Does the 2004 engine perform slightly better than the 2003?

[Drag]

<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!!

[H2 Daddy]

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.

[Zing]

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

[Texas Red]

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

[DURAMAX TIM]

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

[89vette]

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

[mseeliger]

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

[AL MOORE]

Do you feel a good difference or bad?


.

"Follow the white rabbit..." Morpheus 1999

[Centerfire]

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

[Hum2]

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

[Texas Red]

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

[Zing]

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.