Why choose a larger tire size?

[Neil Womack]

I just bought a new Civic. I picked the LX trim level in part because it came with a 16" tire size. The DX trim comes with 15s and the SI comes with 17s.

I have no idea why I think bigger is better. Larger tires weight more and cost more.

What is gained by getting larger tires?

 

[SLCraig]

Generally less sidewall = less squirm and better handling. Although its not always true, if you have a super light rim with a really sticky tire, you could easily get the same results.

Reality is, on most modern cars, its MORE of a looks thing (with some aspect still going toward performance)

This is my 2 cents

 

[sciphi]

Pure looks. Some subcompact and compact cars do it to make the car corner better. Put sticky enough tires on a lightweight car and it'll rip through corners like a demon.

 

[Nick R]

Originally Posted By: sciphi
Pure looks. Some subcompact and compact cars do it to make the car corner better. Put sticky enough tires on a lightweight car and it'll rip through corners like a demon.


My car is a perfect example of this. the TTs have outstanding grip.

 

[Francois]

Good evening,

I went from p205/70r15 cheap & i think damaged Dunlop sp50 to p215/60/r16 Michelin pilot Exalto (more sticky tire). I thought that i would have better handling ( i did!) but i also made the assumption that i would had lost comfort. To my pleasant surprise, the soft compound is absorbing much more stuff from our very bad roads in the south of Montreal ... that's a really good experience for now The wider tire gave me much more stability. I dont feel like i'm in a boat absorbing "waves" from the sides

 

[Michael_P]

Japanese cars are known to read fast. At least the ones I have owned. For example, going from a 195/50/16 to a 205/50/16 made my speedo read accurate on the old Protoge'. Prior to this it was reading about 1.06 mile from mile marker to mile marker when the tires were new. After the tire change it was dead on. I could give other examples, but you get the picture. Bigger tires can handle bigger potholes. The extra width protects the rims from curbs.

 

[pidster]

I'm assuming we're talking larger rim size with same tire outer diameter (lower profile).

Lower profile tires absolutely handle better and feel firmer. They also cost more, are damaged more easily, and ride rougher. On my old Toyota I ran 195/50/15 in the summer and the stock 175/70/13 snow tires. Night and day difference. Handled on rails with the summers but slower, harsher, and harder to steer (no P/S on that car) If you spend the $$$ on super light rims you can remove the weight disadvantage but honestly the rims/tires were worth more than that car already lol.

If you're talking changing the OUTER diameter of the tire that changes your speedo reading and the effective final drive ratio of your car/truck that's got even more factors involved.

 

[EvanD]

larger rims slow your car down. Conering is a different story.

 

[Neil Womack]

I knew the BITOG crew would have opinions.

Thanks

 

[FusilliJerry82]

Originally Posted By: pidster
On my old Toyota I ran 195/50/15 in the summer and the stock 175/70/13 snow tires. Night and day difference.


Their being snow tires has a lot more to do with that.

 

[Audi Junkie]

More cushion = better ride and more able to support the car's weight.

 

[CapriRacer]

First, assuming all other things being equal, then directionally a larger rim diameter is going to result in a wider tire, which will improve the dry grip, the wet grip (except for hydroplaning), the steering response, but hurt the ride, the hydroplaning resistance, and the fuel economy.

The problem here is the "all other things being equal" part. Almost nobody does that - and differences in tires (other than size) can overwhelm any other propety.

Second, if we take "larger" to mean "larger load carrying capacity" then, all other things being equal (and this meaning is a little more complex), directionally this would improve fuel economy. You might get a couple of other changes, but it depends on which path you chose - aspect ration or section width - and one produces one effct and the other the opporsite.

- BUT -

If you take the opportunity a larger load carrying capacity tire presents and use a lower inflation pressure that results in the same load carrying capacity as before the change (again, assuming everything else is the same, and as stated earlier, the meaning is a little more complex), then you would only improve the ride.

 

[rpn453]

Originally Posted By: Neil Womack
I have no idea why I think bigger is better. Larger tires weight more and cost more.

What is gained by getting larger tires?


My tires (Michelin Pilot Sport A/S) are actually lighter in my 17" size (205/50R17 - 23 lb) than my 16" size (205/55R16 - 24 lb). I doubt that the 17x6.5" wheel is more than a pound or so heavier than the 16x6.5" wheel. All else being equal, a bigger wheel on the same tire width and rolling diameter shouldn't affect the weight much. You're just trading some tire sidewall weight for aluminum spoke weight. Going bigger does move the rim mass out from the center, so rotational inertia would likely increase, but only by a very small amount. I'd guess it's less than a pound in terms of equivalent static weight.

The larger size is more expensive ($159 vs. $131 on TireRack), but they sure feel nice in the turns. The 16" size would have more sidewall flex under hard cornering, but would benefit those who want a softer ride and those who drive over rough surfaces. So it's really just a matter of preference.

 

[ahoier]

My thought was "appeal" - so many people seem to be jumping on the big wheel bandwagon that started years back, my father says Snoop Dogg and those rappers started the phase, but I don't know lol....

But then, who knows, it takes a bigger tire, to keep a heavier car rolling and a lot of these luxury cars out there have curb weight of 3k LBS...don't know if a little 13" tire could support all that

 

[Hokiefyd]

Originally Posted By: ahoier
But then, who knows, it takes a bigger tire, to keep a heavier car rolling and a lot of these luxury cars out there have curb weight of 3k LBS...don't know if a little 13" tire could support all that


The tire itself probably could, but then you need brakes large enough to quickly stop larger masses, and larger wheels allow for larger brakes. Within reason, of course. Most vehicles with 18" and 19" wheels don't have brakes that large to clear, and the wheel size is largely cosmetic.

In fact, larger wheels do have compromises that are demonstrated in an article in this month's Car & Driver, where they directly compared performance of 15-19" wheels on a new VW.

 

[IndyIan]

Originally Posted By: FusilliJerry82
Originally Posted By: pidster
On my old Toyota I ran 195/50/15 in the summer and the stock 175/70/13 snow tires. Night and day difference.


Their being snow tires has a lot more to do with that.

Also inflating the high profile tire to more pressure can make it handle nearly as sharp as a lower profile tire at factory recommended pressure.
I've still got my skinny snow tires on at 38-40psi and they aren't too far off my normal all season tires in feel until I push them harder than most people would.