H3 w/ V8 in near future?

[ChevyHighPerformance]

Originally Posted by HoKC

Do not think that the V8 has to mean less mileage. The new Tahoe is rated at 20mpg on the highway with a V8.

I agree. If you ever wonder why the H3 downshifts so much from 4th to 3rd, it's because of the shift speed versus %TPS data. Here is this data from a colorado I5 (which is very similar to the H3). It's complicated, but if you look at it enough it will break apart. Assume you are applying 19% throttle, you'll shift into 2nd gear at 17.9 MPH, then into 3rd at 32.6 MPH, then into 4th at 44.1 MPH. If you blip the throttle by about 12 - 13% (to 31% throttle) the H3 will kick down to 3rd. This is why the H3 downshifts so much - not saying good or bad design - just saying why it does. It takes a bigger throttle blip (20% or more) to downshift from 2nd and 3rd. With a 5.3L, the downshift %TPS can be moved higher and the upper gears (lower engine RPM and lower parasitic losses) can be reached at lower RPMs. I feel that the 5.3L could have the same or better fuel economy as the I5 especially with DOD. I'd even consider 4.11:1 diferentials and a lower low range gear for better fuel economy and the same off road gearing.

In short a V8 has the potential for slightly better highway mileage, that would be great. No way it's going to have better city or combined mileage though.

S.

[ChevyHighPerformance]

Originally Posted by Steve - SanJose

In short a V8 has the potential for slightly better highway mileage, that would be great. No way it's going to have better city or combined mileage though.

S.

This data is directly from the Chevy website for Silverado 1500 trucks. The 4.3 L V6 (195 HP, 260 lb-ft) 4x4 with a 4-speed auto gets 15/18 MPG city/highway.
The 5.3 L V8 (295 HP, 335 lb-ft) 4x4 with a 4-speed auto gets 15/19 MPG city/highway.

This is just one example of no loss in city MPG but better highway MPG.

Good to know about possible similar mediocre gas mileage with a V8. Key word is possible since Hummer aerodynamics and tire selections are unique which impact highway mileage. And all the 4wd trucks listed above have lower city mileage than the H3.

Note 2006 H3 EPA mileage (all H3's have 4wd as standard for a reason):

16/19 auto
16/20 manual


S.

[BigBill]

I was told by a friend of mine that the H3 will definitely get a V8 engine in Fall 2007. My friend works for GM in Detroit at the tech center, and he confirmed this information from the program manager for this line. Also there will most likely be another engine upgrade, E85 option, in 2010.

Bill

[blindzebra]

displacement on demand people!!!

[RubHer Yellow Ducky]

I read in a BLOG that the H-3 would get a Rotary Engine option in 2008

RYD

[f5fstop]

Originally Posted by BigBill

I was told by a friend of mine that the H3 will definitely get a V8 engine in Fall 2007. My friend works for GM in Detroit at the tech center, and he confirmed this information from the program manager for this line. Also there will most likely be another engine upgrade, E85 option, in 2010.

Bill

Friend is incorrect...fall of 2007 is not a correct date.

[BigBill]

What is the correct date then?

[BigBill]

Originally Posted by BigBill

I was told by a friend of mine that the H3 will definitely get a V8 engine in Fall 2007. My friend works for GM in Detroit at the tech center, and he confirmed this information from the program manager for this line. Also there will most likely be another engine upgrade, E85 option, in 2010.

Bill

I misquoted my own email and f5 corrected me on it!

July 2007 launch as a 2008 model.