Dear experts!
If someone has exploited both Hummer H3 with engines 3.5 and 3.7 liters, please tell me how fundamental is a difference of 16 kW in the behavior of a car?
Sorry my english

 

a few years ago i drove my friends 06,3.5 ,then bought an o7,3.7. i dont remember noticing a difference.
the 3.7,as i recall, was speced a little higher in hp,AT A MUCH HIGHER RPM.
im thinking if you drove a 3.5 on monday and a 3.7 on wednesday,you would not tell the difference!

having said that,i would still buy the 3.7 as it has a better reliability/service record as we have seen here.

 

Thank you for your answer!

 

Oh tom, I had to take you off of being blocked to see if you gave incorrect information. Well what did I find, your "recall" is INCORRECT!

According to the manufacturer specs from GM:
Vortec 3500 3.5L Horsepower: 220hp @ 5600rpm (SAE)
VS
Vortec 3700 3.7L Horsepower: 242hp @ 5600rpm (SAE)

Where is this "AT A MUCH HIGHER RPM"?

bg-m: The 3.5 and the 3.7 are both great motors. There are some 3.5s and early 3.7s that had head issues. Neither are going to win any drag races. That is not what the H3 was designed for. OffRoad, is where the Vortec I5 motors shine. As mentioned in many posts you can add a PCM tune, CAI intake, cat back exhaust and TB polishing to gain even better "#s" from either of the Vortec I5s.

 

TAINTER,
I do not want win any drag races
I live in Europe and I want to buy an H3. Now I have a choice - '07 3.5 or '07 3.7. A 3.5 is 3 000$ cheaper. Equipment is the same. And I'm wondering how much better is the dynamics by a 3.7 (without "tuning" of 3.5) and if I will not be sorry in a future that I saved these 3 000$.

 

My opinion is that the 3.7l will keep you happy and then you will never have wished for the larger motor.

 

At some point couldn't anyone always get a bigger bore size?

 

Great suggestion! But not until you can find pistons that will fit in the larger bores. When the 4.0L Jeeps first came out everyone was looking for more power and finally companies listened and created "stroker" kits for it that "punched" it out to 4.3L.

 

I thought 2006 was the only year for the 3.5L. Never heard of a 2007 3.5L. That said, I've no issues with my 2006 3.5L and it runs very well offroad in 4hi-lock with the trans in 2. I have recently added a GM performance air intake and can tell no difference. Merging onto the e-way is still a half mile exercise.

 

Flash,

And what is this GM performance air intake?
Did you install it yourself, or a specialist did?