fyrstormer

iTrader: (1)

If the clutch engagement is set high, so the clutch is able to slip even when the car is moving fast, then yes, the exact RPM at which the clutch engages will have an effect on fuel economy. If the clutch engagement is set very low, so it engages slightly above idle, then the exact speed at which the clutch engages will have no effect on fuel economy. Of course, setting the clutch engagement high enough to slip when the car is moving fast will also shorten the lifespan of the clutch shoe(s), generate a lot of heat in the clutch bell and pinion gear(s), and potentially melt the spur gear(s), so there are multiple problems with doing that.