Contour Enthusiasts Group Archives Forums Modifications Wheels & Tires Do you agree?

I can't understand why some SVT's owners change their wheels from 16" to 17" and more.

First of all, when you increase the wheel diameter, in order to maintain the overall diameter you must decrease the side wall height, thus go to a lower profile. This means less rubber and thus less ride comfort.

I would prefer (and that's what I did) to keep the same 16" wheels and install 225/50/16 tires instead of the OEM 215/50/16 tires. This would give me wider tires, slightly larger side wall height and more rubber for more ride comfort. Even from the the aesthetic point of view, this would give me also a slightly larger overall diameter, in fact larger than with the 17" wheels. This would help to better fill the wheel wells.

The Focus SVT 17" wheels for example (that some CSVT owners are using) are equipped with 215/45/17 tires. If you go to wider tires, you should lower further the tire profile which gives you this not so aesthetic "bike look" with much less ride comfort.

What do you think?

P.S. Of course I assumed that you do care about the rubbing issue and the accuracy of the speedometer!

The performance increase with a 17" wheel is indisputable. (assuming the same weight) First off, lowering the sidewall helps with "sidewall flex". When I first put the BAT Suspension on my car I had the stock 16's on, I noticed an improvement in handling right away. Shortly afterwards I got a set of 17's with 215/45/17 tires, that is when I suspension REALLY came alive! It's like a whole new car now. If you were close I would put my stock wheels back on, take you for a ride, then change to the 17's and take you for a ride. You would notice a difference and change your tune real fast.

The drop-off in ride comfort when moving to a 17" package is negligible. Now going to 18" or 19" is another animal. In my mind, the 17" package is the sweet spot. Without a doubt, the 18" and 19" wheels look terrific; I think you will find that most owners who have gone to those sizes did it primarily for cosmetic rather than performance reasons. Most 18" and 19" wheels weigh significantly more than the stock 16"'s, and most of that additional mass is at the rim of the wheel, further inhibiting performance. A nice light, strong forged 17" X 7.5" wheel with decent-performing lighter tires (you would be surprised at the variation in tire weights between competing brands in the same size) is my idea of the ultimate setup for our SVT's.

It's not all about performance. If so, you wouldn't have bought a car that looks as good as the CSVT. Some choose to make it faster, some choose to make it look better, some choose a combo of both.

There is an obvious trade off between comfort level with different wheel sizes, but that's where personal preference comes into play.

If it's not your flavor of Kool-Aid, don't drink it.

A good 17" tire/wheel combo will ride better than a bad or average 16" tire/wheel combo. My Kosie/Pirelli combo rides waaaaay better than my last 16" E0/Yokohama combo.

And like previously stated...my steering has def sharpened up...road feel is up...I am very happy. Choose smartly and you can have the best of both worlds...

225 on 6.5" wheels look a bit bulgy, IMO, and also will not perform as well as the same tire mounted on 7.5" wheels.

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First of all, when you increase the wheel diameter, in order to maintain the overall diameter you must decrease the side wall height, thus go to a lower profile. This means less rubber and thus less ride comfort.

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Less sidewall does not necessarily mean less ride comfort, but you are answering your own question. Less sidewall is, in effect, a stiffening of the suspension, which people do for what should be obvious reasons. If ride comfort is your main point, don't do it.

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If you go to wider tires, you should lower further the tire profile which gives you this not so aesthetic "bike look" with much less ride comfort.

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I am somewhat with you, except that I think 17 inchers on this car are about perfect. I think you can go too far, aesthetically, with big wheels/thin rubber, but 17 is well within the "good taste" range.

Also, wider tires need a lower aspect ratio to keep the same sidewall height. The aspect ratio is a percentage of section width. Get it?

Finally, a tire with a lower aspect ratio puts more of it's rubber on the road. Think of a big, 70-series tire. Section width is measured at the widest point of those bulging sidewalls. Compare those sidewalls to the width of the tread. Now look at a "low-profile" tire. See how close the section width is to the tread width?

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I can't understand why some SVT's owners change their wheels from 16" to 17" and more.

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Well, if chosen carefully, larger wheels--especially if also wider--net you better and more precise turn-in, and higher overall grip, coupled with great looks, at a slight penalty in ride comfort in some cases. Even if it's not your bag, I hope you can understand that.

Well, thanks for your reply RogerB.

I also think that the 17" is as far as you can logically go for the CSVT (it is after all a sport SEDAN), with the 215/45/17 size tires for the CSVT.

But if you want to put tires wider than 215 mm on these rims, you have to go with the 245/40/17 tires!! I guess they won't fit on the CSVT.

So, I would be stuck with the 215 wide tires.

I would prefer the larger 225 tires on the 16" rims which gives me more rubber on the road as you say.

Some have had success with 225/45R17, which is not too far off the OEM tire height. It's imperative to get the correct wheel offset to avoid rubbing with this size.

Actually, I run 16x7.5 Kosei K-1's, which are lighter than stock SVT wheels by 4 to 5 pounds. The extra width would let you run those 225's on a rim more suited, and the weight savings would improve many aspects of performance, including ride comfort.

It's a thought.