Running reg or medium grade fuel with the 6.2?

[flyingz06]

anyone running reg or medium grade fuel with the 6.2? if so any trouble?

 

 

 

 

 

thank you.

[K2jer]

I got my truck with half a tank. When I got on it or heavy load it was pinging. Filled up with 91 and seems to have gone away. Only 325km's so far but I'm going to stick with 91 or higher from now on.

[lba0213]

I run 91 in mine and have no issues. 2k+ miles so far. Getting around 16-17 mpg

[fondupot]

it'll run fine. Just wont have very good performance or mileage. Use 91+

[Horacio]

Mine came with a full tank of gas from the dealer. I could tell after 5 minutes of driving that it wasn't 91.

Pinged like crazy.

After using no Vasaline, I was hoping the dealer would at least give me 91.

[Rewillia]

I tend to always buy the highest octane / lowest ethanol blend and never below the Manf's recommended octane.

[TJay74]

Maybe in really cold weather you could do this, but once the temps get over 40° you are going to want 91/93 octane. As said lots of scans of the 5.3 and the 6.2 motor have shown that even on 91 octane under some conditions there is some knock retard (KR) being seen and logged by the ECM.

[thetruck454]

As said many times before, you paid how much more to get the 6.2, why risk detonation with anything lower than 91 octane?

[flyingz06]

either way. at only $7 a fill up difference no biggie. just wondering

[redwngr]

As said many times before, you paid how much more to get the 6.2, why risk detonation with anything lower than 91 octane?

+1

Especially when the manufacturer says that's what should be used for the 6.2.

[Isriam]

dont listen to these guys. i ran 87 for months in mine with no issues, and awesome MPG.

 

the engine will retard the timing to compensate for pinging/knock. once its done, you will notice that the truck doesn't take off as well and generally is slower, but your mpg will be great with 14-16 city and 20-23 highway.

 

that being said, i went to 93 + custom tune because the truck drives so much better and i can actually milk a little more mpg out of it by using less throttle now. Owners manual says you SHOULD run 91 or higher, but it does not say you must, and the computer will compensate if you don't.

 

I also don't think anyone could ever prove you ran 87 octane either, they might like to try and say oh your engine is dirty or some such nonsense, but it wouldn't hold up in court. look how dirty these valves are with 93 octane and no catch can.

 

do it if you want, it won't affect the lifetime of the engine. i would install a catch can and run 91+ though if it were me, just because the owners manual suggests. If you're trading it in 3-5 years, its all your choice.

[TJay74]

dont listen to these guys. i ran 87 for months in mine with no issues, and awesome MPG.

 

the engine will retard the timing to compensate for pinging/knock. once its done, you will notice that the truck doesn't take off as well and generally is slower, but your mpg will be great with 14-16 city and 20-23 highway.

 

that being said, i went to 93 + custom tune because the truck drives so much better and i can actually milk a little more mpg out of it by using less throttle now. Owners manual says you SHOULD run 91 or higher, but it does not say you must, and the computer will compensate if you don't.

 

I also don't think anyone could ever prove you ran 87 octane either, they might like to try and say oh your engine is dirty or some such nonsense, but it wouldn't hold up in court. look how dirty these valves are with 93 octane and no catch can.

 

do it if you want, it won't affect the lifetime of the engine. i would install a catch can and run 91+ though if it were me, just because the owners manual suggests. If you're trading it in 3-5 years, its all your choice.

 

 

Please don't listen to this guy, I mean unless he is going to write you a blank check in case you destroy your motor.

 

While the ECM has several timing maps it can use and it will try based off of the detonation information (knock retard / KR) to retard the timing and drop into the low octane table it is possible that even with the max timing retard that if you have enough detonation you could damage the piston or valves in the engine if you continually allow detonation to happen to the engine.

 

If you are ok with that go ahead, I mean the LT1 motor in these trucks is prob only $10k and is chump change for most people I guess.

 

The only way I would run 87 in my truck was if I absolutely had to, even then I would baby it as much as possible. The warmer it is outside the easier you need to take it. The hotter intake air temps will cause detonation to be more pronounced versus when it is cold outside. Run 87 in an emergency in the 6.2 and you will be fine, run 87 all of the time and eventually I could see some issues down the road. Will those issues happen while you are under the powertrain warranty, who knows. I wouldn't want to take that gamble.

 

The idea behind octane is to run the lowest octane needed to keep detonation from happening, and I don't mean keeping detonation at bay by retarding the timing (via the computer). You will make the most horsepower and get the best fuel economy by running the lowest octane that prevents detonation. So far just about anyone that has logged data on the 6.2 has found under hot operating temps they will show some detonation, Justin from Blackbear has even noticed the 5.3 motors detonating on 87/89 and suggests to run 91 in them.

 

Your truck so do what you want, I fill up at no less than a half tank each week unless I am on a road trip. The difference is maybe $.50 per gallon or $7-10 per tank. Cheap insurance in my mind.....

[Isriam]

 

 

Please don't listen to this guy, I mean unless he is going to write you a blank check in case you destroy your motor.

 

While the ECM has several timing maps it can use and it will try based off of the detonation information (knock retard / KR) to retard the timing and drop into the low octane table it is possible that even with the max timing retard that if you have enough detonation you could damage the piston or valves in the engine if you continually allow detonation to happen to the engine.

 

If you are ok with that go ahead, I mean the LT1 motor in these trucks is prob only $10k and is chump change for most people I guess.

 

The only way I would run 87 in my truck was if I absolutely had to, even then I would baby it as much as possible. The warmer it is outside the easier you need to take it. The hotter intake air temps will cause detonation to be more pronounced versus when it is cold outside. Run 87 in an emergency in the 6.2 and you will be fine, run 87 all of the time and eventually I could see some issues down the road. Will those issues happen while you are under the powertrain warranty, who knows. I wouldn't want to take that gamble.

 

The idea behind octane is to run the lowest octane needed to keep detonation from happening, and I don't mean keeping detonation at bay by retarding the timing (via the computer). You will make the most horsepower and get the best fuel economy by running the lowest octane that prevents detonation. So far just about anyone that has logged data on the 6.2 has found under hot operating temps they will show some detonation, Justin from Blackbear has even noticed the 5.3 motors detonating on 87/89 and suggests to run 91 in them.

 

Your truck so do what you want, I fill up at no less than a half tank each week unless I am on a road trip. The difference is maybe $.50 per gallon or $7-10 per tank. Cheap insurance in my mind.....

 

Again like I said, it cannot be proven you didn't use 91, and the computer offsets timing for almost all of these engines anyway. I promise the 5.3 on 87 will have KR as well. The compression ratio is just too high for it to not happen. Look at the dirty valves in the engine forum, after 5k miles. That will be the failure on these engines long before KR, because the engine can fix knock, it cannot fix DI oil deposits.

 

Most people on this forum seem to trade their vehicle every 3-5 years anyway, so no, 87 octane in that time frame is not going to matter. Long term? Yes, run 93+ and use a catch can.

[KARNUT]

This is just some of the reasons I bought the 5.3. I can get E85 in my area, Im currently paying 1.49 a gallon in my area and have 380 HP. Due your research if you don't need the 6.2 its a waste all the ways you look at it. I cant imagine paying for the 6.2 and putting 87gas in it, you would be under the power level of the 5.3 whats the point? If I was going to pull with the 5.3 I would just gear it and still be money ahead, and have all the fuel options. Buy not offering E85 in the 6.2 but in the 5.3 that's a big sucker punch by GM.

[Isriam]

i dont think he asked if you should, he asked if there was any trouble running 87/89 octane. No there isn't, but there COULD be, and you SHOULDN'T. That sums up this thread. If you're selling your truck in 3 years, put whatever you want in it.