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.