What is proper tire pressure for most passenger cars?

I stop at quick lube for oil change- they say air pressure it too high… Maybe 35 -38 pounds. They lower it to 30.

Then I look on the tire and it says max press- 51 pounds!
What is it supposed to be?
Honda CRV…

Added (1). Okay- thanks for all the info. I got it now.
30 on the Honda…
On the old Volvo V70 its 32 front and 30 rear up to 500# weight of cargo and passengers.
And 38 all the way around for 500-1000#
Thats all cold tire pressure.

Should I get rid of my SUV?

I'm currently a sophomore in college and drive a 2007 Honda CR-V. I've been thinking about trading it down to a civic or accord because I'm a commuter student and have to drive thirty minutes one way to get to school. However my crv isn't in the best shape. The car drives fine but the bumper got ripped off and I just zip tied back on so I'm sure that would decrease the value a lot. It's a solid car, it has 102,000 miles on it and drives fine, but I always think about something with better fuel economy. I think it's worth like 5,000 so I would just trading it in for an older civic (2004-2007) with higher miles on it would be worth it? Or should I just keep my car and deal with the worse gas mileage. I would really like to be able to just trade in the car and replace it so I don't have to pay too much out of pocket

What's wrong with my CR-V CD changer?

I have a 2002 Honda CR-V. About a month ago, the 6 CD changer went out. It ate my CD s, and when attempting to load or eject a CD, makes grinding noises then goes dead. I bought one on eBay, used. When I plugged it up, radio works, CD player doesn't even register that it exists. Hit the CD button… Nothing. Complained, guy sends me another one. This one eats one of my CD s, then goes dead like the first. Guy sends me another one, this one plays awesome for an hour, then does the same thing, plays radio and tape player fine, but doesn't acknowledge the CD player.
Could it be my wiring, or am I just getting a bunch of junk CD players from the guy? I don't want to complain again if it's something on my end.

Does crawling up to speed use more gas?

I have been getting terrible gas mileage on my 99 honda crv and i've been driving slow and very paced, but i've noticed that when I drive normally and i get up to third gear my mileage somwhat improves.