Originally Posted by stevejahr
Gear Vendors does not automatically give you a bunch of forward speeds... you have to crunch the numbers and see if the resulting ratios are different. I had an overdrive like this once and gears ran 1-2-2od-3-4-4od because 3od was about 0.01 different than 4th and just not worth the effort.
You can put in all the gears you want but if you don't got the torque you just are not going to get anything done. When it is all said and done it is torque moving you up the hill and you are only going to move as fast as you have the torque to make you go.
Good point S, like many have said it is torque that is missing and there is no substitute. You are wanting to pull a grade at a particular speed that might not be realistic. I messed around with some numbers... these are estimates only.
Lowering the gear to 3:73 is about an 8% change
4:10 around 16% change in RPM.
At 60 MPH you might now be turning 1700 rpm with stock gears
3:73 will get you about 1836 rpm
4:10 will get you about 1972 rpm
You essentially would be turning about what you now do in third (assuming a 4 speed) but be in 4th.
What you get is with change, the gears are closer, so the RPM drop of increase in a gear change is less. This will keep the RPM more constant and like someone said, get it moving easier from stop.
I guess your MPG will suffer about 4% worse with the 3:73 and 8% with the 4:10.
The cost of changing the gear set, isn't going to get you any more for the Burb when you sell it.