this post was submitted on 12 Jun 2024
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[–] [email protected] 3 points 6 months ago (1 children)

What, so now you're trying to split hairs over the regulatory differences between the US and Europe to attempt to distract from the fact that you still haven't addressed making the following demonstrably false statements?

  • Your notion that automatic transmissions "need" active cooling that they "don't" have when in fact they do, and
  • Your claim that torque converters "can't" be locked during acceleration when they provably regularly are, and
  • Your claim that your engine "will stall" if the transmission can't "slip" even while the vehicle is already in motion. (Hint: Get your car rolling, don't touch the clutch, and take your foot off the accelerator pedal. Did it stall instantly? Did it stall when you got back on the accelerator, either? Of course it didn't, because inertia is a process that exists.)
  • Bonus points for blathering about "trying to slip the lock of the converter," which also makes no sense because that's not how torque converter lockups work nor attempt to work, nor has anyone proposed they work that way.

 

For the benefit of anyone else reading this, the difference in rated tow capacities between US spec and Euro spec vehicles is, as you have almost correctly observed, down to regulations and the trailer designs and not the tow vehicles themselves. There is no difference between the cars or their transmissions mechanically (nor the laws of physics -- anywhere on the planet, I guarantee it). European regulations have two critical differences between the US, to wit:

  1. Vehicles towing trailers are typically limited to ~60 MPH or the equivalent, whereas in the US they are not (at least outside of some specific state laws).
  2. Tongue weight requirements are significantly lower, because nobody owns a body-on-frame truck which is necessary to support a high tongue weight.

 

This is because it is dangerous to tow a low tongue weight trailer at high speed. America has no such speed or tongue weight restriction, and we also have interstates with 85 MPH speed limits. Thus our target tongue weight is roughly 15% of the total load, largely in order to keep the trailer under control at speed and prevent it from snaking all over the place and rolling itself and the vehicle. All other things being equal this ultimately winds up in the tongue weight being the limiting factor for most unibody vehicles. If your tongue weight is limited at e.g. 200 pounds, which it is for my bog standard Subaru Crosstrek, solving for the estimated tow capacity assuming 15% of it is 200 lbs would be roughly 1333 lbs. What's the US spec rated tow capacity of a Crosstrek? Oh wow, it's 1500 pounds. Imagine that. (For both the manual and automatic/CVT versions, by the way.)

FYI, we also have trailer brakes over here, and many states require them to be used on loads exceeding 3000 pounds. Below that, the trucks most people use have adequate mass and braking capacity to handle towing trailer loads in and of themselves. It turns out, the actual reason Americans tow with trucks is because Americans tow with trucks, and our towing regulations and trailers are designed around the expectation of towing with trucks. It's a just a cultural thing. No need to try to make it complicated nor make up fictitious bullshit about automatic transmissions.

But none of this has anything to do with your original assertions re: automatic vs. manual transmissions. I'm not arguing any other points with you.

As a matter of fact, I'm not arguing any more points with you at all. You have no idea how cars work. Go away.

[–] [email protected] 0 points 6 months ago* (last edited 6 months ago) (1 children)

Your notion that automatic transmissions “need” active cooling that they “don’t” have when in fact they do,

I'm saying that to pull heavy loads they need active cooling. And they do. They also have cooling when not designed for heavy pulling, but they don't need as much cooling because all the mechanics you literally agree with me over: More cooling is needed under heavier loads. This isn't some far-out concept it's physics, it's what happens when you put oil in essentially a blender, it gets hot.

Then, and this seems to get ignored by you: Americans aren't pulling heavy loads with cars. Why? Do you have an alternative explanation?

What’s the US spec rated tow capacity of a Crosstrek? Oh wow, it’s 1500 pounds.

1270 kg over here (with trailer brakes, 12% incline). That's nearly twice. Tongue weight: 80kg. That's less.

And that's a Japanese SUV. You can get VW Golfs with 1.8t towing capacity, that's a compact car. Also pure combustion ones, the Crosstrek is a hybrid it's easy to get low-end torque with one of those and transmission is a whole another topic.

This is because it is dangerous to tow a low tongue weight trailer at high speed. America has no such speed or tongue weight restriction, and we also have interstates with 85 MPH speed limits.

That's why trailer brakes exist and don't pretend 140km/h are fast... though with a trailer you're generally limited to 80 or 100 here, depending on make and whatnot. Maybe you should introduce speed limits, regulations for brakes on trailers, etc. Maybe you would if your small cars could even tow that much, physically. You should also start to use the left lane for overtaking only and get rid of those ludicrous amounts of stop signs and build your cities so that people can move in them, not just cars, but I'm digressing.

[–] [email protected] 0 points 5 months ago (1 children)
[–] [email protected] 1 points 5 months ago (2 children)

For a lorry, no. For a private vehicle, yes. Standard driving licenses only allow for up to 3.5t combined permissible weight (that is, vehicle and trailer plus maximum load), 750kg of those for trailer and load. If you want to drive a combination of vehicle and trailer individually up to 3.5t (so total 7t) you need a trailer license, anything above that you need a lorry license with all bells and whistles such as regular medical checkups.

Or, differently put: A standard VW Golf can pull almost thrice as much as most drivers are allowed to pull.

A small load for a private vehicle would be a small empty caravan, or a light trailer with some bikes. A Smart Fourtwo can pull 550kg which will definitely look silly but is otherwise perfectly reasonable, that's enough for both applications.

[–] [email protected] 0 points 5 months ago* (last edited 5 months ago)

Also, towing heavy, actually heavy, not 1200 kg, went away in cars about 1990. Emissions regulations, really. 1985 olds, Chrysler, could safely yank around a 4500 kilogram horse trailer. That all went away, now it's cars that could maybe 1000 lbs amd trucks that can pull 5 to 15000 kg loads. Btw, the old auto tow transmissions like the hydromatic 400, didn't have a lock up at all. Jaguar used to buy them.from Chevy for use in the old XJS v12s .

[–] [email protected] 0 points 5 months ago

What a sad country.