I have a 2012 Gt Premium. I would like to lower my car and gain a little performance (I am not looking to do autocross or anything like that). I am going back and forth between a set of coilovers or just springs, shocks and struts. Does anyone have an opinion on either way?
Well coilovers are probably the best option in my opinion, but they are very expensive ,they do give you ride height adjustability so you can set it where you want it. Plus since you planning on replacing the Struts and shocks at the same time you are going to be spending a lot anyway. When lowering the S197 Mustang there are some other parts you will need. Out back,lowering the car will move the rear differential higher in relation to the body and could throw off the rear suspension geometry, cause the rear to shift slightly so it will no longer be centered under the car, and will affect pinion angle. How much depends on how low. The rear lower control arms should be parallel to the ground with the car sitting on the tires. If after lowering you see that the front where they mount to the body are lower than the rear, where they mount to the differential, you will need to get control arm relocation brackets (you should upgrade the rear lower arms as well, the factory arms are junk.) Because the car uses as panhard rod lowering will cause a slight misalignment of the rear again the lower you go the more pronounced. This doesn't adversely effect handling but the rear will be off center. To re-center the rear under the r under the car you will need an adjustable panhard rod, if you go lower than a 1.5" drop pinion angle can become an issue, and you could get a vibration at speed which will cause damage down the road, this can be corrected with an adjustable rear upper control arm. You can go on YouTube and see how to check and adjust the pinion angle. Again like the lowers the factor upper arm is crap and you should replace it any way.
In the front lowering the car will affect the camber, and there is no camber adjustment from the factory. Depending on how low you go you can buy camber bolts which gives you about 1.5 +/- of adjustment. My car is lowered 1.5" and they gave me plenty of adjustment. However that might not be enough if you really slam it . Then you will need camber plates.
Again this all depends on how low you go.
Are you running coilovers? If so, what type and how is the ride? Someone I know said that after an hour or so of driving the ride becomes uncomfortable and he recommended Koni shocks and struts with eibach springs.
I am not running coil overs. The Boss 302 comes from the factory with adjustable shocks and struts, and the car only had around 3500 miles on it when I changed the springs, so I could see replacing the shocks and struts at that point.. Other wise I would likely have went with coilovers.