Automatic or Manual Transmission for Expedition Use?

[roving1]

Meh - autos do it all the time, what's the difference between putting my Ranger 10 speed tranny in 1st (4.69:1) vs a modern cruiser with a H55f (4.84)? It really has more to do with gear ratios than anything, right....not unique to manual vs auto, what am I missing?

Using the hill decent is just as easy brainless way to go about it, I thought it was stupid at first but after having it it's actually pretty nice.

I already said 10 speeds mitigate it somewhat but still not entirely because you have to get the rpm above the stall speed of the torque converter before there is any engine braking being utilised. Fall under that speed and its noticeable and and you may or may not convince the 10 speed to grab a lower gear but it makes it a lot harder because you have a narrower range of engine braking.

If you could manually lock up the torque converter down to idle then it would be great and I have driven hacked vehicles and vehicles with stand alone trans management where you could do this. It's all about the torque converter in terms of engine braking. With manual control there is no difference between the two and in the case of a 10 speed and more available gear ratios it would probably be better.

Hill descent that uses brakes isn't a solution for anything other than short term use. There is a reason heavy trucks have engine brakes and don't have some sort of magical hill descent that somehow makes the brakes have more capacity and longer life because you can't. Physics is physics.

This isn't just a truck thing. If you drive a crappy econo box in a really mountainous twisty road place like Mexico, Brazil, Europe etc the amount of engine braking you get between a regular manual or dual clutch auto compared to a torque converter auto is insane. I have driven identical spec cars other than the auto torque converter trans that start to cook the brakes driven in the same manner as manuals or dual clutch trans in mountainous twisty terrain.

 

[charlieaarons]

Meh - autos do it all the time, what's the difference between putting my Ranger 10 speed tranny in 1st (4.69:1) vs a modern cruiser with a H55f (4.84)? It really has more to do with gear ratios than anything, right....not unique to manual vs auto, what am I missing?

Assuming the 10spd has a lockable torque converter and can be locked in 1st gear.
The following is more relevant to medium and large trucks.
Allison automatic transmissions come in standard normal ratio (3.50 1st), wide ratio (4.70) and widest ratio 6.93 and 7.63 for the rare 3700 and 4700 series. With overdrive as tall as 0.64.
OTOH manuals with overdrive ~0.73 usually have 1st gear ranging from ~9.5 for 8 and 9 speed, ~12-14:1 for 10-18 speeds; the Roadranger 9ALL is 26:1! And many/most come with automatic shifting, lockable in any gear at drivers discretion. Just as easy to drive on pavement as an automatic even for someone with a damaged left leg. On rough terrain and for steep descent I will take 9.5-26:1 rather than 3.5-4.7 any time.
I have much personal experience with autoshifting manual gearbox.

 

[nickw]

Assuming the 10spd has a lockable torque converter and can be locked in 1st gear.
The following is more relevant to medium and large trucks.
Allison automatic transmissions come in standard normal ratio (3.50 1st), wide ratio (4.70) and widest ratio 6.93 and 7.63 for the rare 3700 and 4700 series. With overdrive as tall as 0.64.
OTOH manuals with overdrive ~0.73 usually have 1st gear ranging from ~9.5 for 8 and 9 speed, ~12-14:1 for 10-18 speeds; the Roadranger 9ALL is 26:1! And many/most come with automatic shifting, lockable in any gear at drivers discretion. Just as easy to drive on pavement as an automatic even for someone with a damaged left leg. On rough terrain and for steep descent I will take 9.5-26:1 rather than 3.5-4.7 any time.
I have much personal experience with autoshifting manual gearbox.

Lockable torque converter isn't needed if you have low range which generally gives plenty of control at low speed.

OTR trucks are different animals altogether, don't see that being discussed here? They typically have the 'granny' gears or compound low gears which are typically never called 1st but rather "L", it's not used unless you need to get a big load moving on a hill and can't see it being used downhill since the trucks are going 40-70 mph which is plenty for a torque converter to lock up with their jake / exhaust brakes....

 

[nickw]

I already said 10 speeds mitigate it somewhat but still not entirely because you have to get the rpm above the stall speed of the torque converter before there is any engine braking being utilised. Fall under that speed and its noticeable and and you may or may not convince the 10 speed to grab a lower gear but it makes it a lot harder because you have a narrower range of engine braking.

If you could manually lock up the torque converter down to idle then it would be great and I have driven hacked vehicles and vehicles with stand alone trans management where you could do this. It's all about the torque converter in terms of engine braking. With manual control there is no difference between the two and in the case of a 10 speed and more available gear ratios it would probably be better.

Hill descent that uses brakes isn't a solution for anything other than short term use. There is a reason heavy trucks have engine brakes and don't have some sort of magical hill descent that somehow makes the brakes have more capacity and longer life because you can't. Physics is physics.

This isn't just a truck thing. If you drive a crappy econo box in a really mountainous twisty road place like Mexico, Brazil, Europe etc the amount of engine braking you get between a regular manual or dual clutch auto compared to a torque converter auto is insane. I have driven identical spec cars other than the auto torque converter trans that start to cook the brakes driven in the same manner as manuals or dual clutch trans in mountainous twisty terrain.

Use low range, sure it will be above idle, just like when you are driving around the other 99% of the time.

Hill descent works great and it's a tool, using your extreme example of a 6 hr downhill, HDC is not the best solution, just drop it in 1st and/or Low Range which is highly dependent on the rig and gear ratios.

I don't fundamentally disagree with what you are saying which is why I said *may be better*, I was just objecting to manuals unanimously being better than autos.

 

[lugueto]

Lockable torque converter isn't needed if you have low range which generally gives plenty of control at low speed.

There you go. No need to overthink things.

I usually visit a mountain village down here that requires low range both uphill and downhill for about an hour uphill and an hour and a half downhill.

Land Cruisers reign supreme. I've visited my whole life, its a common weekend escape. I've visited driving a bunch of Toyotas, from old manuals to more modern autos and a lot in between.

In any manual vehicle, you descend in low 2nd. In any auto vehicle, you descend in low 1st. All of the 4 speeds are going to be a little quicker than the manuals, obviously, but they're still slow enough to not use brakes for anything other than sharp turns. 5 speeds are actually slower than manuals in low 2nd.

 

[SoyBoy]

Thanks for all the replies. I originally posted this and a bunch of other inquiries about 2 months ago. I took all the advice given and ended up doing a 180 and ended up buying a 2013 Tacoma Access Cab Automatic and will be installing an Alu-Cab Canopy Camper to it next month.