: 2012 Focus-S wheel upgrade


trumpy959
06-10-2012, 10:58 AM
Greetings and welcome to my first post

I recently purchased a 2012 Ford Focus S with 15" steel wheels that has approx 2100 miles. Im assuming there must be people out there that are selling there 17" Ford alloy wheels because they too are considering some type of aftermarket upgrade. I was wondering if I could run those 17" factory Ford alloy wheel's that came from some other 2012 Ford trim level on my 2012 Focus-S?

I was going to ask the dealer this question when I bring my car in for its first service check up and was wondering if he's going to tell me the sky will fall if I even consider such a thing. I understand that the car in its present trim level was designed for a certain size wheel but would this action effect anything at all in a negative way like for example the accuracy of the speedometer, or would it void any warranty?

Initially I wanted the Focus in its cheapest trim level but theres no doubt the profile of the car would look much better with a bigger wheel and probably even handle better as well. This would be a great way to save money on original factory Ford alloy wheels and tires if I were lucky enough to find someone considering such an aftermarket upgrade.

Thank's in advance for your help and advice

Geezer
06-10-2012, 12:08 PM
I'm not aware of any reason why you can't use a wheel that came from any other 2012 Focus on your car. They all use the same lug pattern and appropriate offsets for the Focus. Just remember that bigger wheels do not necessarily guarantee an improvement in handling (nor looks in my opinion but that's purely a personal matter). Bigger wheels (and bigger tires as a result) mean more rotating mass and un-sprung weight. Both can impact performance (acceleration, braking) and ride quality. There's trade offs that should be considered. Oh, and by the way.....welcome to FF!

trumpy959
06-10-2012, 12:36 PM
thanks Geezer

I was under the assumption tire circumference would be the same for both a 15" wheel with its approperiate tire versus a 17" wheel which I thought would have to run a lower profile tire. Of coarse the unsprung weight of a 17" wheel would have an effect on handling and performance but I really dont know anything about the physics of it all... thats why im here

Geezer
06-10-2012, 01:27 PM
You're correct regarding overall tire diameter. The goal is to have it the same overall tire diameter regardless of wheel diameter used. If I remember correctly your car has 195/65-15 tires. The stock 17" tire is 215/50-17. Both are close to being the same overall diameter (the 17 in this case is a few tenths of an inch larger, but not enough to cause any problems). As I mentioned above, the bulk of the weight (wheel rim and tire) is now a little farther from the hub. This increases rotating mass. Remember in science class when you spun an object on a string? As the radius increased the amount of energy needed to spin the object also increased as well. That's the main effect of increasing rotating mass. It requires more power to get it going, maintaining it, and then to stop it as well (braking is therefore impacted). As a result gas mileage can take a slight hit as well. The bigger tire and wheel (which is usually also heavier) causes the suspension to work harder. The shock absorber is now being asked to dampen more spring energy so it wears out a little faster. The shorter sidewalls of the lower profile tire will affect ride quality but the trade off is usually crisper handling (less sidewall roll). None of these impacts are terrible by any means for most street driven/daily drivers (unless you start going into much bigger wheels and tires). Many people will accept most of these trade offs when looks are high on there preference list.

RonMaiden
06-10-2012, 06:55 PM
I haven't seen any of the Ford rims for sale and they are way overpriced on ebay and of course form the dealer so the aftermarket is still the best option for wheels. I can get a new set of 17" with good tires for a little over a $1000 where it will cost you $1000 just for Ford wheels til you see more on the used market but they are still pretty rare.

trumpy959
06-11-2012, 07:39 AM
hmmm ... i always thought that alloy wheels were lighter and never even considered how the suspension and brakes will now have to work harder. My logic was that because the wheel is bigger its going to cover more distance with every rotation so I would actually get better gas mileage... again thats why im here because i dont know anything.

If what Ron says is true about the availibility and cost of these wheels, and after Geezers explanation which sounds to be a lot more accurate maybe a better choice would be to go with an aftermarket 15" wheel of some sort.

RonMaiden
06-11-2012, 09:22 AM
I'd still get a set of the 16" alloys since the cons won't be anything you'd notice except the looks which will be better.

Too bad you don't live closer I'd make you a deal on my very low miles wheels and tires since I'm going to 17"s in a couple of weeks.

I actually wish this wheel style came in 17" since I really like the design.
http://i206.photobucket.com/albums/bb284/v8spankr/P1020457.jpg

Geezer
06-11-2012, 06:09 PM
hmmm ... i always thought that alloy wheels were lighter and never even considered how the suspension and brakes will now have to work harder. My logic was that because the wheel is bigger its going to cover more distance with every rotation so I would actually get better gas mileage... again thats why im here because i dont know anything.

If what Ron says is true about the availibility and cost of these wheels, and after Geezers explanation which sounds to be a lot more accurate maybe a better choice would be to go with an aftermarket 15" wheel of some sort.


Alloy wheels are usually lighter than steel wheels for sure. Alloy wheels can vary in weight considerably, due to differing construction processes and materials, even if they are the same diameter and width. The key when changing wheels is to get the right size tire. The goal is to stick to the original stock tire diameter (or very close to it) regardless of the wheel diameter you use. For example, 195/60-15, 205/50-16, and 205/45-17 tires are all pretty much the same overall diameter even though the wheel size differ. Unless you re-calibrate your odometer, a tire smaller than stock size will run up more miles and a larger tire will run up fewer miles which can easily distort fuel mileage calculations. Your speedometer will also be off as it will read slower with the bigger tire and faster with a smaller tire.

Take a look at Tirerack's offering for your Focus. I'm pretty sure you'll find quite a few wheels in differing diameters for your car at decent prices. They sell tire and wheel packages with the tires pre-mounted and balanced and usually with a proper set of lug nuts for the new wheels as well. All you have to do is bolt them on when they arrive. Yes, bigger wheels (and tires) will probably cost more than smaller wheel diameter ones do. New stock wheels from dealers tend to be outrageously priced. Just buy from a reputable dealer as there are a lot of junk alloy wheels out there.

Sniperx
06-12-2012, 10:19 AM
I'm not aware of any reason why you can't use a wheel that came from any other 2012 Focus on your car. They all use the same lug pattern and appropriate offsets for the Focus. Just remember that bigger wheels do not necessarily guarantee an improvement in handling (nor looks in my opinion but that's purely a personal matter). Bigger wheels (and bigger tires as a result) mean more rotating mass and un-sprung weight. Both can impact performance (acceleration, braking) and ride quality. There's trade offs that should be considered. Oh, and by the way.....welcome to FF!There is no absolute. Larger diameter wheels and tyres can be lighter than stock steel wheels and the taller sidewall counterparts they replace thereby making the whole rotating mass point moot and even making rotating mass and unsprung weight better and lighter. In fact, I did a lot of research in my new tyre wheel purchase I am making next month and the T/W package I am getting is a whopping 10lbs per corner lighter than my stock 15in steel wheels and stock sized tyres. Also, a lighter wheel that is only an inch larger in diameter is no different in outter diameter mass than one that is an inch smaller in diameter that is heavier overall. Sure some wheels are heavier and diminish handling and everything like acceleration, braking, fuel mileage as well, but a lighter larger package has benefits over a stock wheel tyre package. I also think that going to even a 16 from a 15 depending on wheel design can make a car look 100% better than it does with stock steel wheels and hubcaps.

Sniperx
06-12-2012, 10:28 AM
You're correct regarding overall tire diameter. The goal is to have it the same overall tire diameter regardless of wheel diameter used. If I remember correctly your car has 195/65-15 tires. The stock 17" tire is 215/50-17. Both are close to being the same overall diameter (the 17 in this case is a few tenths of an inch larger, but not enough to cause any problems). As I mentioned above, the bulk of the weight (wheel rim and tire) is now a little farther from the hub. This increases rotating mass. Remember in science class when you spun an object on a string? As the radius increased the amount of energy needed to spin the object also increased as well. That's the main effect of increasing rotating mass. It requires more power to get it going, maintaining it, and then to stop it as well (braking is therefore impacted). As a result gas mileage can take a slight hit as well. The bigger tire and wheel (which is usually also heavier) causes the suspension to work harder. The shock absorber is now being asked to dampen more spring energy so it wears out a little faster. The shorter sidewalls of the lower profile tire will affect ride quality but the trade off is usually crisper handling (less sidewall roll). None of these impacts are terrible by any means for most street driven/daily drivers (unless you start going into much bigger wheels and tires). Many people will accept most of these trade offs when looks are high on there preference list.Let me ask this, or actually use an example. Say a stock steel wheel is about 20lbs or more in a 15in size, you buy a good quality aftermarket wheel made of aluminum that is 16lbs in a 16in size. How does the equation of rotating mass being heavier on the 16 work out when the overall weight is 4~6lbs lighter overall than the stock wheel. You description is accurate when the new wheel is heavier or the same weight but going from a 15 to a 16 makes so little difference it is negligible. Sure when a guy goes from a 15 to a 19 there is noticeable difference but not when it is done right and a slightly larger wheel and shorter sidewall tyre is used, and the overall diameter is the same there is little to no difference in the weight being nearer the outside of the package. As well, the lighter tyres and wheels are a benefit instead of a determent to the rotating mass and reciprocating mass since their weight is lo much less in the first place.

Geezer
06-12-2012, 05:06 PM
Better example.....it's possible to have two wheels the same diameter and the same weight and with one having more rotating mass than the other. It all depends on where the weight is located. Naturally the closer it is to the hub the better. But if the weight is predominately in the rim, the more rotating mass there will be. The biggest obstacle is that you don't know where the weight is when you buy a wheel so it makes it hard to compare them from that standpoint. I do agree that it's important to buy the lightest wheel you can afford and buy from a reputable wheel manufacturer because they understand how weight distribution affects performance.

Sniperx
06-12-2012, 05:14 PM
Better example.....it's possible to have two wheels the same diameter and the same weight and with one having more rotating mass than the other. It all depends on where the weight is located. Naturally the closer it is to the hub the better. But if the weight is predominately in the rim, the more rotating mass there will be. The biggest obstacle is that you don't know where the weight is when you buy a wheel so it makes it hard to compare them from that standpoint. I do agree that it's important to buy the lightest wheel you can afford and buy from a reputable wheel manufacturer because they understand how weight distribution affects performance.
I concur, and will say it is very easy to feel where the weight is on an alloy wheel which is more centralized, and a steel which has most of it's weight on the outer mass of the wheel IE: the rim as opposed to the aluminum wheel which has a far lighter rim and center.

Sniperx
06-13-2012, 10:06 AM
One time we were sitting around the shop BSing about un sprung weight and such and I spouted off about this topic. I restated my observations of a wheel swap on my BMW 2002 and how much it helped my handling and accel, stopping and so on. Everyone who wasn't engineer trained thoguht I was full of crap so we did a small experiment. We had a couple damaged wheels sittin round and decided to cut the center out of both and weigh the rim. The steel wheel was a 15x6, and the aluminum (off brand not even light by quality wheel standards was a 16x7. Needless to say, the outcome was surprising to all of us, even myself. The steel wheel rim only, not including any of the center weighed 14lbs, the rim of the larger diameter aluminum wheel weighed 7lbs......They all shut up after that. It proved that the centralization of the aluminum wheel theory was correct and that the idea of moving the mass further out on the assembly was not entirely accurate since the tires were the same exact weight in a 195 60 15, and the 205 40 17. And this was YEARS ago, like 1990. I'll bet most alloy wheels are a little lighter than these tested as well.

Geezer
06-13-2012, 11:07 AM
While that doesn't surprise me, especially when comparing a steel wheel to an alloy wheel, it would be interesting to see the difference in rim weights between an identical wheel in increasing (15,16,17, etc) diameters. I'm taking an educated guess that most of the weight difference between the wheels would be found in the rim portion of the wheel due to the increasing circumference. That's pretty much the basis for my argument that even though that once a tire is added to each rim, and the same overall tire/wheel diameter is maintained, the one with the bigger wheel will have more rotating mass (even assuming that the tire weights are equal).

focusstu
08-28-2012, 09:20 AM
Ford Parts web site lists a 2012 Focus 15" steel wheel and a 16" alloy at about 21 lbs. So the difference is not too great.

Geezer
08-28-2012, 11:32 AM
Is that actual weight or is that shipped weight? Too many places indicate the shipping weight.

Sniperx
08-28-2012, 11:37 AM
Is that actual weight or is that shipped weight? Too many places indicate the shipping weight.It's probably right since the EAPs and 5 spoke SVT wheels weigh in at a hefty 24lbs each! Which is why I opted out on them! Like mine better anyway and they were way lighter and cheaper than the EAPs and 5 spokes.

focusstu
08-28-2012, 01:19 PM
Is that actual weight or is that shipped weight? Too many places indicate the shipping weight.
I am not sure. I would guess it is shipping weight.

Geezer
08-28-2012, 10:48 PM
See some weights posted here: http://www.focusfanatics.com/forum/showthread.php?t=2278

I have a set of EAP's and they're closer to 20lbs (still porkey but not horribly so) than they are to 24lbs.

Sniperx
08-29-2012, 09:37 AM
See some weights posted here: http://www.focusfanatics.com/forum/showthread.php?t=2278

I have a set of EAP's and they're closer to 20lbs (still porkey but not horribly so) than they are to 24lbs.Did you actually weigh one? I am curious because I was going to buy a set and didn'
t trust the shipping weight so the seller weighed one on a bathroom scale and it weighed a tad over 23lbs.

RonMaiden
08-29-2012, 10:18 AM
I weighed my 16" OEM alloys before they were sold and I got 19lbs which wasn't too bad.

Sniperx
08-29-2012, 10:29 AM
I weighed my 16" OEM alloys before they were sold and I got 19lbs which wasn't too bad.Not really at all since a light 16 is in the 13~16lbs range.

RonMaiden
08-29-2012, 10:36 AM
For OEM that is pretty good still.

Sniperx
08-29-2012, 11:19 AM
For OEM that is pretty good still.Ford has a history of lighter stock alloy wheels. Like the second gen Tarus SHO I had, it came with 16s and they were LIGHT! BUT I hated the way they looked and went to a 17 that was as light....the Countour SVT came with pretty light alloys and so did some Mustangs. BTW the other attribute of an alloy wheel as opposed to a steel wheel is the load rating or strength, aluminum wheels are far stronger than a steel wheel for load bearing as well which is why many 4x4s and heavy duty haulers use them.