I have done
Pikes Peak in Colorado @14,100 feet..on a 900 pound touring motorcycle. It was a dirt road, and a challenge for a motorcycle.
I have also driven up Mt. Washington (@6288 Feet) in a '63 Chevy with
Drum Brakes...Scary coming down...and a much more recent four wheel drive pickup. The road is narrow.. broken up asphalt and alternating gravel and dirt. Let me tell you..Mount Washington is a MUCH more SEVERE Challenge than Pikes Peak.
At the top...Mount Washington is less forgiving..weather wise. However: We drove up through clouds, and at the last minute..the clouds blew away and we had Clear Blue Sky at the summit with unlimited visibility. ...It was COLD.

NB
PS: There were a few
Stanley Steamers (Antique Autos) at the top when we got there.