Vibration above 40 mph stock suspension and tires

[BobMaxed]

Hello
New FiST owner here. I have a very early 2015 (04-14) that was owned by Ford till 12-15. They put 1700 miles on it . No clue what they did with the car. It was sold through an Auction and I bought it from a Ford dealer. I have never owned such a stiff car. My 2002 Miata was a GT car compared to this. I've been studying all the reviews and Forums so I knew what I was getting in to. BUT I think my car has a vibration that starts at 40mph that shouldn't be there. It doesn't matter how new or old the road is. Its not severe but its real annoying . The first tire place wasn't interesting in checking the car. The manager tried to convince me it was just the nature of a stiff suspension with 40 series tires. The second tire place I visited I asked them to check the balance and if there were any bent wheels. (Visually all the wheels looked good. Two tires have 8/32 of tread the other two 9/32) This place tells me I have one bent wheel. They send this wheel to a respectable local business that straightens aluminum wheels. I get the car back and it seems to be better. But it still starts vibrating at 40 and is still very annoying. It does help point out that I have one loose side view mirror. (no surprise there) The vibration does end at 55mph where before it continued to 70. I know there are ways of improving the ride and next spring I'll probably have 45 series tires on the car. But is there anything I should do now or should I just suck it up and enjoy it.

Thanks

 

[frankiefiesta]

Don't you have a warranty from ford? Bring it in and see what they say. Just my suggestion

Edit: my car does not do this no matter the tire. 40/45 series. 16 or 17 inch wheel

 

[BobMaxed]

Yeah I've got one year of warranty left but I suspect this is a wear or abuse issue. I had asked the dealer why this wasn't a Certified Ford, I didn't get a good answer maybe now I know. But it may be worth a try.
The DOT date on the tires is 41-13. So the tires are 2 1/2 years old. Maybe the rubber has hardened a bit. Temps here have been 40-50

 

[dyn085]

It just sounds like a wheel that's out of balance. I had a set of tires on my Jeep that kept going out of balance every 10-15k and the vibration was at around roughly the same speed. Did you already have them check that?

Edit: If it's still there, that's not my hyperlink.

 

[BobMaxed]

It just sounds like a wheel that's out of balance. I had a set of tires on my Jeep that kept going out of balance every 10-15k and the vibration was at around roughly the same speed. Did you already have them check that?

Edit: If it's still there, that's not my hyperlink.

Thanks for the reply. I had expected the 2nd tire place to actually balance all 4 tires. But all I got charged for was fixing the bent rim. Fort Wayne In. is big enough that I have plenty of options for suspension work. I guess I go somewhere else and actually get the tires balanced