I really like the M5OD its just that pesky tall first and reverse gear that makes it troublesome when towing. I don't mean to hijack this thread but is there any other option besides the ZF?Oh, no idea one could order a 4.10:1 in these. Good to know.
ZF is also a lot noisier and heavier. M5OD would probably yield similar economy due to internal mass differences. My S5-47 7.3 spec was around 180lbs dry.
Excellent information. I've always wondered why the RCSB guys report better fuel economy. This pretty much sums it up. Tempted to sell some bitcoin and buy a gear vendors overdrive. Basically selectable 3.55 or 2.73 gearing. Paired with a ZF would be pretty amazing having all 10 speeds.
I hope this isn't too off topic, but I was looking at a friend's recently acquired 1919 Model T yesterday. It had been updated with things to make it friendlier to drive, like a 12 volt alternator and a distributor in place of the buzz boxes. One thing that really intrigued me was an overdrive unit mounted on the driveline. It was a Volvo Laycock brand. Would this unit be beefy enough behind our sixes?
I've had that thought but still does not give you the low rpm cruise. The ZF with an overdrive gives you the best combination: granny first and reverse for towing and a 5th over ratio of .6:1I remember some guys talking about running transfer cases in 2wd vehicles so that they could have steep highway gears for mpg, but use "4Lo" for towing around town. Can't remember if they were doing it for Pre-runner type of trucks or what, but the same discussion came up on EcoModder as well.