Pre-detonation

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ZR2 community,

Good day to all...

Bought a 2023 ZR2 last May and love the truck...however, got a question for all the ZR2 owners out there...What octane fuel do you run?

I have been using regular 87 octane since I drove it off the lot...about 3 months ago, it started to ping...rather aggressively...I thought it might be the software push they did around that time. I searched this forum and noted that some people are experiencing this, but not all...I have not tried 91 octane yet but an going to...

To those folks out there using 87 octane, do you get pre-detonation? Is anyone using 91 octane and getting pre-detonation?

Thanks...
 
ZR2 community,

Good day to all...

Bought a 2023 ZR2 last May and love the truck...however, got a question for all the ZR2 owners out there...What octane fuel do you run?

I have been using regular 87 octane since I drove it off the lot...about 3 months ago, it started to ping...rather aggressively...I thought it might be the software push they did around that time. I searched this forum and noted that some people are experiencing this, but not all...I have not tried 91 octane yet but an going to...

To those folks out there using 87 octane, do you get pre-detonation? Is anyone using 91 octane and getting pre-detonation?

Thanks...
It is recommended you use, at a minimum, 91 octane in the 6.2. I use 93 octane and no issues.
 
I also use 91 (93 if avail) and never experienced the pinging. Definitely stop using 87 and only use 89 if 91 or 93 are not avail. You bought an expensive truck to operate.
 
You should be running 91 min. The compression ratio is 11.5 on a 6.2. That's really high to be running 87 regardless of retarded timing. Really shouldn't go off randoms on the internet saying they do something and nothing bad has happened, so it's fine, lol.

If GM could make those numbers on 87 and meet emissions, they would. It would help them sell more 6.2s. Telling people they need to run premium turns a lot of people away. They don't call for 91 just for the heck of it.
 
ZR2 community,

Good day to all...

Bought a 2023 ZR2 last May and love the truck...however, got a question for all the ZR2 owners out there...What octane fuel do you run?

I have been using regular 87 octane since I drove it off the lot...about 3 months ago, it started to ping...rather aggressively...I thought it might be the software push they did around that time. I searched this forum and noted that some people are experiencing this, but not all...I have not tried 91 octane yet but an going to...

To those folks out there using 87 octane, do you get pre-detonation? Is anyone using 91 octane and getting pre-detonation?

Thanks...
93 in my area...nothing less will do.
 
I usually run 91, but I've run plenty of 87 and never had any issue. If anything mileage may have been down a little.

I've posted the statement right out of the manual that says 87 is fine. But if it's not working for you and you don't have access to premium, add some octane booster when you fuel up.

I'd take it to the dealer anyway for a look-see.
 
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I usually run 91, but I've run plenty of 87 and never had any issue. If anything mileage may have been down a little.

I've posted the statement right out of the manual that says 87 is fine. But if it's not working for you and you don't have access to premium, add some octane booster when you fuel up.

I'd take it to the dealer anyway for a look-see.
Thanks AXE...I read they (chevy) "recommends 91 octane" but just like you noted, it also states that 87 if fine...while I don't mind switching to 91 octane, what was interesting is the truck ran fine for about the first 3000 miles on 87 and the last 1000 is when it started to ping...I am going to fill her up with 91 on the next fill and see if that takes care of the knock...if so, then we have the solution. If not, will definitely take it in just to be sure...
 
Maybe there's been some fuel quality issues with supplier.

I've only used it when on road trips. I figured at steady throttle and burning a tank every 4+ hours it wouldn't matter much. I did a trip with my wife's 6.2L Tahoe in December and got the best mileage I've seen at 19 mpg on a road with lots of elevation changes and trying to run 70-80 mph. That was loaded with 5 people and gear and the Tahoe weighs more. Ran like a champ for 300 miles.
 
ZR2 community,

Good day to all...

Bought a 2023 ZR2 last May and love the truck...however, got a question for all the ZR2 owners out there...What octane fuel do you run?

I have been using regular 87 octane since I drove it off the lot...about 3 months ago, it started to ping...rather aggressively...I thought it might be the software push they did around that time. I searched this forum and noted that some people are experiencing this, but not all...I have not tried 91 octane yet but an going to...

To those folks out there using 87 octane, do you get pre-detonation? Is anyone using 91 octane and getting pre-detonation?

Thanks...
I only use 91 octane. no pinging. The fuel specification calls for 91 octane.
 
I use 93 octane in both my ZR2 and the wife’s vette. High compression / high performance motors need a higher octane to prevent detonation.
 
If you can afford the truck...you can afford 91-93 octane ;)
Not really the point, there are people that live in areas what fuel can be harder to come by. There's no reason you can't run 87, it says so in the manual. If it won't work on 87, you got a GM problem, not a bank account problem.
 
Not really the point, there are people that live in areas what fuel can be harder to come by. There's no reason you can't run 87, it says so in the manual. If it won't work on 87, you got a GM problem, not a bank account problem.
Harder to come by? Really??? This s the United States :ROFLMAO: No fuel lines or supply chain issues here related to gasoline. Everywhere you go you can find at least 89-91. GM recommends 91 at a minimum unless you can't find it, then 87 is ok but not recommended long term.
 
Harder to come by? Really??? This s the United States :ROFLMAO: No fuel lines or supply chain issues here related to gasoline. Everywhere you go you can find at least 89-91. GM recommends 91 at a minimum unless you can't find it, then 87 is ok but not recommended long term.
On a road trip thru OK last month I had to fill up with 89 because there was nothing higher at the pump and this was a Loves right off I-35.
 
Harder to come by? Really??? This s the United States :ROFLMAO: No fuel lines or supply chain issues here related to gasoline. Everywhere you go you can find at least 89-91. GM recommends 91 at a minimum unless you can't find it, then 87 is ok but not recommended long term.

Arizona, Wyoming, and Nevada have entered the chat.

You're not correct with your assessment of fuel availability in rural America. There are locations out west where you can run 100 miles between towns with services. There are places where you can still find single pumps at a place that serves as the grocery store, resturant, post office, and gas station.

There are places in western US, especially on Indian reservations where people still have no electricity, running water, or sewer. I live within 200 miles of several of them.

I have done projects in 17 states in the western US and can assure you services most people take for granted can be a tank of 87 away and you might drive something with the bumpers barely hanging on or you might drive a late model.

I've had trouble getting both gas and diesel and coasted into town hoping there was a working pump.
 
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Arizona, Wyoming, and Nevada have entered the chat.

You're not correct with your assessment of fuel availability in rural America. There are locations out west where you can run 100 miles between towns with services. There are places where you can still find single pumps at a place that serves as the grocery store, resturant, post office, and gas station.

There are places in western US, especially on Indian reservations where people still have no electricity, running water, or sewer. I live within 200 miles of several of them.

I have done projects in 17 states in the western US and can assure you services most people take for granted can be a tank of 87 away and you might drive something with the bumpers barely hanging on or you might drive a late model.

I've had trouble getting both gas and diesel and coasted into town hoping there was a working pump.
I am not referring to "rural" America. I am referring to mainstream American where most of the population lives. If you live in Timbuktu where they get a gas delivery once every week or two, then that's to be expected. I doubt anyone would have any issues if you live near any major city or suburb as most folks do. Anywhere that has a single pump that serves as a restaurant, grocery store, post office, gas station, cannabis sales, erectile dysfunction meds, etc. should be expected to have shortages based on delivery schedules.
 
To the OP---if you have knocking you have (A) bad fuel or (B) a problem with the sensors and possibly other things with the fuel system. Pre detonation or "pinging" as some call it went away many years ago with modern ignition systems on vehicles which adjust timing continuously.

By running the higher-octane fuel which does contain less energy btw will give you better gas mileage and more power as it allows the fuel to be compressed more before ignition. When on the light duty vehicles do the testing for the EPA sticker, they use higher octane fuel because it will help the fleet average and to possibly avoid the GGT.

Do not worry if you are running 93 or 90 as this number will change depending on where in the country you live, and it is driven by altitude. For example, in DFW we have 93 octane, go 300 miles to the west it goes to 91 and in the higher elevations e.g. mountains will go to 90.

Lot of information about including SAE White Papers about Octane and fuel, this is an excellent summary.


This is a good summary of what may be going on and will give you more insight. Lot of well-meaning folks here who are not really familiar with this subject but will after reading this.

 
Here's the fuel info from the manual.

I think you may have gotten some bad fuel that didn't meet spec or you might be having another mechanical issue.

I've run at least 300 gallons through two 6.2L motors in past year and didn't experience any perceptible performance or driveability issues.
 

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I am not referring to "rural" America. I am referring to mainstream American where most of the population lives. If you live in Timbuktu where they get a gas delivery once every week or two, then that's to be expected. I doubt anyone would have any issues if you live near any major city or suburb as most folks do. Anywhere that has a single pump that serves as a restaurant, grocery store, post office, gas station, cannabis sales, erectile dysfunction meds, etc. should be expected to have shortages based on delivery schedules.
Mainstream America........WTF is that? Does that mean Florida where you live in a state with 50% of the land mass and 22 million of your closest friends?

I thought it was a straight line from Amarillo, Texas to Fortuna, North Dakota on US 85 where you might find a couple towns with 10,000 people in 1200 miles.
 

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