SAN-PHX (massive tailwind) 190+ in a 172
PHX-SAN (massive headwind w/ lee side mountain downdraft, Vx climb) ATC asks what type aircraft, I respond CE-172, ATC says "Oh. You're doing about 10 knots GS"

Sometimes it would take an hour or more to push through that downdraft, in a Vy or Vx climb.