"win2tanker" wrote in message
oups.com...
Can car engines interfere with FRS/GMRS frequencies especially if you
are trying to talk to someone from a distance who is in a car with a
FRS/GMRS radio, I also heard that cars tend to shield RF waves. I
have had this problem with CB's.thx in advance

GMRS uses Frequency Modulation. CB is AM or ssb.

So your GMRS radio is not as susceptible to engine interference (ignition
noise) as CB radios.

FM radios have limiters which cut out the AM (noise) if the signal is strong
enough

Using shielded ignition wires usually removes all ignition noise. Other
noises such as fuel pumps, computer modules can also cause noise.

For noise abatement -- see URL
http://ac6v.com/opmodes.htm#MO

As for the car shielding radio waves -- yes to some extent, but lots gets
thru the windows,etc. Your cell phone is a good example.

Your best answer is to try a field test between two cars.

Your noise may vary
Good Luck -- CL