Here is some real world information when it comes to coax cable. I also hope to expose what in my opinion may be a few myths.
Most mobile radio installation will use RG-58 Coax. It's thin, easily tucked and pliable. For short runs it does not do too bad. It's pretty much the standard for mobile antennas.
Here comes the myth. Sometimes you will hear people claim, "The thin RG-58 coax cable is fine for base station installations less than 100 feet". Sure it will work, but, the performance of the thicker coax is very noticeable. On cb radio for example, the static noise level is higher with the thin coax. (rg-58).
RG-8 vs. RG-213: Yes there is a difference. Livecbradio.com uses a 75 section of RG-213. When we switched from the thick RG-8U to Beldon RG-213 a difference is noticeable. One will surely not notice if the test is base on the first install. In my case it was run outside, change the coax and come back in and listen. Yes there is a slightly lower noise floor.
Once again, they will all work fine, but, "all coax perform the same" is far from the truth. In a 50 plus foot install, going to RG213 from RG58 is like night and day in the receive of the radio. It's not so much stronger signals as it is cleaner reception.