By on November 9, 2009

"13's are OK if you are going for stock or restored look but as you say 13" tires are getting harder to find and in my opinion just look too small. There are 14" wheels out there with 4 lug patterns that look good on a II but even 14" tires are getting limited in size. I now think 15's are the way to go and with the aluminum adapters converting 4 to 5 lug, just about any wheel can be made to fit the II. Tire choices in 15's are unlimited so the correct look can be had by doing your homework on backspacing and wheel width. A nice set of Cragar 5 spoke 15's would look awsome on the II or you could stager and put 14's on front and 15's on rear." (courtesy allfordmustangs.com)

Mike writes:

Sajeev, what ever happened to 14-inch wheels?  I mean, seriously, does the Caliber really need to be shod with 17-inchers? Why does my dad’s new half-ton pickup have 17-inch wheels? His old one had what used to be the industry standard 235-75R15. He about had a coronary when he found out new tires would be over $100 each. Perhaps if I put on my tinfoil hat, I’d say the tire companies are behind this. So really, does the average family sedan or minivan really need anything bigger that a 15-inch wheel/tire?

Sajeev replies:

Of course the Caliber doesn’t need 17-inch wheels: they can’t possibly fix Chrysler’s rolling abomination.  But let’s think about why every modern car has big wheels.

Speaking from an Engineering Standpoint: wheels over 15-inches provide space for bigger brake rotors (and calipers) and a shorter profile tire in the same tire diameter.  The benefits are better braking in extreme conditions, like mountain roads or any form of towing. Shorter profile tires provide more road feel and tread grip, completely changing a car’s “turn in” during the act of corner carving. In theory: most cars lose these benefits above 18” wheels, as more unsprung weight and rubber band tires make things worse.

Furthermore, modern cars/trucks are heavy, straddled with more gizmos, bigger (and taller) cabins and more rigid bodies. When you add more weight, you need more stopping power.

Speaking from a Design Standpoint: styling is a major factor in the mass-acceptance of larger wheels. By the 1980s, both the downsized American icons and Japanese entrants required a certain passenger volume without resorting to the bulk and shocking overhangs (front and rear) of previous decades. Which required a taller DLO (Day Light Opening) for more trunk space—among other things—and created a taller car in the process.  And, in general, taller cars naturally look better with “taller” wheels filling out their wells.

And big wheels were here to stay when Ford sold Explorer SUVs like buttered popcorn, making everyone ride tall in the saddle. Hence the need for taller profile wheels and bigger brakes merging with America’s insatiable need for sleek sheetmetal since the 1950s.

Maybe 15” wheels can make a comeback, but vehicles need to ditch their platform shoes and go on a serious diet.  I’m not holding my breath.

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45 Comments on “Piston Slap: Design Weak: Big Ass Wheels...”


  • avatar
    86er

    And, in general, taller cars naturally look better with “taller” wheels filling out their wells.

    Boy, you ain’t kidding.  The first few years of the 3/4 ton + GMT900s stayed with the 16 inch wheels and looked ridiculous.  That said, I’m more in the letter writer’s camp on this count.

  • avatar
    gslippy

    Somebody slap me before I go nostalgic for that Mustang.
    Sajeev, your reply is right on.  Bloat + styling = bigger brakes.
    As a consumer, it pays to know what you’re getting into when you purchase a vehicle with nice-looking wheels/tires.  Even some vanilla cars can be killers on tire prices, like the Honda Odyssey, which uses an odd size on its 16″ rims.

  • avatar
    PickupMan

    And I thought bigger wheels were to provide more room for bigger spinners.

  • avatar
    paul_y

    Real men roll on 15″ steelies (nor, incidentally, can afford anything else at the moment).

    • 0 avatar
      Via Nocturna

      Never mind the wheel covers. The whole affair could be simplified if the black steelies were simply coated instead with a metal finish instead of black paint, like on older Civics/Corollas/Subaru GLs.

  • avatar
    Nicodemus

    “The benefits are better braking in extreme conditions, like mountain roads or any form of towing. Shorter profile tires provide more road feel and tread grip, completely changing a car’s “turn in” during the act of corner carving”

    Really? Have you checked out an F1 car’s tyres recently?

    • 0 avatar

      Braking, steering and accelerating components between an F1 and a $25,000 car are significantly different. Especially when said car is loaded down with 4+ people and cargo, adding 40% or more weight to the platform. Which is impossible in a race car. Don’t judge a book by its tires.

    • 0 avatar
      Tommy

      I’m sorry but have you checked out an F1 car’s suspension assembly recently?  Or intake manifold?  Or seating position?  The thickness and give of the modern F1 car’s tire sidewalls is a racing necessity (both in specification and in suspension use), not at all comparable to road/domestic/street tires.

  • avatar
    FleetofWheel

    Hadn’t heard of the term (Day Light Opening) before.
    Yes, many vehicles are taller but the belt line has gone up even more resulting in less green house. The narrow gun slit windows seem to get narrower with each new product cycle.
    It’s sad that the windows on the rear doors of, for example, 90′s era Corolla are taller and emit more light than the windows on the front doors of many of today’s larger sedans.
    I guess outward visibility is not as important as looking cool and like you’ve got something to hide.
    I bet all the ‘sporty’ drivers who like today’s narrow slit side windows used to make fun of the opera port holes and ‘limousine’ backlights on the old Detroit land yachts.
     
     

  • avatar
    cdotson

    Four-word answer:  Four wheel disk brakes.
     
    Elaboration: Disk brakes and parking brakes don’t mix.  It’s very difficult to achieve sufficient holding force clamping a manual caliper onto a disk to achieve high enough hill-holding without requiring undue physical effort on the part of the driver.  Drums though, they’re easier.  Most rear-disks have under-hat drum parking brakes with a peripheral disk brake, requiring a large disk diameter to build up any swept area to speak of for actual braking, thus pushing up minimum wheel size requirements.

    • 0 avatar
      Forty2

      Volvo has had hidden parking drum-ettes for as long as they’ve put discs on the rear, on 14″ rims no less, so, no.
      Maybe the modern ones dispense with these, but my ’91 has them.

    • 0 avatar
      Vega

      I don’t think that’s true, just take my current ride as an example:
      BMW E30 325i. 4 wheel disc brakes with anti-lock braking. Top speed 137 mph. 14 inch alloys, 195/65 Michelin.

  • avatar
    slateslate

    I’d love to see the hubcap and steelies come back into fashion, though made with a lightweight alloy to compensate for the bulk.

  • avatar
    fincar1

    Bit of nostalgia here…I was really happy when I scored a pair of 1949-50 Merc 15″ rims for my ’48 Ford back in the day. I still think that those are really good-looking wheels, although when I got to looking at them closely they don’t have any symmetry, with three hubcap bumps, four slots between the two parts, and five lug holes. I suspect that it’s the unadorned functionality of them that I like. You can probably guess how I feel about dubs.

  • avatar
    Tommy

    It’s been ranted here before (I believe by RF) – huge wheels on SUV’s make their rotors seem minuscule.  Quite silly, especially as seen in motion.

  • avatar
    hurls

    What I’m nostalgic about (in a not so good way) is the time when you could get actual performance tires in smaller wheel sizes.
    If you’ve got an old Miata like I do and you don’t want to do a plus something conversion (and there are good reasons not to do so, including not just unsprung weight), well you’re down to about 1 or maybe 2 actual performance-oriented summer tires that fit.  Which sucks…

  • avatar
    carlisimo

    F1 cars are so far removed from regular cars that they hardly count.  Their tires need to be preheated to ridiculous temperatures just to work!  Their tire sizes are based on tradition more than anything else, and the tires are as much a part of the suspension as the suspension itself.  Road car suspensions aren’t designed that way.

    With bigger wheels and brakes to fill them, you get more brake cooling, which means you can brake more before they start fading.  This is why race cars based on road cars have giant brakes, and it does make a difference in the mountains or while towing.  And anything that real race cars have is instantly cool and must be emulated by drivers of sporty cars who wish they were racing.

    The turn-in advantage is real too, though it’s also a function of sidewall stiffness.  (F1 tires have very stiff sidewalls – it isn’t unusual to see a car that’s blown a tire limp back to the pits by driving on its sidewalls.)  I currently have 16″ Toyo T1-Rs on my Miata and they have relatively soft sidewalls, but the effect is more noticeable on Miatas with 15″ wheels than on mine.  At 17″ the turn-in is noticeably sharper, but the weight of those wheels makes the suspension work harder (harsher ride, even neglecting the shorter sidewall) and the increased rotational inertia slows down the car a tiny bit.

  • avatar
    alfred p. sloan

    Drum brakes (with the exception of parking brakes) are never coming back.

  • avatar

    It’s purely style. The big brake argument holds water when you’re talking about a GT-R with 15″ rotors or the like, but the average family sedan or SUV rolling on 17″s or 18″s has 11″ or 12″ pie plates that’d fit under much saner rolling stock.
    Example: Kia Soul Sport. 18″ wheels.  11.0″ rotors.

  • avatar
    Gardiner Westbound

    Big wheels are a styling fad that’s already on its way out.

  • avatar
    WaftableTorque

    My understanding is that tires with higher profiles provide more progressive feedback to the driver. The move to low profile tires does improve things like turn-in and absolute grip, but at the expense of at-the-limit predictability.
    I’m willing to bet a 1989 Miata is probably more fun to drive on its stock 15″ rims than a new Miata with 17″ rims for that reason, even if it’s slower.

  • avatar
    dejal

    Big wheels and narrow sidewalls on potholed roads are a match made in hell.   I’d rather have a bit more rubber in the sidewalls on a 15 inch thank you.
    By the way, FireFox crashed on my first attempt to leave a reply in your updated reply box.   I can’t remember the last time that happened (if ever) for any web site.
     

  • avatar
    ThisWas

    Question:  Why are tires for 17″ wheels more expensive than tires for 16″ wheels?  I can see why larger WHEELS are more expensive, but as wheel size goes up don’t we have less material in the TIRE?

  • avatar

    Additional, important points:
    Pro: Larger tires have more load capacity. Modern cars, and particularly modern minivans/trucks/crossovers, are heavy. 15-inch wheels/tires are often marginal for vehicles whose loaded weight may exceed two tons. (This was part of the problem with the Explorer; at the recommended inflation pressures, there wasn’t a vast margin between the Explorer’s ponderous weight and the load limits of the tires.)
    Pro: Even with smaller brake hardware, bigger wheels tend to provide better air circulation around the brakes to reduce fade.
    Con: Bigger wheels and tires are heavy, and their mass is part of the vehicle’s unsprung weight and the wheels’ rotational inertia, harming ride quality and, if the rotational inertia becomes extreme, hurting initial acceleration and braking response, as well. The effect of 18- and 19-inch wheels on the ride of otherwise compliant sedans is kind of like jogging in wooden shoes.
    Con: Big wheel/tire packages require more wheel well clearance, which means less wheel travel, again hurting ride. Depending on how much consideration the designers have given it, it may also impact turning radius by limiting the wheel lock.

  • avatar
    davey49

    Is the actual diameter of the tires any larger on these large wheel vehicles? or is it just a larger wheel and a lower profile tire?

  • avatar
    George B

    I like the look of 60 series tires on a sedan and the long, low, and wide era of car styling.  Most cars and truck built today would look better if you sectioned out several inches below the beltline to match the low greenhouse.  Wheel diameters of 20 inches and larger feel like a fad that has hit the ridiculous extreme on the hoopty.
     
    http://www.ebaumsworld.com/video/watch/80477861/
    http://farm3.static.flickr.com/2497/3750218551_76974cdb84.jpg

  • avatar

    I recall having 16.5 inch rims on an Econoline I had to buy tires for in the mid 90′s… I could only find one tire that fit that size; it was expensive, not that great of a tire and special-order to boot.  Enough of that noise, I said… I went and found some 16 inch steel rims for cheap at the boneyard, practically new, probably take-offs from a new rig whose owner just had to have some monster alloys or something.  I then had my pick of dozens of tires, right off the rack.  Not to mention that it beat trying to find a replacement 16.5 inch tire out in the boondocks somewhere, which is where my vans end up at least a couple of times a year.

    Which leads me to the point of this comment: A vehicle with oddball rim and/or tire sizes can be a nightmare if you ever travel out-of-town and have a blowout, especially if you’re off of the beaten path.

    It’s one thing to have weird-sized rolling stock on, say, a sports car, a project car, a hotrod or some other special ride… a certain level of masochism is part of that game.  But for a daily driver or something that you’re going to put a lot of miles on, and especially if you’re going out of town, why would you want to take on the added expense and grief?

    Let’s face it: If you put a wheel/tire combo on your car that’s heavier than what you already have mounted, you are doing it for style and style alone.  That’s fine, but don’t kid yourself that enhances performance… more weight sucks, and more unsprung weight really sucks if you’re looking for performance.  Paint some racing stripes down the hood instead, they’re scientifically proven to make your car seem like it’s faster.
     

    • 0 avatar
      starbird80

      A vehicle with oddball rim and/or tire sizes can be a nightmare if you ever travel out-of-town and have a blowout, especially if you’re off of the beaten path.
      A bit off-topic, but related:  a former roommate ordered a Ford Escort GT (1984-ish) with, among other options, the TRX tire/wheel package  He later learned that the wheel and tire size was not just oddball, but metric.  And of course, replacement tires were only available by special order from one manufacturer (Michelin).
      Adding insult to injury, the tires tended to wear quickly. He was told by a tire dealer that the TRX tire compound was optimized for running on…(wait for it)…wet cobblestone.  Great if you’re driving through villages in Europe.  Not so much in North America.

  • avatar
    johnny ro

    I like small rims and large tires. I like more not less suspension on crap roads I suffer on. I hate bent rims.
    My ’99 Miata has great turn in with 14″ all seasons.  Better than any SUV with anything. Just today on way home from work I mentally composed an entry for miata site, “who has gone up in tire size on 14 rims”. I stop by that site next.
    My 2002 A4 had 15″ standard, with no drumlet rear parking brake hiding inside the disc.

  • avatar
    Damage

    Before big wheels, you never heard about curb rash. Now it’s a household word, and you can’t parallel park anywhere without worrying about it because skimpy tire sidewalls give no protection.

  • avatar
    krhodes1

    There are VERY, VERY, few cars that NEED larger than a 16″ wheel to clear the brakes. That includes most European sports sedans, as one will note that 16″ is the usual recommended snow tire fitment. Anything larger is purely a fashion statement. The Kia Soul and Toyota Venza being the most egregious offenders IMHO. And the added cost is substantial at tire replacement time.

    My Mom’s new ’09 Jetta S came with 16″ steel wheels with plastic hubcaps for no good reason that I can imagine, given that previously the base Jetta came with 15″ wheels and drove the same. 15″ snow tires were about $30 each cheaper than the same tire in 16″, which more than paid for a used set of 15″ steel wheels to put them on.

  • avatar
    seeseebutler

    I had to sell a set of 14 inch chrome rims off a 73 Nova at a car show this summer. They were in excellent condition. You’d think I was trying to sell a rabid poodle. After scorn and ridicule from numerous vendors I finally found a buyer for 100 bucks — for all four.

  • avatar
    Funk Forty Nine

    @alfred P. sloan

    Drum brakes came back on my Mercury Sable.  My 97 had 4 wheel disks, my 03 has rear drums.  According to Edmunds.com the new Ford Escape also reverted to rear drums.  Are drums cheaper to manufacture than disks, or does Ford have a warehouse full of brake drums parts to get rid of?

  • avatar
    Robert Schwartz

    “vehicles need to ditch their platform shoes and go on a serious diet”
    Amen.

  • avatar
    skor

    That Mustang brings back memories…..of the really gross things I did to Farrah Fawcett’s  picture back in the day.

  • avatar
    Stephan Wilkinson

    I have 15″ wheels on a relatively modified–284 hp up from a stock 180–Porsche 911SC track car by choice, since I learn more by pushing those tires than bigger meats, and inside them fit 930 Turbo brakes, which are basically 2,000-hp “Hand of God” units, by brake-measurement standards.
    But I’m always amused by the bro’s who put 22′s on a S’clade with little tiny pie-plate rotors showing.  So stupid.

  • avatar
    YotaCarFan

    I think the lower profile tires are simply a marketing trick — bigger wheels make the car appear “sportier”.  They also conceal some of the overhang, allowing ever larger bodies to be built on a single platform that has a fixed wheelbase — having a bigger diameter shiny metal wheel that extends further to the front/rear of the vehicle gives the impression the wheels are pushed further to the ends of the vehicle.  So, to release a new, bigger model of car, the manufacturer simply uses the existing platform (same wheelbase), extends the front & rear of the car to make it bigger, and ups the wheel diameter to disguise some of the overhang.

    These big wheels “grind my gears” b/c they’re expensive as heck to replace, and are prone to popped tires and bent rims (and ruined bearings) when going over potholes, as happened to me with my 17″ stock Camry wheels.  Now I see Toyota is using 18″ wheels on their Lexus HS250h and 20″ (!) wheels on their V6 Venza.  None of these models are supposed to be “sports cars”, but the designers obviously want to make them look sporty since that’s what sells, even to people who want “grocery getter” and “Point A to B appliance” cars.

  • avatar
    imag

    It’s funny – I’ve seen a lot of discussion on this, but never anyone pointing to the car company that really started the trend: BMW.
    At the time, I remember the claims about sidewall compliance being the stated reason for their switch to rubber band tires, but they were really the original in mainstream production and the most obvious about it.
    I actually think wheels up to 19″ look fine when coupled with brakes that actually need the clearance.  Not so for donks of any sort.  I live in Oakland, and I’ve often been curious if many of these people, after buying 30″ wheels, realize to their own embarrassment that their car is now almost undrivable.  I’d also be curious to try to drive one for five minutes and see how bad it really is.

    • 0 avatar
      BuzzDog

      I’m not sure if BMW is totally to blame. GM had some part to play in this “my wheels are bigger than yours” contest, firing the opening salvo with the 1984 Corvette’s 16-inch wheels. Ironically, GM was also among the first to go down with their wheel sizes in 1957 (to 14 inches) to lower the overall height of the car; this was the model year in which Ford and Chrysler beat GM to the punch with their “longer, lower and wider” models. But I digress…but not before saying that it’s getting more and more difficult to find quality 13- and 14-inchers for vintage cars.

      The performance advantages of larger wheels sound good (larger brakes, lower unsprung weight, larger contact patch) but you’d have a hard time convincing me that it’s not simply a pissing contest.

  • avatar
    mrh1965

    What a great thread!

    I’ve been wondering about this too, and can only assume that it’s a tire company conspiracy.  Do people really know how much new tires are going to be for their shiny SUV with the 18” rims?  Not to mention the lack of durability.  I have a co-worker with a BMW and it seems like she is always getting a tire repaired / replaced at $200 or $250 a pop.  I was so happy to get a set of Michelin’s recently for my Passat and get out the door for about $450.  They’ll last for years.

  • avatar
    mach1

    DEJAL hit the pot hole exactly on target. My wife and daughter both have low profile tires on aluminum wheels. With road conditions what the are here  in S.E. Michigan, they’ve gone through about five rims at $300 a pop.

    • 0 avatar
      gimmeamanual

      Tell them to change their driving habits.  I had, and have numerous friends who have, aluminum rims w/low-profile tires (45- and 40-series) in SE Michigan and none of us are popping tires and bending rims.  I’ve never heard of anyone going through rims like that.  If I had to guess, I’d say speeding in low-vis conditions and following other cars too closely resulting in reduced reaction time/distance are key contributors.

  • avatar
    Spencer Williams

    I don’t have any big problem with people putting large wheels on their own cars, doesn’t affect me. BUT, when manufacturers create new models that are designed to wear big wheels, they look bad when wearing normal-sized tires, and it makes me cringe.
    Case in point, I have an 09 Mustang with 17″ tires on it. The wheel wells were made large enough to accommodate not only the stock 19″ wheels they offer, but the stock 19″ with snow chains on them. So, with my little seventeen inch stockers in there, the wheel gap is tremendous. And sure, I could lower the car to work around it, but I’m not going to sacrifice my car’s handling characteristics for looks. So I kind of look chumpish. Oh well.

  • avatar
    KalapanaBlack

    Explorers didn’t gain wheels bigger than 16″ until 2007.

    I always marvelled that my ’96 Galant with 15″ and 195/55 tires looked perfectly proportional, while the base G6s I was driving at work with 17″ plastic-fascia (or whatever GM called them) steelies with covers looked terribly under-wheeled. I now drive a car with 14″ alloys (’95 Infiniti G20) and it looks perfectly fine, too. It has four-wheel disc brakes with ABS, so I don’t buy into that argument. I think it’s purely style, with maybe a little revenue generation push from tire makers.

    Funny related aside – has anyone driven a current Chevy Impala LTZ or SS with 18″ wheels? The old W-Body can’t handle them, but GM jammed them on, anyway. Every single one I’ve ever driven, when taken around a turn with a bump in the middle, rubs the inner fender. I don’t see how this is safe. I was shocked at the under-developed feel of that happening at first, and have since become acclimated to it. Every single ones does it – even brand new ones with perfect alignment and less than a thousand miles on the odo.


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