Automatic trans and braking

RE: Beadandbeads-(touching the brake pedal)
I know the difference between a downshift and unlocking of the torque converter. If I didn’t the tachometer would tell me because it jumps up during a downshift. The Honda owner’s manual describes how the auto tranny downshifts automatically. Honda calls it “grade logic”. The tranny downshifts on downhills and on uphills it holds a gear longer to minimize hunting.

I think this can be dangerous advice!

I saw, then smelled, a U-Haul headed S out of Flagstaff. As I passed, I saw his front discs were BRIGHT orange in the twilight! I couldn’t manage to get him to stop, and he managed to get to the bottom ok, though I don’t know how.

We get all types here, including those with older cars, with 4-drums, etc. Quite a few cars would be UNSAFE on a steep, high-speed descent near max weight w/o engine braking.

Agree…on slippery surfaces you want the brakes to supply the braking force and not the engine; otherwise you defeat the intent of ABS. There are times on glare ice when your only friend is free wheeling to maintain steerage.

That was the reason we loved to race opur old SAAB two strokes on our Maine lakes…lift up on the gas and the tranny would free wheel allowing you better control. Free wheeling was built in to allow the two stokes to idle back to maintain oil mixture at idle and not seize up. Side benifit was increase steering control.

That’s the intent of abs…free wheel and non braking impulses to allow steering control. Don’t defeat it by engine braking on slippery roads. Exception is comp. controlled engine braking

I have driven quite a few two-stroke motorcycles and these engines just don’t have any compression braking to speak of. Close the throttle and these engines just freewheel. Back in the '60s when two stroke engines were starting to dominate moto-cross racing, people discovered that you could give a two stroke engine compression braking by opening the compression release used to make starting these engines easier. They even rigged up throttles that automatically opened a compression release when you turned it past closed.
Nobody does that anymore as the new generation of racers learned what brakes are for.

The fact that releasing the compression increases engine braking suggests that “compression braking” is a misnomer.

You are correct. My 05 Accord Downshifts very nicely deceling to a stop. Fine Honda engineering PCM and tranny.
At speeds above threshold, fuel injectors are cut off. No fuel to the engine. About 1100 - 1500 rpm fuel flows at idle rate. Lower NOX.
On long decels at idle, fuel is pulsed periodically to heat the cat.
Save gas save brakes.

You got me on two stroke motorcycles…the SAABs would give you some braking if you “release” the free wheel; at the expense of reduced engine life or so we all thought that raced them. I did have one (two stoke SAAB) seize up at 80 mph. Sure glad it was free wheeling at the time.
As far as motorcycles were concerned,mine was a Norton 750…4 stroke; So I know nothing about the two strokes.

Volkswagens or Audis with the DSG transmission down shift as the car slows down, even without touching the brake. It’s based mostly on speed, so manual downshifting to keep the brakes from overheating is still necessary when going down mountain roads.