What are the benefits of bigger tires?

[Howard]

Bigger as in increased radius, not tread width.

Here's how I see it:

Pros:

- absorbs more bumps
- acts like a shorter final gear (might be a con)
- inherently wider treads, better grip
- able to fit bigger brakes

Cons:

- heavier
- more unsprung weight
- higher polar moment of inertia
- more expensive (wheel + tire)

 

[NathanBWF]

Pro: They look cooler

 

[StageLeft]

Seems like you've got the pros and cons nailed out

People buy them cause they look good and that's basically it!

 

[Grey]

Pro
Looks much better then a wafer thin honda wheel.

Cons
Lower MPG

 

[Kalvin00]

nm

 

[geno]

- acts like a shorter final gear (might be a con)

You mean like a taller final gear. Bad for low end acceleration, but depending on how aerodynamic your car is and how much power it has, it can give you a higher top speed.

 

[BadgerFan]

Originally posted by: Howard
Bigger as in increased radius, not tread width.

Here's how I see it:

Pros:

- absorbs more bumps
- acts like a shorter final gear (might be a con)
- inherently wider treads, better grip
- able to fit bigger brakes

Cons:

- heavier
- more unsprung weight
- higher polar moment of inertia
- more expensive (wheel + tire)

If you go with a larger rim, you can decrease the sidewall to maintain the same overall diameter, thus not effecting the gearing. If you go with a shorter sidewall, it will generally be stiffer, thus transmitting more harshness into the car, especially on quick impact type situations, or tar strips. This also has the effect of letting the sidewall roll over less in hard corning, thus giving better handling.

Edit: Wow, thus used 3 times, thus that was a sweet post.

 

[Howard]

Originally posted by: geno

- acts like a shorter final gear (might be a con)

You mean like a taller final gear. Bad for low end acceleration, but depending on how aerodynamic your car is and how much power it has, it can give you a higher top speed.

Doesn't taller mean a higher ratio? But a bigger wheel would traverse a longer distance than a smaller one in one revolution, so the bigger wheel would have a smaller ratio, right?

 

[Feldenak]

There are pros?

Personally, I can't stand them.

 

[geno]

Originally posted by: Howard

Originally posted by: geno

- acts like a shorter final gear (might be a con)

You mean like a taller final gear. Bad for low end acceleration, but depending on how aerodynamic your car is and how much power it has, it can give you a higher top speed.

Doesn't taller mean a higher ratio? But a bigger wheel would traverse a longer distance than a smaller one in one revolution, so the bigger wheel would have a smaller ratio, right?

The ratio would be taller, I.E. 3.85:1 gears are shorter than 4.10:1 gears. 4.10 would be the "taller" of the two, meaning it's a larger gear to work through. Those number would translate into wheels too, 15" wheels would have a shorter ratio to the final drive, while say, 18's would have a higher ratio/difference...get it? The gear that's driving is physicall taller/has a larger diameter

 

[NutBucket]

There shouldn't be any problems with bigger wheels if you get a "plus" fitment. I went from a 14" steelie to a 17" wheel and overall diameter is about .1" different I believe. I went from a 185/70R14 to a 205/45R17. Additionally, steel wheels are heavier then they look so I figure the current combo may actually be lighter then what I started with. Naturally if you increase overall diameter then everthing I messed with. I saw a Suburban on the freeway once with those tiny azz wheels you see in L.A. It was going maybe 65 yet the speedo read somewhere around 100. Talk about zero gas mileage.

And the biggest pro was left out; greatly improved handling since you elminate the majority of sidewall flex

 

[boyRacer]

Originally posted by: NutBucket
There shouldn't be any problems with bigger wheels if you get a "plus" fitment. I went from a 14" steelie to a 17" wheel and overall diameter is about .1" different I believe. I went from a 185/70R14 to a 205/45R17. Additionally, steel wheels are heavier then they look so I figure the current combo may actually be lighter then what I started with. Naturally if you increase overall diameter then everthing I messed with. I saw a Suburban on the freeway once with those tiny azz wheels you see in L.A. It was going maybe 65 yet the speedo read somewhere around 100. Talk about zero gas mileage.

And the biggest pro was left out; greatly improved handling since you elminate the majority of sidewall flex

ding ding ding :beer:

 

[Zenmervolt]

Originally posted by: Howard
Bigger as in increased radius, not tread width.

Here's how I see it:

Pros:

- absorbs more bumps
- acts like a shorter final gear (might be a con)
- inherently wider treads, better grip
- able to fit bigger brakes

Cons:

- heavier
- more unsprung weight
- higher polar moment of inertia
- more expensive (wheel + tire)

Actually, they don't absorb more bumps, they absorb fewer bumps because they also have inherently lower-profile tires which means much less sidewall flex to absorb the bumps. However, for the same reason they give better response for steering because the tires' sidewalls flex less. Really though, the biggest benefit is the ability to fit larger brakes. Larger brakes don't really help you stop faster though. Larger brakes have better fade resistance, that's the real benefit.

ZV

 

[boyRacer]

Originally posted by: Zenmervolt

Originally posted by: Howard
Bigger as in increased radius, not tread width.

Here's how I see it:

Pros:

- absorbs more bumps
- acts like a shorter final gear (might be a con)
- inherently wider treads, better grip
- able to fit bigger brakes

Cons:

- heavier
- more unsprung weight
- higher polar moment of inertia
- more expensive (wheel + tire)

Actually, they don't absorb more bumps, they absorb fewer bumps because they also have inherently lower-profile tires which means much less sidewall flex to absorb the bumps. However, for the same reason they give better response for steering because the tires' sidewalls flex less. Really though, the biggest benefit is the ability to fit larger brakes. Larger brakes don't really help you stop faster though. Larger brakes have better fade resistance, that's the real benefit.

ZV

ding ding ding ...too bad they don't actually put bigger brakes... most of the cars i see with 18" wheels still have the stock braking system... while showing off their oh so trick looking drum brakes in the back as well.

 

[Zenmervolt]

Originally posted by: geno

Originally posted by: Howard

Originally posted by: geno

- acts like a shorter final gear (might be a con)

You mean like a taller final gear. Bad for low end acceleration, but depending on how aerodynamic your car is and how much power it has, it can give you a higher top speed.

Doesn't taller mean a higher ratio? But a bigger wheel would traverse a longer distance than a smaller one in one revolution, so the bigger wheel would have a smaller ratio, right?

The ratio would be taller, I.E. 3.85:1 gears are shorter than 4.10:1 gears. 4.10 would be the "taller" of the two, meaning it's a larger gear to work through. Those number would translate into wheels too, 15" wheels would have a shorter ratio to the final drive, while say, 18's would have a higher ratio/difference...get it? The gear that's driving is physicall taller/has a larger diameter

Uh, no. A 4.10 is shorter than the 3.85. In the 4.10, the transmission output shaft spins 4.1 times for every 1 revolution of the differential halfshafts. In the 3.85, the transmission output shaft spins only 3.85 times for every 1 revolution of the differential halfshafts.

Taller gears give less acceleration, more top end.

Shorter gears give more acceleration, less top end.

ZV

 

[Vic]

Good tire size calculator

 

[bleeb]

Originally posted by: NathanBWF
Pro: They look cooler

This is teh only reason I see to using bigger rims. Most racers will go with the smaller rims and MUCH better tires.

 

[Evadman]

I think the people in this thread are talking about 2 different things.

Wheel = Rim.
Wheel != Rim + tire.

If the overall tire/rim diameter stays the same, then the set will be less compliant. This means you feel more bumps, but you generaly get beter handling because the tire does not "roll over" itself. This handling must be carefully balanced because generaly a larger rim = more unsprung weight = crappier handling.

If the tire/rim combo gets bigger, this reduces your overall gearing which hurts accel, but gives you "more gear" on the top end, which if you can run yoru car to redline, the higher gear will move that redline higher up the MPH range. It will do absolutely nothing in top end if your car will not reach redline in top gear. It will lower your RPM per given MPH though, which may or may not effect MPG. If the combo gets too tall, the gear ratio in the diff will have to be lowered (higher numericly) to make up for the torque multiplication loss through the levergae of the larger tire/wheel.

The opposite is true if the tire/rim combo gets smaller in height.

 

[ElFenix]

Originally posted by: Evadman
I think the people in this thread are talking about 2 different things.

Wheel = Rim.
Wheel != Rim + tire.

actually wheel = rim + spokes + hub

 

[Howard]

Originally posted by: Zenmervolt

Originally posted by: geno

Originally posted by: Howard

Originally posted by: geno

- acts like a shorter final gear (might be a con)

You mean like a taller final gear. Bad for low end acceleration, but depending on how aerodynamic your car is and how much power it has, it can give you a higher top speed.

Doesn't taller mean a higher ratio? But a bigger wheel would traverse a longer distance than a smaller one in one revolution, so the bigger wheel would have a smaller ratio, right?

The ratio would be taller, I.E. 3.85:1 gears are shorter than 4.10:1 gears. 4.10 would be the "taller" of the two, meaning it's a larger gear to work through. Those number would translate into wheels too, 15" wheels would have a shorter ratio to the final drive, while say, 18's would have a higher ratio/difference...get it? The gear that's driving is physicall taller/has a larger diameter

Uh, no. A 4.10 is shorter than the 3.85. In the 4.10, the transmission output shaft spins 4.1 times for every 1 revolution of the differential halfshafts. In the 3.85, the transmission output shaft spins only 3.85 times for every 1 revolution of the differential halfshafts.

Taller gears give less acceleration, more top end.

Shorter gears give more acceleration, less top end.

ZV

Ah ha!

 

[BooGiMaN]

Originally posted by: NutBucket
There shouldn't be any problems with bigger wheels if you get a "plus" fitment. I went from a 14" steelie to a 17" wheel and overall diameter is about .1" different I believe. I went from a 185/70R14 to a 205/45R17. Additionally, steel wheels are heavier then they look so I figure the current combo may actually be lighter then what I started with. Naturally if you increase overall diameter then everthing I messed with. I saw a Suburban on the freeway once with those tiny azz wheels you see in L.A. It was going maybe 65 yet the speedo read somewhere around 100. Talk about zero gas mileage.

And the biggest pro was left out; greatly improved handling since you elminate the majority of sidewall flex

how were u able to see the speedo from ur car?

 

[FrustratedUser]

Originally posted by: BooGiMaN

Originally posted by: NutBucket
There shouldn't be any problems with bigger wheels if you get a "plus" fitment. I went from a 14" steelie to a 17" wheel and overall diameter is about .1" different I believe. I went from a 185/70R14 to a 205/45R17. Additionally, steel wheels are heavier then they look so I figure the current combo may actually be lighter then what I started with. Naturally if you increase overall diameter then everthing I messed with. I saw a Suburban on the freeway once with those tiny azz wheels you see in L.A. It was going maybe 65 yet the speedo read somewhere around 100. Talk about zero gas mileage.

And the biggest pro was left out; greatly improved handling since you elminate the majority of sidewall flex

how were u able to see the speedo from ur car?

It's his car!!!
ROTF.

 

[Ornery]

• Pros:
  
  - absorbs more bumps

This is reason enough for me to have larger sidewalls. My wife's car has narrow sidewalls on 16" wheels. Between that and the rest of the suspension, the ride is too stiff. It takes sweeping turns like it's on rails, and I appreciate that, but WHO CARES? How often in your daily drive does that matter? 5% tops? Give me the cushy ride every time.

Use the calculator to see what happens to your speedometer reading when you change the size of your tires and wheels.

 

[Lithium381]

I would assume you'd get slightly higher gas-milage...., well, if you do lots of highway driving. It takes more power to turn the larger tires, but once you're up to speed, you get more linear rotation for the same amount of radial rotation.....i've found that city driving my MPG goes down a bit, but when i do a lot of freeway driving, my MPG goes down....or it seems that way anyways, havn't calculated it out though.....and this is between tire sizes, i went about 3" more diameter on my new ones, i KNOW city mpg is less than highway...

 

[geno]

Originally posted by: Zenmervolt

Originally posted by: geno

Originally posted by: Howard

Originally posted by: geno

- acts like a shorter final gear (might be a con)

You mean like a taller final gear. Bad for low end acceleration, but depending on how aerodynamic your car is and how much power it has, it can give you a higher top speed.

Doesn't taller mean a higher ratio? But a bigger wheel would traverse a longer distance than a smaller one in one revolution, so the bigger wheel would have a smaller ratio, right?

The ratio would be taller, I.E. 3.85:1 gears are shorter than 4.10:1 gears. 4.10 would be the "taller" of the two, meaning it's a larger gear to work through. Those number would translate into wheels too, 15" wheels would have a shorter ratio to the final drive, while say, 18's would have a higher ratio/difference...get it? The gear that's driving is physicall taller/has a larger diameter

Uh, no. A 4.10 is shorter than the 3.85. In the 4.10, the transmission output shaft spins 4.1 times for every 1 revolution of the differential halfshafts. In the 3.85, the transmission output shaft spins only 3.85 times for every 1 revolution of the differential halfshafts.

Taller gears give less acceleration, more top end.

Shorter gears give more acceleration, less top end.

ZV

CRAP Got my numbers mixed up Yes, 4:10 would be a shorter gear, while lower numberical ratios would be TALLER

ugh, can't believe I screwed that one up