15" wheels on ST

Discussion in 'Fiesta ST Wheel and Tire Upgrades' started by Kalter, Jan 24, 2014.

  1. ryst

    ryst Active Member

    The only thing I can think of that might generate extra heat is the Torque Vectoring, which probably works overtime in the winter with all the limited traction on snow/ice (SO MUCH SNOW THIS YEAR IN WEST MICHIGAN ER MAH GERD).

    But given the size of the brakes on this car, and the weight. I highly doubt you'd have heat issues, even on 15" steels (I have 15" alloy)
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  3. Francois

    Francois New Member

  4. RodMoe

    RodMoe Well-Known Member

    Those should work just fine :) post up some pics when you can :)
  5. BRGT350

    BRGT350 Well-Known Member Staff Member

    something I have observed this week concerning overheating the brakes. My 2011 Fiesta and 2013 Escape have the smallest wheels that will clear the brakes for winter use. After a few days of driving, neither car has generated enough brake temps to melt the snow that is in the wheel. If there isn't enough radiant heat from the brakes to raise the temp to 32'F, I don't see anyway to get the brakes to the temp in which the brake fluid begins to boil or the pads start to fade. The rear calipers on the Escape don't even produce enough heat to melt the snow on the caliper. Unless you are desending down a large mountain and are on the brakes the entire time, I don't see anyway under normal driving to overheat the brakes in the winter with small diameter wheels. I am going to raise the BS flag on the dealer's comment concerning overheating the brakes with small wheels.
    jimclark, Smokin, Noah and 2 others like this.
  6. marc89gti

    marc89gti Active Member

    While I agree with you that running 15" wheels on the FiST for winter use may never cause issues. The information that I received from my dealer came from someone at Ford Canada's Winter Tire Safety program. My understanding from what my salesman told me was that the FiST was to get 16" aluminium wheels as part of this winter tire set due to clearance and heating issues because the brakes on the FiST are larger than the standard Fiesta. Ford was specially making these 8 spoke wheels for the winter tire safety program, I had to wait almost 2 months to get them as they weren't available when I purchased the car in late October. The dealer was very nice enough to give me temp set of 15" steelies and winter tires. If this clearance and heater issue is BS as you state then its coming directly from someone at Ford Canada. Just to be clear my understanding is that a 15" rim and tire combo through Ford's Winter Tire Safety program wasn't even an option. There is one other person in this forum that I know of that their Canadian Ford dealer gave them the same 16" wheels as me, most likely as part of this free winter tire safety program.
    Last edited: Jan 29, 2014
  7. BRGT350

    BRGT350 Well-Known Member Staff Member

    I would love to see some data showing brake temps based on tire size. I just can't fathom generating enough heat to cause brake issues with a 15" wheel. For the past 14 years I have been running the smallest wheel to clear the brakes in the winter on a number of cars and have never run into an issue with cooking the brakes. I have been on a road course for a snow race and had no issues with the brakes. If anything, I would bet the pads can't even get to their proper operating temp in the winter. Keeping them warmer is probably a good thing.

    Ford of Canada may have some special testing requirements that do not apply for the US market, and that could cause a difference. From my own experience, I have never had an issue with brakes overheating in the winter using small diameter wheels and snow tires.
  8. marc89gti

    marc89gti Active Member

    The more I think about it know I do remember the parts guy at my dealer also mentioning the speed rating of the winter tire. They wanted to get me a winter tire that had the same (W) speed rating as the summer tire. I told him I would never be driving that fast on winter roads unless I had death wish. Which might explain why the FiST supplemental manual recommends a 16" wheel and tire combo for winter. Quoting the manual it states "Tire speed and load ratings should match those of the originally equipped tires as closely as possible." Maybe that's why Ford Canada wanted 16" tires on there because the W speed rated winter tires may be more readily available vs 15" because 16" have the lower sidewall and most higher speed rated winter tires tend to be larger in diameter for the various sports cars.
  9. BRGT350

    BRGT350 Well-Known Member Staff Member

    from a legal standpoint, I can see why they want the same speed and load rating for the winter tire. The speed rating is silly, since nobody with half a brain would drive fast on snow tires. It is scary enough going the posting speed limit, let alone anything over it. I can see the fear of having low speed rated tires and some idiot goes 130mph and the tire comes apart and the dealer or Ford getting blamed. This is very plausible. The speed and load ratings probably have more deciding factors than the brake temp.
  10. RodMoe

    RodMoe Well-Known Member

    Just to be a devil advocate here you may not see "car" speeds that high but perhaps wheel speed on glare ice(spinning and hooning) might hit that speed. Other than that i don't see a issue.. just sayin
  11. BRGT350

    BRGT350 Well-Known Member Staff Member

    with TC on or in Sport Mode, the wheel would not be able to spin that fast. I would think you need 4th gear, wide open with TC fully off to get the wheel speed into the triple digits. I would list that situation outside normal operating parameters (hooning).
  12. RodMoe

    RodMoe Well-Known Member

    Yup glad you din't say it would never happen :) lol :whistling:
  13. jimclark

    jimclark Active Member

    If it's a free winter tire safety program we're speaking of, and I were in charge of it, I'd keep it simple and cheap. And no, you wouldn't have choices of 15 v. 16 inch wheels. You'd have a choice to take what's on offer or go elsewhere. I agree fully with those that point out the practical considerations leading to the conclusion that heat buildup causing problems for brakes, rotors, etc. is extremely unlikely [unless doing that long-way-down-the-mountain thing, perhaps]. Also, when making recommendations about such things, even if not for a free program, companies will often try to give a single, idiot-resistant recommendation rather than ranges of options that might be seen as encouraging stupidity.

    I didn't have a free option, but did choose to purchase a set of 15" alloys, pretty open design, with 185/60/15 winter tires for the ice, slush, and snow season. I've got about 650 miles on the car, mostly in-city, and had no problems at all, and am not worried that I will.
  14. Gpfarrell

    Gpfarrell Member

    My current winter package is a $175 set of 2008 Focus 15" wheels that came with mediocre all season tires.

    I'm scanning Craigslist for Blizzaks but it's very drivable on the all seasons as compared to the 17s.

    The TPMS light doesn't bother me a bit!
  15. rweidman

    rweidman New Member

    I was concerned with clearance and snow buildup inside the wheel with 15s. I can not see brake overheating in our climate a big threat unless you are pushing summer temperatures with 15s and snows. So far my Tire Rack Sport alloys and Blizzaks are performing well, except on slushy icy roads where the ST wants to slide too easily.
    RodMoe likes this.

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