RPM is a matter of gearing, not engine size or configuration. You would need a different transmission, or axle gears to change your freeway speed PRM, and changing either would probably mean a loss in the off road department.

 

I'd love a sweet 7-Speed auto trans mated to the current I5! After that, a nice I5 or V6 Diesel that can make some decent power without a turbo for maximun off-road control.

Oh, and a V8 for the rest of you!

 

ya i think swell hummer has them in stock

 

thats not entirely true, think about it..if that were the case then you no matter then every truck running the same gearing would have the same rpm/speed ratio as the h3. The revelution per minute of the rear might be the same but the tach mesures the motor rpms...which will change with each motor. A small block v8 will work alot less to get the truck to 70, thus will be turning a lower rpm. Sure changing the gear ratio WITH the stock motor will change engine rpm because it is taking less or more throttle to get the rear to turn to the desired speed. At the same time a bigger motor will also turn less to get the same gear ratio to that speed. Thats why most rice racers turn such a high rpm, not because of their gearing but because they develop their HP at a higher rpm range where a BB chevy developes its HP in a lower rpm band.When I sold my dodge ram dually I had a freshly rebuilt v10 motor sitting in my shop, with a lot of hours and blood a friend and I swapped it into his ram 2500 that had the v8 in it. I don't know where but he found an adapter so it would bolt up to his trans, During testing we were at 1250 rpm at 70 mph...his magnum v8 he said would have been around 2000. More displacement = less stress and lower rpms. His trans blew in two months but man it was a fun two months

 

This would only true in an automatic...Because you have the slippage via the tourque converter when power wasn't needed

 

thats true but in a manual the driver would be able to hold a higher gear longer with a sbv8 where a I5 would lose its power band and force a downshift.

 

And assuming the torque converter does not lock up. If it does, then when it locks, or with a manual, the engine will turn at a given RPM, which will turn the input of the transmission the same RPM, which will then go through a gear set and the RPM and power will get divided by the gear ratio then the new RPM and power value will travel to the axle ratio where it will be divided by that gear ratio, then out to the tires to give you a specific speed. If you change the tire size or any of the gear ratios, then you will affect the RPM and or speed.
Example: Lets go with an engine RPM of 2500, a top transmission ratio of 0.73:1 and an axle ratio of 3.73:1, which combine to be 2.7229:1 final drive ratio. The formula of RPM/ trans ratio* axle ratio(final drive)= RPM of tires. 2500/.73=3424, 3424/3.73=918(or simply 2500/2.7229=918)
The 285/75/16 tires that come with the adventure package have 614 revolutions per mile. If you multiply 918 by 60 you get the total revolutions per hour. If you divide that by 614 you will get the total miles driven in one hour.
918*60=55080, 55080/614=89.70 MPH

I know these numbers may not match what is indicated on the speedometer, but the gar ratios are genaric because I could not find the actual ratios for this example.

With a non locking torque converter, I don't think more power would equate to lower RPM because the load starting from the tires back to the torque converter would be the same, and therefore the slip in the torque converter would be the same. The engine would have an easier time moving it, that's all.

 

Not quite true buddy. There is even a formula to figure out your RPM based on your gear ratio's and speed. If everything else is constant but the engine the RPM's will be the same at a given speed.

 

RPM=MPH*gear ratio (or final drive ratio)*336/ tire diameter

 

Always glad to read the rumors, it just seems impossible that an 8 will be offered with all the 'fuel' considerations, unless we are burning something different by the 2008 H3 release date