I seem to have a feature that I can't quite find more documentation on. While going down a long hill, say over 50 mph, stepping on the brakes to slow down the vehicle results in a one gear downshift and holding at that gear. So far, this has been from OD to 4th gear. Is this a V8 thing only?

Nope, my V6 does the same thing. So does my 07 Civic. It's a downhill "logic" control to help you with braking/maintaining speed. I hate it. When I was much younger, I would shift into N, but that really isn't a good idea. Would be nice to have a defeat button.

Hmm, good to know that's it's a standard feature. I love it due to the fact that I tow a lot.

Thanks for the reply.

I think the gas pedal defeats it.

There's no tow/haul mode on the transmission because apparently it can sense the additional load. When you tow it should downshift like this more readily than if you are not towing, but I haven't tried it.

The 8th gen civic was great, but it worked even better (most of the time) if you used cruise control. You had to set the cruise 5-10mph below your target speed, but then once you reached that speed it would shift between 5, 4, and 3 as needed to maintain a constant speed down hills with non-constant grades. Except that sometimes it wouldn't do it and just kept accelerating. It's too bad it didn't have a shifter with direct access to 4th like we have.

Honda calls it Grade Logic, and Toyota calls it "with intelligence" (ECT-i).

i can attest to it downshifting both during towing, and when not.

the first few times it caught me off guard, I wasn't sure wtf happened. then a few more times, and I realized it was downshifting. I figured it was supposed to do that. THEN, I read about it on here, and confirmed it was doing as designed.