2013 FX4 w/Sony Premium sound system, if I put a 12 or 15 inch antenna mast on is it going to affect my reception? It looks so much nicer.

 

I put a shorter antenna on mine and I haven't noticed a loss of reception

 

I have a 12 inch. No loss in reception. I even get full signal in tunnels and parkades.

 

I think it could depend a lot on how far you are from the stations. I think the length helps with obstructions. I used to live 2 hours from Kansas City and got up on a dam (Milford) and I could catch one of the stations there with some static. My friend in his Corvette could never catch it. His antenna wouldn't come up to my windows.

 

yes it will indeed affect your reception. FM antennas are tuned for for efficiency by length. If you cut two inches off the stock one it will diminish quality but it may not be noticeable depending on how far you travel from the source. If you live in the city and rarely travel you may not notice or care. I put a cravenspeed stubby on mine which is like 4 inches tall and it killed my reception. I live 50 miles from the nearest station. It works fine in town but no dice out in the country. I have Sirius and never listen to fm so I dont care about it though, went strictly for looks and it looks awesome! A 12 inch one would work better than the cravenspeed but I couldnt say how much. I carry my factory one behind the seat just in case I ever want to listen to fm, which has been zero times in the last year and a half since I took it off, haha!

 

I have the 12" on mine as I drive my truck up to oilfield for work, I've yet to have any loss of reception compared to coworkers that drive and the company vehicles.