Originally Posted by
Mark Rinker
Actually, the 6spd did help...but most of us don't measure or record what it potentially gave us back...TIME!!!
It still takes the same amount of work (fuel) to propel the same mass down the road at the same speed, with the same 6.6L pump. Resistance is resistance, regardless of final gear ratio. In that regard, a 2002 LB7 5spd will be similar to a 2006 LBZ 6spd in fuel consumption, towing the same load, if you remove or factor out emmissions equipment inefficiencies.
BUT! If both trucks left on the same trip with the same load, and burned the same amount of fuel doing that same work - who got back to the shop quicker?
Ta-DA! The 2006 with the 6spd did! Time = money. There is more to efficiency than MPG can measure.
All the 6th gear (or 5th or 4th for that matter) does is give you more OPTIONS of keeping your engine at or near peak torque (read: peak efficiency) while you perform a certain task, at a certain speed.
With another taller gear available, we can do that same work, at the same efficiency, with slightly higher ground speeds.