Posted
Posted

10.1. It also didn't state in the manual that 87 could be used.

It's neat how these newer vehicles and the ECU's can adapt using different fuels.

 

When I owned my 2011 5.0 Mustang, Ford recommended running primium for full performance. However, if you ran 87; the HP numbers dropped to 402hp from 420hp. These GM engines are no different. ECU detects knock and retards the timing.

Jon A Senior Enthusiast

Jon A

Posted
Posted

 

I quoted my context directly from the GMC Denali owners manual along with a link to it. That is directly from GMC's site.

 

So your Denali is not a Sierra? You're driving a Yukon? Acadia? That you'd ignore what the Sierra manual says for the sake of winning an argument is enlightening.

 

 

Again, please prove that running 87 octane in this engine can and has harmed it.

 

Nice try, but GM themselves say in both manuals damage can occur. If you somehow think they are incorrect the burden is on you to provide some sort of evidence or technical reasoning explaining why. Your mindless argument could be applied to running 20K mile used oil. Or even no oil at all. What proof do you have that'll cause damage?

 

Just because nobody has been stupid enough to try it yet does not prove everything we know about the internal combustion engine needs to be re-proven from scratch just for you. Find one single engine builder or tuner who does not think running 87 octane in this engine can cause damage. To the contrary, most of them recommend running mid-grade or higher in the lower compression 5.3....

 

 

I will tell you that I ran 87 exclusively in my mercury marauder

 

Thanks for sharing, but that has nothing to do with this conversation.

 

 

10.1. It also didn't state in the manual that 87 could be used.

 

The L86 has a 11.5:1 compression ratio.

redwngr Senior Enthusiast

redwngr

Posted
Posted

http://sandyblogs.com/techlink/?p=2139

 

Article is from July 2013.

 

"The new 6.2L V8 (Fig. 8) will be available later this year. Vehicles equipped with the 6.2L V8 engine MUST use premium unleaded gasoline with a posted octane rating of 91 or higher. This engine is NOT E85 capable.

gaudette Enthusiast

gaudette

Posted
Posted

 

So your Denali is not a Sierra? You're driving a Yukon? Acadia? That you'd ignore what the Sierra manual says for the sake of winning an argument is enlightening.

 

 

Nice try, but GM themselves say in both manuals damage can occur. If you somehow think they are incorrect the burden is on you to provide some sort of evidence or technical reasoning explaining why. Your mindless argument could be applied to running 20K mile used oil. Or even no oil at all. What proof do you have that'll cause damage?

 

Just because nobody has been stupid enough to try it yet does not prove everything we know about the internal combustion engine needs to be re-proven from scratch just for you. Find one single engine builder or tuner who does not think running 87 octane in this engine can cause damage. To the contrary, most of them recommend running mid-grade or higher in the lower compression 5.3....

 

 

 

Thanks for sharing, but that has nothing to do with this conversation.

 

 

 

The L86 has a 11.5:1 compression ratio.

Sorry, but my reply has more to do with this conversation than most of the posts here. Compression ratio alone doesn't dictate whether premium fuel is required or not. Mazda's skyactiv engines have a compression ratio of 14:1 and run on regular fuel. Mazda is predicting a compression ratio of 18:1 in its future engines. My Triumph Street Triple is 12.65:1 and uses 87. The Yamaha WR250R requires 91 octane with 11.8:1 CR and I have experienced knocking with 87 but only when running hard on hot days. Direct injection allows for higher compression ratios in general, and the technology in new engines has allowed them to reach ratios where premium fuel was not just required but absolutely necessary.

 

As for why someone would buy the 6.2L and then not buy premium? I would assume it's due to availability rather than to save a few dollars. I would've considered the 6.2 but since I'm filling up mostly at commercial work sites I'd never see premium gas. If I did ever change my job I'd would've liked to have a 6.2 but that's a financial compromise I made.

 

Why this subject brings out the extremists is beyond me. The manual even says it's okay and who effing cares what someone does with their own truck anyway. If any damage would occur I bet it wouldn't be noticeable within the average time of first ownership.

Isriam Enthusiast

Isriam

Posted
Posted

 

So your Denali is not a Sierra? You're driving a Yukon? Acadia? That you'd ignore what the Sierra manual says for the sake of winning an argument is enlightening.

 

 

Nice try, but GM themselves say in both manuals damage can occur. If you somehow think they are incorrect the burden is on you to provide some sort of evidence or technical reasoning explaining why. Your mindless argument could be applied to running 20K mile used oil. Or even no oil at all. What proof do you have that'll cause damage?

 

 

2015-sierra-denali-owners-manual.pdf

 

I posted a link to the 2015 Sierra Denali owners manual. i'm not quite sure what you're smoking, but yes I own a SIERRA and the manual says you CAN run 87 in it.

 

You also CAN run your oil for 20,000 miles.

Jon A Senior Enthusiast

Jon A

Posted
Posted

 

I posted a link to the 2015 Sierra Denali owners manual. i'm not quite sure what you're smoking, but yes I own a SIERRA and the manual says you CAN run 87 in it.

 

 

And I posted a link to the 2015 Sierra manual. And quoted it. Twice. I really doubt you're too stupid to read and understand simple sentences. You know darn well the current Sierra manual says to only use 91 or higher octane. You're being dishonest.

 

Arguing with a dumb person gets old, arguing with a dishonest person gets really old. And while your outdated 2014 Sierra manual says you can use 87 octane, it also says that can cause damage. But you dishonestly pretend it doesn't and say I must be smoking something when I state it does. Nice.

 

And I didn't say anything about running your oil for 20K. You know what the word "Used" means, right? Of course you do.

Isriam Enthusiast

Isriam

Posted
Posted

Jon, I don't know what you're posting from, because you haven't linked the actual PDF. I did. It is the 2015 Sierra Denali owners manual. To say that I am being ignorant and posting an outdated manual is incorrect. Again, it is the 2015 Sierra Denali manual.

 

gmc.com/content/dam/GMC/global/master/nscwebsite/en/home/Owners/Manuals/01_Images/2015-sierra-denali-owners-manual.pdf

 

If the vehicle has the 6.2L V8 engine (VIN Code J), use premium unleaded gasoline meeting ASTM specification D4814 with a posted octane rating of 91 or higher. Regular unleaded gasoline rated at 87 octane or higher can be used, but acceleration and fuel economy will be reduced, and an audible knocking noise may be heard. If this occurs, use a gasoline rated at 91 octane or higher as soon as possible. Otherwise, the engine could be damaged

 

This is like talking to a brick wall.

thetruck454 Enthusiast

thetruck454

Posted
Posted

Because I like to stir the pot here is the regular sierra owners manual. Odd that they are different, I wasn't able to find a revision number or release date to see which one was newer.

 

http://www.gmc.com/content/dam/GMC/global/master/nscwebsite/en/home/Owners/Manuals/01_Images/2015-sierra-1500-owners-manual.pdf

 

On page 9-63 it states

 

"If the vehicle has the 6.2L V8 engine (VIN Code J), use premium unleaded gasoline meeting ASTM specification D4814 with a posted octane rating of 91 or higher. If the octane is less than 91, damage to the engine may occur and may void the vehicle warranty. If heavy knocking is heard when using gasoline rated at 91 octane or higher, the engine needs service."

Isriam Enthusiast

Isriam

Posted
Posted

Thanks for the link. I don't doubt that Jon found a manual that states 91 only, but my point is that the 2015 current sierra denali manual states 87 is ok.

 

I don't believe GM knows this or it would have been fixed.

Jon A Senior Enthusiast

Jon A

Posted
Posted

Jon, I don't know what you're posting from, because you haven't linked the actual PDF. I did.

 

Good grief. What a waste of time this is. Are you kidding me? What do you call this?

 

 

 

Should I quote it again for the forth time and put the part where they say using less than 91 can cause damage and may void your warranty in even bigger and bolder letters? Maybe you'll actually read it this time?

 

 

 

If the vehicle has the 6.2L V8 engine

(VIN Code J), use premium

unleaded gasoline meeting ASTM

specification D4814 with a posted

octane rating of 91 or higher. If the

octane is less than 91, damage to

the engine may occur and may void

the vehicle warranty. If heavy

knocking is heard when using

gasoline rated at 91 octane or

higher, the engine needs service.

 

Please tell me the 10 watt lightbulb finally flickered "on."

Isriam Enthusiast

Isriam

Posted
Posted

Again, I think everyone here gets the point except you. Continue on, I'm done proving my point. The manual in thousands and thousands of vehicles says 87 is OK.

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