I just came back from a 500 mile round trip drive through Pennsylvania and I got 16.3 MPG on the highway and about 14 MPG over all. Not only am I getting good gas mileage but I think I feel a difference in my 2004 vs. a friend's 2003 with respect to torque and climbing hills. I heard that GM tweaked the engine in 2004 and think this is the case particularly given my experience on the gas mileage.

I just came back from a 500 mile round trip drive through Pennsylvania and I got 16.3 MPG on the highway and about 14 MPG over all. Not only am I getting good gas mileage but I think I feel a difference in my 2004 vs. a friend's 2003 with respect to torque and climbing hills. I heard that GM tweaked the engine in 2004 and think this is the case particularly given my experience on the gas mileage.

Do you feel a good difference or bad?


.

"Follow the white rabbit..." Morpheus 1999

Good difference. It seems like there is more torque up hills and better acceleration from standing position. I don't know if this is just in my mind.

I read on the internet ( so it must be true), that they made some adjutments to the computer programing..This may account for the powerband shifts you are noticing...

I am waiting on my Hypertech III, whichis suppose to be in route.. With any luck it will give me a small boost.. I've gone the supercharger route on another GM product. Don't bellieve I will do it again..

Mike

Mike,

Where did you buy your Hypertech? I am interested in buying one to change the downshifting of the transmission (much too quick to downshift going up moderate grades with the cruise engaged).

Beware that there are 2 different models with the same part number. I received this email from Hypertech this morning:

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>We have just released the programmer for the H2 recently and it is readily available. Part# 30019 is the correct unit, it must be a new 30019 before it will recognize the H2. An old 30019 off a shelf at one of our warehouses will not work. Thanks

Jim
<HR></BLOCKQUOTE>


Klaus

"God made some men big and some men small, but Sam Colt made them all equal."

Sounds great Zazing! That would be good news.

I could just hear the engineers meeting now:
"Okay, I have an idea. Whatever the computer calculates for MPG, lets add +3 to the display!"



- Dan

-------------------------------------------------
SUT on order 12/02. 10 months down, 8 to go!
-------------------------------------------------

THANKS for the positive reply, Zazing.


.

"Follow the white rabbit..." Morpheus 1999

Could be an air intake tuning, maybe better valve timing and springs. Hmmm. Glad you're enjoying it, Z!

Corvette= "The ability to pass with class"

I called mfg. week ago to day. they state dproduct was in stock retail $439.95.. I went on line and I think the name of the company was access ??/.. Hell I can't remember.. will have to check charge card record.. ( Still isn't here ,however must come from Cal..).. THe cost with shipping was just under $315.00...

I've used one of these on the last 10 GM Trucks/SUV's...

Mike

OK I found it. www.accessconnect.com hope this works.. My short term memory seems to be fading.


Mike

What is this about the 2004 being tuned (or improved programming) for better mpg and torque??? Is this true?? Let's hear some authoritative input.

Jim
Red H2

I have an 04 with 2700 miles on it. I do about 50/50 city/highway. Right now the computer says I am getting 11.4 Just an update for comparison.

Craig

Would it be too much to ask GM to give the update to dealers so our "old" engines could be tweaked?

HA!!! Dan is probably right on...if not, he is at least "funny"!

Man, I didn't see 11.4 until I hit the 5,000 mile mark.

Ric

OMAHOG/IHOG
Hum2@cox.net

More info from Hypertech:

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Klaus

The units with the revision# 05-18-14-20 is the correct unit for the H2. The revision # is located on the back of the unit on the parts # label.
Hypertech by EPA law can not make adjustments to the shift points at part throttle. It will not help with the down shifting problem .

Jim

-----Original Message-----
From: Klaus
Sent: Tuesday, October 21, 2003 7:41 AM
To: techsupport
Subject: Re: ChipRequest
Importance: High


Thank you very much for your reply. Can you give me further details? I am
primarily interested in stopping the transmission from dropping down a gear
too quickly when the cruise control is on. Will the HPPIII help?

Also, since the part numbers are the same, how can I tell if the programmer
is one of the "new" units just by looking at it? I'd hate to buy one, bring
it home, connect it up, only to find it is the wrong unit. Many times,
electrical parts cannot be returned once used.


Thank you,

Klaus <HR></BLOCKQUOTE>

Klaus

"God made some men big and some men small, but Sam Colt made them all equal."

I am getting pretty decent gas milage of 12.4 with my 2003. That is combination of city and highway. The only time I have noticed you can average 14 to 16 mpg is when you are traveling on a level road and going about 40 to 50 mph. I do however have the H2 reprogramed with a Predator, JBA shorties, Corsa Sport, and Nology wires.

2003 Pewter H2

I was getting about 12.2 avg in Dallas area. Now temporarily located in St. Louis area I am getting about 11.6 avg. (more hills). None of this could really be considered "highway" driving. I am at 12000+ miles and never noticed a measurable improvement after 5000 miles as some have reported.

Jim
Red H2

My 2003 has been solid at 13.0 mpg, now at 13,500 miles (no mods). Combination of city/hwy and when at hwy I run 70-75mph. I too only see 14-15 mpg when running at about 50 mph on level road. I consider 13.0 mpg to be just fine.

JJ

Zazing & other 2004 owners:

Let's hear how you are doing with MPG!

I have a neighbor with a new 2004 - I'll ask as well.

Lucky SOBs I have never seen 11 mpg. I have been getting about 10 before and after headers and Corsa. By the way I have a 2003.

My 2003 still gets 10.4.. Got a heavy foot. didn't care what the mileage was before I bought.. I do not care now after 8K miles.. still get 10.4mpg.. WOuldn't even know this if the H2 didn't keep track.. I just go to station when its thirsty and move on.. Like my daughter says its a "coke machine with wheels, not a sports car"..
ALl I know is its cool and mileage is not a issue in INdy with gas back down to 140 a gallon.. Besides I am use to feeding my older custom suburban that gets under 9 mpg ( I think). and it holds 45 gallons and I have to use prem + booster to feed the supercharger. So the H2 mileage ain't no big thing.

Mike

So I did more experimenting over this weekend. Best I got was 17.6 MPG with cruise control at 55 MPH. No joke. Overall I'm still getting 14 MPG. Mostly suburban driving and with a fairly light foot granted, but still better than I expected.

Mine has dropped another tenth to 11.3, but I do not care. I have a very heavy foot and love the sound.
If I want better mileage I can drive the Tahoe. It gets just over 14 .

Black Lingenfelter Lux

Texas Red...now there's a name I haven't seen for a long spell...how've ya been bud?

I've heard that the 2004 has different engine programming than the 2003?

Any truth to this?

Any official word from GM?

ya, 14 mpg overall? RIGHT. Only if being towed! There is no GM literature stating any changes in MPG, and if there were any change for '04 you can bet your ass that GM would have advertised that up one side and down the other, since mpg is the greatest weakness than the public can come up with for the H2.

gasman

I did expect people to think I was exaggerating. I'm waiting for other '04 owners to chime in.

I just got to drive the wife's 04, w/ 400 miles it seems more responsive than the 03 w/7000 miles.
The wife also made the comment on the way home after trading that she thought it ran better.

The 04 is showing 11.6 mpg and the 03 took months to get to 11.4 mpg.

Yell'r 04 Lux w/ air, sunroof,F&R brush bars
Traded 03 White Lux
03 GMC D/A CC SLT LB soon to be 04

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>if there were any change for '04 you can bet your ass that GM would have advertised that up one side and down the other, since mpg is the greatest weakness than the public can come up with for the H2.
<HR></BLOCKQUOTE>

No, GM can't advertise that. The fuel economy figures are not posted on window stickers, because only the EPA can rate for MPG, and the EPA will not test the H2. So any improvement in MPG has to be determined by the owner. It's just that GM can't say anything positive or negative on MPG since the EPA doesn't test.

I have heard that the Vortec family of engines did receive some airflow modifications to their basic structure, and the engine in the H2 is a Vortec. Not a full generational change in engine technology, but at least an "improvement" I doubt that it's a programming change in the main computor or TCM, but it could be worth looking into your TCM chip for improving performance.

Nobody expects the Spanish Inquisition!!

My average is showing 11.1 mpg. My mileage improved on my '04 with the headers, exhaust and cold air intake. I have yet to install my Xtremeflow software upgrade. Hopefully I will get up to 12 mpg.

04 H2 Engine upgrades by Rod Hall Racing
02 BMW M3 Convertible
95 Ferrari F355
01 Ducati 748

Just to join the opinions I have a 2003, very early production. My average according to the meter is 10.8. This is 50/50 (Highway) and I consider myself to have a LIGHT foot. My calculations are always about 2 mpg higher.
Straight highway I calculated 15.5 at best. I just wonder how accurate theses GM meters are, should we trust them, I would suggest to calculate your own milage.
On another note I am looking into programmers and exhaust systems. Pretty confused on which to go with. Any suggestions? Thanks in advance!

Doug
2003 Metalic Red H2
Adventure Series. w/navigation/Sat Radio/Winch

3500 miles on mine and its dead on 11.1 and that is mostly back roads with lots of hills. Also quite a bit of start and stops. My Silverado averaged about 13-14 on the same roads. The Escalade is 13.6.

03 Sunset H2!
89 Vette
02 Escalade