This Just In... All 2008's must run PREMIUM!

[BigBlue]

You read it right... As I'm leaving service today, my tech pulls me aside and says, "We got a TSB last week, all 2008's need to run premium fuel."

:twak:

I call the Sales Manager, and give him my WTF speech. He confirms that the same bulletin came to him, and tells me "it sure ain't gonna HELP sales". No kidding buddy! What about those of us who just found out after the sale? What does this do to public opinion? What about resale?

Anyone else heard this?

[Fastest H-Town Realtor]

You read it right... <SNIP> What does this do to public opinion? What about resale? Anyone else heard this?

Huh? Public opinion? Resale? Your joking, right? :twak: Might as well throw the "cost of filling up" in there for good measure.


IMHO, anything rolling 400 HP should be fed a diet of hi-test ('member that word?:giggling: ). Unless it is a diesel.

[TXSUT]

What I want to know is the reason they are saying it's required.

[3Hummer]

i was almost positive that the H2 recommended premium to begin with?

[CO Hummer]

a diet of hi-test ('member that word?

Hahaha!! I remember it well. I haven't heard anyone but my Dad use that word in 20 years. He still uses it BTW. :D

[CO Hummer]

i was almost positive that the H2 recommended premium to begin with?

What? 87 Octane was always recommended from the beginning.

At high altitude, you use even lower octane.

[DennisAJC]

"it sure ain't gonna HELP sales". No kidding buddy! What about those of us who just found out after the sale? What does this do to public opinion? What about resale?

Anyone else heard this?


Affect sales??? What a stupid thing to say. The Hummer guzzles enough gas to begin with it won't make a dent in your pocket book. Unless you're on a tight budget. If so then you don't belong in a Hummer.:lame:

I've been using premium since 03 even though mine never required it. It just seems to run better. When I was filling up in the US with regular, it ran sluggish and my fuel pump whistled.:D

[mikejr]

OK just checked my manual for my 2008. Says that you should use 91 or better octane, but you can use 87 but your acceleration could be affected. It says if you notice a knocking then get the higher octane asap.

Anyone know WHY they issued this TSB?

[3Hummer]

even if you can run lower octane im sure hte car performs better on higher octane if thats whats recommended and it probably gets better mileage with the recomended to?!

[errett]

When I was filling up in the US with regular, it ran sluggish and my fuel pump whistled.:D

I envision this like a construction worker whistle from the truck to Dennis!:giggling:

E

[mikejr]

I ran regular in my 06 with no troubles.

Hopefully someone on here will be able to find out why they TSB was generated. I'll have to check with my dealer.

[NewHummerGuy]

I envision this like a construction worker whistle from the truck to Dennis!:giggling:

E

DAMN errett...........with 66 whole entire post them there is fighting words.

Good luck:twak: :giggling: :giggling: :giggling:

You, my friend errett, are referring to the MOTORBOATIN KING of the nothern United States:jump:

[errett]

DAMN errett...........with 66 whole entire post them there is fighting words.

Good luck:twak: :giggling: :giggling: :giggling:

You, my friend errett, are referring to the MOTORBOATIN KING of the nothern United States:jump:

Yeah, but I have been around long enough to know that you need to strike when you can to get Dennis. I may only have 66 posts, but I have read a ton.

He opened the door, I just helped him close it.

E

[blackhawk29]

can anyone get a copy of the TSB and post it ?

[mikejr]

can anyone get a copy of the TSB and post it ?

:iagree:

[tomp]

So the 6.2 is suppose to have more horsepower, so either:

-the increase in engine size bumped the compression as they used the same chambered heads
-increased timing
-or both of the above

I bet the first one is the answer and that is an Engineering mishap if they intended on the new models to use 87 octane. Every mechanical engineer knows when you increase bore size that you must also increase chamber size in the heads or compression goes up. Tis bump in compression also provides more performance at the cost of having to use higher octane fuel.

Let's see, they also added electric cooling fans which gave them about 15-18 more ponies. It's not hard to see where the extra power came from...

Hmmmm, I dont know about you guys - but as much as we have to put fuel in these things that extra $7.50 per tank sure will add up. This just made my decision not to buy a new one until the diesel comes out and to keep updating mine until then.

I bet that electric fan setup wouldn't be hard to retrofit on previous models

[imwoblin]

My 07 Escalade "recommends" the use of premium unleaded (owners manual). Since the H2 uses the same 6.2 as the Caddy, it would make sense to recommend premium unleaded.

[DRTYFN]

My 07 Escalade "recommends" the use of premium unleaded (owners manual). Since the H2 uses the same 6.2 as the Caddy, it would make sense to recommend premium unleaded.
But it's slightly detuned.
I guess I'll be waiting for the new H1.

[HUMMERcustoms.com/TAZ]

It will take a little time but, a company will come out with a hand held that will get more HP and most likely use some octane. Some tuning software will come out later that you could tune on laptop but, since caddy has been running the engine some tuning is already out there.

I will say try 87 as I have always tuned my rigs to get all HP I could get with recommended higher octane and then run 87. It has more bang or power due to lower combustion properties in formualtion.

It is up to all to make on judgement as I'm just offering my experience and it is quite abit. I have a 1999 Silverado 5.3L tuned for max HP etc. and has run 87 from almost day one and never had ping etc. It has 185,000 miles and uses not a half pint of oil in 3000 miles (Penn 10W30) and runs like a scaulded dog. It has electric fans, tuning, and all the other stuff tranny adjusted etc. I'm going to check compression on the engine and if OK putting a Turbo on it next spring or summer. Have the biggest tires on it that will fit stock rims that came on it and it is hard not to spin them on any take off even from just a stop light. I will of course go to other rims and real wide tires to bite and still take it out with tool box on the back and just have fun shocking people as it does now.

My H2 after we complete upgrades in elctronics I'm going to tune it some more boost up supercharger some more and see when i will need to get off 87 at 6lbs. of boost now. No pings anything but, it shocks people seeing mouths open like catching flies. It will almost take wheel out of hands at launch from torque steer.

We are going to strip rig down next Feb. 08 and media blast it with baking soda and get the body as smooth as we can to get it to really step up in the big leaque shows we hope. May change paint scheme some and if anyone would look up pics in the forum area I would be interested in some PM mail contact with sincere suggestions.

I had once before thought about letting the forum really help me decide on custom ideas so it would compete some under Our Forum name etc. I'm proud to be a part of this so suggestion and list of forum as sponsor if we can get good paint idea or other ideas also. So jump in and if you want to send me email powerpoint designs or mail anything contact me privately. It will be done in late Jan. or early Feb. 2008.

I'm going to look at sending in pics etc. to the spring SEMA 2008 GM only design and skill contest. They take only 20 rides total of any year car, truck, or SUV anything. We were picked for spring 2006 but, as we loaded on trailer to take it to Indy, IN we had a failure of some product not of our fault so had to call and pull out so they could call in an alternate. Director said shame they had thrown the H2 out of the yes pile many times because H2 has been done in SEMA shows allot but, it had some really unique custom work they had not seen any other Hummers do so they put us in and he felt we would get Best of Show. I wish he had not told me that as you can imagine how my heart sunk to my stomach. Well he said no problem and i figured they would hate us forever but, at end of phone call he said try again as soon as we could get ready. I told him we will most likely start over taking 2 years for allot of suttle changes, he said still no problem let them know. He said it takes even more time on some cars.

So if Forum wants to involve itself any it will be taken seriously if given seriously. Ideas given and used will be added to list of sponsors on our show board with a few other individuals who gave ideas before from this forum.

Sorry to get into this as i know many do not care for bling but, believe me it wins allot of good will when we get to tell people about it and regular street Hummers always come up and we get to put out truths to counter all the lies. It just happened but, glad i did.

Try 87 at own risk. I did and loved it.

TAZ

[H2R]

Fuel is still available at .87 cents a gallon like in QATAR and to top it off its 97 octane! I wonder where its cheapest?:dancingbanana: :excited: :fdance:

[Agriv8r]

2000 miles in burning 87, no problems at all...no pings, no issues....

[devilsfan]

I agree. Was the engine in the 08 drastically changed from previous years? I've been running 87 in my 03 since day 1 with no issues.

Big question is - if you run 87 in an 08 and DO have issues, will your warranty still cover it?

Stacy

[DennisAJC]

I envision this like a construction worker whistle from the truck to Dennis!:giggling:

E

I get that alot too but this whistle is definitely from my H2.:D

[DennisAJC]

You, my friend errett, are referring to the MOTORBOATIN KING of the nothern United States:jump:

Starting to sound like another H2 club....


TEAM MOTORBOAT - Northern US Hummer Chapter

"We're Sons Of Bitches"

:jump:

[NewHummerGuy]

TEAM MOTORBOAT - Northern US Hummer Chapter



"We're Sons Of Bitches"



:jump:
[/quote]


Holy $hit. Ok no one steal this. Its mine all mine:jump:

[DennisAJC]

Holy $hit. Ok no one steal this. Its mine all mine:jump:


HAHAHA!!!! It's a better name than that ghey sheep something.:giggling::jump:

[Sewie]

HAHAHA!!!! It's a better name than that ghey sheep something.:giggling::jump:

HEY!!! Don't piss off the sheep! :mad: ;) :fdance:

http://www.blacksheep-themovie.com/

[mikejr]

2000 miles in burning 87, no problems at all...no pings, no issues....

a tad over 1500 on my burning up the 87 octane and no pings or other issues. Maybe i'll dump in a load of hi-test and see how it runs....

[DennisAJC]

HEY!!! Don't piss off the sheep! :mad: ;) :fdance:

http://www.blacksheep-themovie.com/

JEEBUS! You know I'm teasing!:D

[Takecover]

I agree. Was the engine in the 08 drastically changed from previous years? I've been running 87 in my 03 since day 1 with no issues.

Big question is - if you run 87 in an 08 and DO have issues, will your warranty still cover it?

Stacy

Yes, in the event you have an internal engine problem, the tech, or field rep would check the ECM history of knock detectors, and run a fuel quality test. I would make sure you had premium fuel in the tank in the event of a failure. I have seen warranty work declined for poor fuel quality!

Jimmy

[H2Finally]

HEY!!! Don't piss off the sheep! :mad: ;) :fdance:

http://www.blacksheep-themovie.com/The one scene that cracks me up was when that guy in boxers was smokin an after-sex cigarrette, and an ewe walked in from the bathroom door, and he said to the other guy starring at them dumb-foundedly, "you wouldn't understand..." :jump:

[dochummer]

My cousin's been running premium in his 2003 H2 since he got it. He says it pings on him when he runs regular...

[Hummer Guy]

I may have to call BS on the 'bulletin'....There's no recent bulletins of that nature and no bulletin that mentions octane in the last 2 years in H2 or H3...Not sure what the owners manual says, but I haven't seen anything from GM about it...

[johndjmix1]

Weird. I run 87 in my 2006 AND I have the supercharger. Still no pings.

--John

[Hummer Guy]

Alright, I looked a little further and found a "facts and myths" bulletin on fuel/additives for ALL 2008 and prior GM cars and trucks:

This is straight from the bulletin:
? Use the Recommended Grade (Octane) Fuel
Purchasing higher than required octane fuel is a waste of money. Using higher octane fuels in a vehicle that only required regular unleaded fuel will neither increase performance nor improve gas mileage. In all cases refer to your owners manual and ONLY use the octane rated fuel recommended for your vehicle.

Important: In high performance GM vehicles that DO require Premium (91 octane or higher) fuel, you MUST use fuels of at least this octane. Use of lower octane fuel may result in reduced performance, knocking, and/or permanent engine damage not covered under the terms of the New Vehicle Warranty.

This is straight from the 08 manual:

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 your vehicle's acceleration could be slightly reduced, and you might notice a slight audible knocking noise, commonly referred to as spark knock. If the octane is less than 87, you might notice a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you could damage the engine. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service.

_________________________________

So, I read the owners manual as 87 octane is acceptable for use. I've driven a ton of 08s on regular octane and never heard any knocking. The bulletin talks about vehicles that "Require premium" and the manual says "You can also use regular unleaded gasoline rated at 87 octane."

The high performance cars I've seen that run on higher octane say "Always use premium fuel, below 91 octane may damage engine components bla bla bla"

87 Octane is fine in 2008 H2s and H3s - has anyone here heard knocking?

[blackhawk29]

after reading the instructions (owners manuel) it seems like gm has learned that we build or buy something first then read instructions later....checked the manual and sure as the sun comes up it says to run 91+ octane (premium fuel) did they "forget" to place this below the fuel gauge, or on the filler cap? I have owned several cars that required premium and all said it on the cluster. I drive a lot of miles and this will add up fast. Maybe this expains my consistant rough idle. :crying:

[mikejr]

Alright, I looked a little further and found a "facts and myths" bulletin on fuel/additives for ALL 2008 and prior GM cars and trucks:

This is straight from the bulletin:
? Use the Recommended Grade (Octane) Fuel
Purchasing higher than required octane fuel is a waste of money. Using higher octane fuels in a vehicle that only required regular unleaded fuel will neither increase performance nor improve gas mileage. In all cases refer to your owners manual and ONLY use the octane rated fuel recommended for your vehicle.

Important: In high performance GM vehicles that DO require Premium (91 octane or higher) fuel, you MUST use fuels of at least this octane. Use of lower octane fuel may result in reduced performance, knocking, and/or permanent engine damage not covered under the terms of the New Vehicle Warranty.

This is straight from the 08 manual:

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 your vehicle's acceleration could be slightly reduced, and you might notice a slight audible knocking noise, commonly referred to as spark knock. If the octane is less than 87, you might notice a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you could damage the engine. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service.

_________________________________

So, I read the owners manual as 87 octane is acceptable for use. I've driven a ton of 08s on regular octane and never heard any knocking. The bulletin talks about vehicles that "Require premium" and the manual says "You can also use regular unleaded gasoline rated at 87 octane."

The high performance cars I've seen that run on higher octane say "Always use premium fuel, below 91 octane may damage engine components bla bla bla"

87 Octane is fine in 2008 H2s and H3s - has anyone here heard knocking?

No i've had no knocks, but the engine does idle a bit rough. But I just figured it was how the engine was supposed to idle. Almost like it has a hypo cam in it or something.

[Alan06SUT]

I bet mid grade would work fine.

[Agriv8r]

after reading the instructions (owners manuel) it seems like gm has learned that we build or buy something first then read instructions later....


:giggling:

[Hummer Guy]

No i've had no knocks, but the engine does idle a bit rough. But I just figured it was how the engine was supposed to idle. Almost like it has a hypo cam in it or something.

I don't think higher octane would smooth the idle, but I agree that 2008 models idle a little rougher. The exhaust, to me, sounds a lot better too (more aggressive), and that's just one of the 'downsides' to having the bigger, nearly 400 HP engine in the '08 :D

[jmsspratlin]

:raar:

[Tex_h2]

For 11 years I ran 93 octane in my truck, and now with a jet chip I still run 93 octane..(actaully have to) Some say it doesn't matter, some say it does....I think it does matter.....

[Agriv8r]

For 11 years I ran 93 octane in my truck, and now with a jet chip I still run 93 octane..(actaully have to) Some say it doesn't matter, some say it does....I think it does matter.....

if you dont change it how do you know....

[mikejr]

I don't think higher octane would smooth the idle, but I agree that 2008 models idle a little rougher. The exhaust, to me, sounds a lot better too (more aggressive), and that's just one of the 'downsides' to having the bigger, nearly 400 HP engine in the '08 :D

I remember when they bumped up the HP in the avalanch from 2003 to 2004 it idled rougher too.

I agree with you, that exhaust sounds AWESOME....thats probably why I am only getting 10.7 MPG, I keep putting my foot into it to hear that rumble. It is sweet sounding.

Mike

[BigBlue]

I remember when they bumped up the HP in the avalanch from 2003 to 2004 it idled rougher too.

I agree with you, that exhaust sounds AWESOME....thats probably why I am only getting 10.7 MPG, I keep putting my foot into it to hear that rumble. It is sweet sounding.

Mike

Yeah, that new rumble is definately worth the extra .20 a gallon.

[frenzy1]

:fdance: I'M DRUNK :raar: :raar: :raar: :raar: :lame: :notallthere: :grouphug: :orly:

[Agriv8r]

:orly:

[H2 007]

Have the same slight rough idle at times as others have mentioned. Have been using Shell 87 since day one. Just filled up today and got 13.6 MPG, city driving, with 1050 miles on it.

On the highway, if I set the cruise to 65MPH, I can get a solid 16 - 17 MPG. Driving around rural roads at 40-45MPH and I have seen 18+ MPG.

Of course this is all with very conservative driving.

No knocks, pings or anything else for that matter.

Overall, I think this new engine / trans / gearing is great.

[HUMMERcustoms.com/TAZ]

Bumping HP is just adding fuel/air then adjusting timing. If you are running what factory calls for then take it to dealer and have it checked something is wrong. It could even be the knock sensor. You may need a spark plug colder or hotter. There are so many variables to a knock it takes someone with software etc. to check it out. You could play with a handheld, experiment taking notes save allot of money and figure it out.

Tuning is note hard just requires some study up front on how the new stuff works. I use to just ear tune back in the muscle car days. I miss it. Run Accel distributor stuff etc. Figure fuel/air ratio on a printed table based on carb, heads, cam, and just figure your way. Once it was all done the final timing was done by ear at about 2000/2500 rpm by ear no timing light. I could put my 68 Mustang 289HP 3/4 race cam, roller rocker/lifters, and tunnel ram then time it perfectly on the money. Next it was pink slip time.

TAZ

[blackhawk29]

Have the same slight rough idle at times as others have mentioned. Have been using Shell 87 since day one. Just filled up today and got 13.6 MPG, city driving, with 1050 miles on it.

On the highway, if I set the cruise to 65MPH, I can get a solid 16 - 17 MPG. Driving around rural roads at 40-45MPH and I have seen 18+ MPG.

Of course this is all with very conservative driving.

No knocks, pings or anything else for that matter.

Overall, I think this new engine / trans / gearing is great.

for what it matters my 08' f-450 twin turbo idles smoother than my 08 H2. Sounds like most 08's have a rough idle. at a stop light the other day, the engine idled up by itself kinda lurched forward, if i did not have the brakes firmly on it would have ended up in the back of someones car. i think gm has something messed up with the ECM fuel mapping and they need to issue a reflash update. My idle is so rough that it almost feels like its going to stall out, i can watch a bottle of water jump all over the place in my cupholder. I can also feel it through the brake pedal. I'm all for the exhaust note and hot cam, but can't we have that with a vehicle that idles properly?

[WikidPete]

I've got almost 7,000 miles and still running great... :jump:
I do agree the engine has a bit of a rough idle.

[Tex_h2]

if you dont change it how do you know....

I have used reg, every now and then and noticed a lag or decrease in power

[Tex_h2]

for what it matters my 08' f-450 twin turbo idles smoother than my 08 H2. Sounds like most 08's have a rough idle. at a stop light the other day, the engine idled up by itself kinda lurched forward, if i did not have the brakes firmly on it would have ended up in the back of someones car. i think gm has something messed up with the ECM fuel mapping and they need to issue a reflash update. My idle is so rough that it almost feels like its going to stall out, i can watch a bottle of water jump all over the place in my cupholder. I can also feel it through the brake pedal. I'm all for the exhaust note and hot cam, but can't we have that with a vehicle that idles properly?

That sucks......I have to say my 04 pur's like a kitten

[j e f f x o 6 x]

im close to 10,000 miles on my 08 H2 and still running strong with 87 octane :excited:

[mikejr]

I've got about 4K on my 08 and she's running like a top. Yes, the idle is rougher than what it was in my 06. I've been burning regular in it since day 1. Maybe will try a load of hi test in it to see what happens.

I recall when they bumped the ponies up in the avalanche from one year to the next, the newer one had the same rough idle situation....went from an 03 to an 04.

[CovertH2]

The Diablo Predator programmer has a program for 87 octane, just ran it into my '08 two days ago, runs fine. Prior to that no issues ever running on unleaded. FYI.

[Little General]

I got 3000+ miles on my 08 and have run 93 since new. Found out the other day that the dealer puts 87 in for the free tank with purchase because of the cost. On top of that , this is the first new car I have ever bought that did not include the first oil change free. I read it is the same +/- engine as the corvette and all corvettes come with Mobil 1 from the factory, H2's come with dino. Since I had to do my first oil change at my cost, I put Mobil 1 in mine. I will report if mpg's change.