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Why go wider??

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#1
Every car I've ever researched to build I've always heard go wider. Now, I get that wider gives you more of a patch for traction. Is this the only benefit? Do our cars gain much benefit over going any wider? I won't be using my car for track/autox, for now at least, so what would be the benefit of going wider? I like the OZ Ultralaggeras a lot but I can only find them 7 wide in 4x108. Would these be an upgrade due to weight savings? I want to make this car a suspension beast, more than what it is already, and I know wheels and tires are a large part of that. Any advice is appreciated!
 


Intuit

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#2
A "suspension beast"? If a softer ride that is more capable over high curbs and rough roads is desired, you'll want to go with a smaller wheel and taller sidewall.

Minus the taller sidewall, I suspect the wider tire might help protect the wheels better during heavy cornering over bumps.

I think most people's reasoning is as simple as the contact patch you mentioned. While wider may be better for every other driving condition to a point, the traditional consensus is that narrower is better for tracking through snow.

Stock vehicle isn't hard to break traction when accelerating or cornering. So wider may help with at the very least, straight-line acceleration and pulling out of corners.

Nothing I've stated is likely to be news to you though; and are probably just searching for some unconventional "wisdom" on the subject. Not sure that exists for the topic.

Particularly for snow and from personal experiences, tread pattern is THE greatest factor for traction. (rubber compound is of course a massive factor) While I noticed no difference from going 10 wider on a prior vehicle, I had massively different experiences going from one tread pattern to the next; on "all season" tires.
 


Hijinx

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#4
A "suspension beast"? If a softer ride that is more capable over high curbs and rough roads is desired, you'll want to go with a smaller wheel and taller sidewall.

Minus the taller sidewall, I suspect the wider tire might help protect the wheels better during heavy cornering over bumps.

I think most people's reasoning is as simple as the contact patch you mentioned. While wider may be better for every other driving condition to a point, the traditional consensus is that narrower is better for tracking through snow.

Stock vehicle isn't hard to break traction when accelerating or cornering. So wider may help with at the very least, straight-line acceleration and pulling out of corners.

Nothing I've stated is likely to be news to you though; and are probably just searching for some unconventional "wisdom" on the subject. Not sure that exists for the topic.

Particularly for snow and from personal experiences, tread pattern is THE greatest factor for traction. (rubber compound is of course a massive factor) While I noticed no difference from going 10 wider on a prior vehicle, I had massively different experiences going from one tread pattern to the next; on "all season" tires.
It seems counterINTUITive (lol), but a wider tire, at the same height does not necessarily improve linear traction. It will improve lateral traction. In our case a wider tire on our 17s is inherently taller, because of the limited size the OEM chose.


Some Guy On The Internet
 


OP
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Thread Starter #6
It seems counterINTUITive (lol), but a wider tire, at the same height does not necessarily improve linear traction. It will improve lateral traction. In our case a wider tire on our 17s is inherently taller, because of the limited size the OEM chose.


Some Guy On The Internet
So are you saying wider isn't necessarily better? Suspension and the way changing tires/wheels effecting our cars is a weak point of knowledge for me. Would going to a 16 be a better option then to combat the increased height? I know some of the bbk on the market have to utilize a 17 wheel and I really want to go that route if I go big turbo/increase power greatly. Thanks for the help!
 


Capri to ST

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#7
I don't believe in going wider because I want to save unsprung and rotational weight, and a wider wheel (and tire) of a given type is heavier.
 


jeffreylyon

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#8
Going wider with a given tire size will improve turn-in and, maybe, ultimate grip. A good rule of thumb is to match the section width of the tire to the wheel width for the best feedback at the cost of ride quality. When the wheel is wider than the tire section you run the risk of unseating the bead (minor unless you really stretch the tire or really push the car). When the section width is larger the tire will squirm more, reducing stability while increasing ride quality.

In the FiST we're limited quite a bit by tire height; we have options with a 17x8 (215/40 or 45) but, from what I can see, squeezing in a 17x9 doesn't make a whole lot of sense because there are no street options in 225/40 and 235/40 is getting too tall to fit in the rear without grinding away some sheet metal.

As a point of reference I went with 17x8 with the OEM tires (they're rated to mount on a wheel as wide as 8") and there was a big difference in response. I did not notice reduction in ride quality but that probably had to do with the fact that I took 8# of sprung weight off of each corner with the wheel upgrade.
 


Hijinx

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#9
So are you saying wider isn't necessarily better? Suspension and the way changing tires/wheels effecting our cars is a weak point of knowledge for me. Would going to a 16 be a better option then to combat the increased height? I know some of the bbk on the market have to utilize a 17 wheel and I really want to go that route if I go big turbo/increase power greatly. Thanks for the help!
It's not cut and dry, black and white. Wider tires = more lateral (side to side, corner carving) traction. Taller tires = more linear (straight line, drag race) traction.

And of course, tire composition is a huge factor. A sticky 215/40-17 increases height a bit and adds some width. You'll need to look at the tire specs as not all tires are created equal by those markings.

I run 17s and 15s, so I'm not aware of all the options for 16s.


Some Guy On The Internet
 


M-Sport fan

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#10
What limits us the most as far as 16s go is that most, if not all, wheel manufacturers flat out REFUSE to make wheels for our ride in a 16" diameter, and 8" width. [mad]

Now, this is fine IF you are doing H/S class autocross, as 16x8s are verboten there, and there are some great choices in 16x7s for this car, but for those of us wanting the wheels for street, or open track use, without any rules dictated size limitations, the 16x7 is NOT ideal (CANNOT functionally use a 225/45-16 on a 7). [:(]
 


BRGT350

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#11
tires are the only thing touching the ground, so a wider tire means a wider foot print and more contact patch for traction. Tire compound, tire pressure, scrub radius, unsprung mass, rotational mass, and aerodynamic drag are all elements that need to be considered. A 185mm wide autocross r-compound tire will have vastly more lateral traction than a 255mm LRR all-season tire. A drag tire will have more acceleration traction than a street tire, but less lateral traction due to sidewall and tread construction. It is also to size wheels and tires accordingly to support the sidewall properly. In general, wider is better, but it is only one part of a very lengthy equation for what is the best solution.
 


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Thread Starter #12
tires are the only thing touching the ground, so a wider tire means a wider foot print and more contact patch for traction. Tire compound, tire pressure, scrub radius, unsprung mass, rotational mass, and aerodynamic drag are all elements that need to be considered. A 185mm wide autocross r-compound tire will have vastly more lateral traction than a 255mm LRR all-season tire. A drag tire will have more acceleration traction than a street tire, but less lateral traction due to sidewall and tread construction. It is also to size wheels and tires accordingly to support the sidewall properly. In general, wider is better, but it is only one part of a very lengthy equation for what is the best solution.
And the best solution is what I'm trying to come up with. Sigh, this is tough. I REALLY like the O.Z. Ultralaggeras but I can only find them in a 7" wide wheel. If they came in 8" wide I'd be all over it. I'm also looking at Rota Grids in 17x8 and Fifteen52 Tarmacs in 17x8 but both aren't that much lighter than the stock wheel. I know I will never do a lot of road racing/tracking but I also want to build my car as effeciently as possible with the time, money and parts I invest into it.
 


jeffreylyon

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#13
And the best solution is what I'm trying to come up with. Sigh, this is tough. I REALLY like the O.Z. Ultralaggeras but I can only find them in a 7" wide wheel. If they came in 8" wide I'd be all over it. I'm also looking at Rota Grids in 17x8 and Fifteen52 Tarmacs in 17x8 but both aren't that much lighter than the stock wheel. I know I will never do a lot of road racing/tracking but I also want to build my car as effeciently as possible with the time, money and parts I invest into it.
I hear good things about the Fifteen52 wheels, but they're pricey (I think) and heavy. I do not hear good things about the Rota's.

If you're willing to do a 4x100 conversion you should take a hard look at the 6UL's - very good reviews, quite light, and well engineered. Enkei and others have some interesting wheels in 4x100, too. If you want to stay on 4x108 then TD's probably offer the best combination of options, quality, and weight.

The O.Z.'s are good wheels, for sure, but they don't offer too many options in 4x108 and they are a tad on the pricey side.
 


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Thread Starter #14
I hear good things about the Fifteen52 wheels, but they're pricey (I think) and heavy. I do not hear good things about the Rota's.

If you're willing to do a 4x100 conversion you should take a hard look at the 6UL's - very good reviews, quite light, and well engineered. Enkei and others have some interesting wheels in 4x100, too. If you want to stay on 4x108 then TD's probably offer the best combination of options, quality, and weight.

The O.Z.'s are good wheels, for sure, but they don't offer too many options in 4x108 and they are a tad on the pricey side.
What is this 4x100 conversion you speak of? I haven't heard of this.
 


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#16
IF you are leasing your car, OR have plans on ever selling it with the factory wheels (you have to go through the whole process of switching back the wheel studs AND explaining to the new owner those extra holes in the hub flange) this is NOT a good idea. [wink]

Otherwise, I guess one could sell their factory wheels and use the 4x100s for as long as the car lasts.
 


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#17
IF you are leasing your car, OR have plans on ever selling it with the factory wheels (you have to go through the whole process of switching back the wheel studs AND explaining to the new owner those extra holes in the hub flange) this is NOT a good idea. [wink]

Otherwise, I guess one could sell their factory wheels and use the 4x100s for as long as the car lasts.
When returning the car for a lease, they will never check for that, and it is not visible.

When selling the car, you can just tell them what it's for, and it will probably help you sell the car.
 


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#18
Btw, I'm the guy that does the 4x100 conversions. PM me if you are interested.

 


BRGT350

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in terms of efficiency, a 8" wide wheel is the opposite direction you want to go. It is wider, most likely heavier, offers more aerodynamic drag, requires a wider tires which is also heavier and has more drag. Heavier wheels and tires require more torque (both acceleration and brake) to overcome inertia. Require additional damping due to the unsprung weight increase. I would go with a 7" wide wheel and a very aggressive tire compound. Take the money saved and go to a driver's school and find out that with better techniques, you won't be running out of traction with a 7" wide wheel and a 215mm (or even a 205mm) wide tire. On the street, you should never even come close to overcoming the traction of the stock ST. On the track, you should be working on practice and driver education and not lap times. Fast lap times are 90% driver and 10% car. Go for a ride in a production car with a professional driver and you will see what I mean. One of the most incredible rides in my life came from a car with 140ish horsepower, but with a professional driver. No tire size in the world could give me the amount of traction that is gained from a driver who understands exactly how to control a car.
 


jeffreylyon

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IF you are leasing your car, OR have plans on ever selling it with the factory wheels (you have to go through the whole process of switching back the wheel studs AND explaining to the new owner those extra holes in the hub flange) this is NOT a good idea. [wink]

Otherwise, I guess one could sell their factory wheels and use the 4x100s for as long as the car lasts.
It'll take longer to reinstall the stock intercooler, brakes, turbo, radiator, etc. that it would to knock out and reseat 4 studs per corner. The holes are a complete non-issue from a safety standpoint and only become an emotional issue if you feel the need to pull a wheel and point them out.
 




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