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Help my friend and I settle this argument

Pikers. Philistines. You should have wagered a six of Troegs. Mad Elf, I think. ;’)

You might put it in low if you are going slow down a steep hill but driving down the freeway at 70 mph you just leave it alone when you go down a hill. As has been said here, do not shift into neutral and do not hold the clutch pedal down.

I wouid like to see someone do an experiment on this question-----you know, bust a myth (or, not). Yes, put it to a test.
Take two identical cars, drive them down a long hill that doesn’t require use of the brakes. Put one car’s manual transmission into neutral, and the other car’s manual transmission into high gear. Start both cars at the top of the long hill and let them roll down to the bottom of the hill. Note which one arrives first, and by how much distance and time.
Return to the top of the hill and do it, again; with the cars’ manual transmissions gear position switched (to help rule out other factors).
Do the test, again, with one car in a lower gear ( to test the supposed braking effect of lower gears during descent).
Again, go to the top of the hill, and switch set-ups from car to car, and retest.

Well, the car in neutral will reach the bottom of the hill first. But it might be over the speed limit. The engine in the car in gear will hold it back some. The lower the gear the slower the decent. “I’m curious about this. When I drive down a long hill in gear, I’m riding the brakes the whole time” If you ride the brakes while “in gear” you would have to ride them harder “in neutral”.