I drink a lot of water every day. Not because I'm trying to stay hydrated but cause my throat always feels dry and it helps when i caugh. I have a couple of water bottlrs I fill with water and ice. Take it everywhere

Do you drink (a LOT of) fluids during the day? Your comparison with the oil in a car engine is spot on. Our "engines" - the Lungs - need a lot of lubricant too. Water can usually do the trick throughout the day. Especially at night.
My other favorites are teas, fruit juices, squishy fruits and soups. Either way, have as much as you like. Then one more serving. You'll know when you've had too much.
Your doctor can also prescribe other medicines which can help cut thicker mucus buildup. She will also say they should be taken with even more fluids. Be well.

You might try drinking more water. I think part of what you're experiencing could be dehydration. Lungs like things pretty wet!

I do lemons and or lime's too... Hot Teas, I like Hot broth too.

I'm always Dry and drink a lot of water.