Cary at CT Performance advised me to get a bigger tire along with new springs to improve ride/handling. I am hesitant to go to a bigger wheel and I was wondering if anyone has experience that would help my decision I'd appreciate it. The change would be from stock 16 to either 17 or 18. Thanks

 

I went front 16's to 20's, noticed basically no change in ride but handling got much better, less sidewall to roll over in the corners. Its not everyone's cup-o-tea but i like it.

 

I am running 18's with 35's for tires, and I love the ride. Believe it or not, but my Ex can corner fairly well with the large tires.

However, there is a balance when it comes to wheels and tires, a small rim and large tire can induce flex, and make the ride feel unsure and floaty in the corners. However, this set up can lead to a slightly smoother ride due to the rubber insulating the road from the vehicle.

On the other end of it, a large rim, with small tires (and side wall) will give less flex and provide a surer feel as Russ pointed out. However, less rubber can lead to a rougher ride, as there is less rubber to insulate the road from the vehicle, and a big bump could also lead to rim damage since there is a smaller amount of rubber to provide protection.

You should be fine moving up a few rim sizes, but the final feel and performance is up to you. Good Luck!

 

Thanks for the info guys. I guess I should have mentioned that I currently run 285 7 R16 and am looking to move up to either 305 or 315 in whichever size rim I go to though.

 

I don't have first hand experience on the Excursion with rim size, but everything David said is bang on point. Personally I did the Jeep thing for 12 years, and that's where I experimented a lot with wheel and tire sizes. I ran primarily a 15" wheel from 31's, then 33's and 35's, all the way up to a 39.5" Iroc on my Cherokee's. The 35 was when I noticed a change in road manners over the smaller sizes. The straight-line and gentle curves were similar, however when the curves got a little tighter or emergency lane changes occurred it was a different story. There was a noticeable delay in sawing the wheel and the vehicle actually responding, and the best I can describe it is like a yank-strap. The kind where the recovery vehicle takes off *****-out and the rope stretches, the stuck vehicle barely moves and then flies out of the hole. The sidewall of the tire acts much in the same way when you get to a larger tire with a smaller rim. At higher speeds or more severe steering inputs there's a delay, the rig turns a little bit, and then it turns a LOT. The 39.5's I ended up running a 20" rim, and 17's in the 35's. It made a world of difference on road, and a smaller difference off-road.

Currently I have 315/75-16's on the Excursion. I too went through Cary and he strongly recommended an 18 for 33's and 20's for 35's. The main reason I didn't follow his advice was budget, I found 315's with 16's on CL for $400. After bombing around in it for a year now, I plan on moving up to an 18 when these tires need to be replaced. This decision was cemented in place after driving my friend's Excursion on 37's and 20's... It just felt more planted and sure-footed around sharper curves. Granted he has the ridiculous 'stanced' look rims on it, and I'm sure that contributes as well. Either way, for a primarily street driven vehicle that has as much weight as ours do, I would've found 18's if I had to do it over again the first time.

 

I runs 20's, IMO night and day from the 16's. I use the Ex for towing and it makes a big difference, In fact... I'd say the wheels and tires made the biggest difference regarding handling.

I've don all the V/b code mods and Caryt's suspension.

 

I'm running 285/18 tires. A major upgrade. But here's the upgrade a lot of people ignore or overlook: rim width. I went from the stock 7"wide rims to 9"wide rims. That's the lateral support that makes a huge difference, more even than the tires.

Apart from my 30mm sway bar, the wide rims with good tires was the biggest improvement.

 

I swapped a set of 305/70/16 on factory wheels out for a new set of 305/70/17. Although the sidewall ratio is similar, as mentioned above by JohnInCanada, there is a difference in the way she handles due to the increased width of the wheel I chose it is more stable. 17x8.5

Keep in mind your intended uses for your ex, towing you might be better with a larger rim and lower sidewall. I stayed with taller sidewall on 17's to maintain a good foot print when I air down to drive the sugar sand on the beaches here in NJ. You can play around with air pressures too