serious discussion on wheels and tires do wider tires really

>>14090901
It's all conjecture without know the exact tire, size, air pressure, age, wear, and wheels you went from an to. There isn't a hard truth to this rule, some tires perform better in wider sizes and some it's pointless.

Interesting that bikes are going through this same thing, both road and mountain, and nobody can come up with actual answers. There's just too many variables because when you make a different size tire, even with the same sidewall and tread thickness, design, construction, etc. it's still not the same because of the dimensions of the tire so you can't say x variable does y. That is concerning width though, looks like your image is saying "wider" means taller sidewall aspect, one thing that isn't debatable is that a taller sidewall allows a larger contact patch because it can deform more. I don't think many people care about rolling resistance when upgrading, so yes people definitely do end up downgrading their traction by going to larger wheel sizes. Seems like the crazy low rolling resistance tires like the ones on the i3 have tall sidewalls anyway.

>>14090901
too many factors to just say "wider tires have less".

what larger wheels with shorter sidewalls DO do, is resist less potholes and give you a harsher ride. and I'm assuming the shitbox tires your previous owner put on to match the shitbox wheels were not too great anyway.

rolling resistance is so minimal anyway, you're going to encounter worse mileage due to friction on the highway for the larger wheel as well.

facts:
larger wheel means more contact with ground
more contact means marginally better traction and also friction
brand name high end tires mean more than the dimensions
your driving affects your mileage more than anything else
shorter sidewall means less dampening for bumps and hazards, and easier to destroy
the nicer the tires you get, the more likely you will to find nails in them

a tenth of a psi will do more for rolling resistance than 10mm of width and the compound/tread of the tire matters 10 times more than that.

Also, wider tires do not automatically translate into better grip in a straight line.

What it does do, however, is increases the liklihood that your tire is laying on a high spot which increases the psi of pressure on the tire at a specific point.

>>14090994
>the nicer the tires you get, the more likely you will to find nails in them

This. Forked out $800 for 4 studless snowtires.. Not 2 weeks later I have a nail in one of them.

>>14091261
>his tire shop doesnt give warranties

>>14090901
>do wider tires really mean better grip and better handling, with lower rolling resistance?

No, maybe and no in that order.

The amount of grip is determined by several factors, none of them have any relation to tyre (for god's sake learn the correct spelling) width, unless you are in an aquaplaning environment when as they have to displace more water with the same forces they are more inclined to aquaplane.

Handling is going to depend on the vehicle setup and what you consider "good handling" characteristics from your tyres. Wide tyres have a larger slip angle but also tend to have a less progressive brake away at the timed of the slip angle.

The wider the tyre the theoretically lower the rolling resistance as in your image but that assumes that you can simply make the tyre wider without making other fundamental changes to the construction.

>>14090994
>larger wheel means more contact with ground
False the normal force doesn't change, the ground pressure doesn't change thus the contact area must remain the same. (Or the car would move upwards as it would have imbalanced forces acting upon it.

>more contact means marginally better traction and also friction

False:
Fn is frictional resistance
Fn is vertical load from car
u - frictional coificent

Fr = Fn*u

The concept that friction is impacted by contact area seems to date back to a misunderstanding of primary school physics.

>>14091270
What place would consider driving over a nail a warranty issue? That's like driving your new car into a pole and expecting the dealership to cover it under warranty.

>>14091814
wider tires give more grip, that's not debatable lol

higher lateral force before slip = more grip and less heat

>>14091841
my tire shop will replace a tire for anything

>>14091848
No they don't, go away and read up a bit, there are plenty of good books on the subject if you want to improve yourself. If not don't post crap.

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>>14091848
>higher lateral force before slip = more grip

Doesn't understand the difference between slip angles and grip.

>>14091860
You're fucking stupid dude.. a wider tire has more contact area under an equal slip angle due to less relative deflection and load. that means more grip and less heat. it's fucking basic shit.

go drive your car with bicycle tires and let us know how it works out.

fucking hell. arm chair engineers please leave.

>>14091876
higher lateral force with less deflection at the same slip angle.
are you dumb? learn to read.

its common fucking knowledge that wider tires give more lateral grip to a point where theyre too big to react to load.
hence why theres tire sizes are a spec dimension is essentially every racing series ever or everyone would use the biggest tire possible.

>>14091814
so i can put bicycle tires on my car and it will handle fine?

it's the shape of the contact patch that changes with wider tires. it's the same area, roughly, under a given slip and load, but it's a better shape there's more of the contact patch at the leading edge, that means you can obtain more grip for a given slip angle and reach higher slip angles before grip falls off.

obv only to a point where suspension geometry is affected and the car can no longer be tuned because it doesn't react to load and youre adding lots of unsprung weight.

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>>14091882
>You're fucking stupid dude.. a wider tire has more contact area under an equal slip angle

No, just no. Try again this time put some effort into trolling, no one is that stupid even on 4chan.

I don't pretend to know what the fuck any of this means. I have faith that non-GM automotive engineers know what they're doing.

motoiq did a good article about this topic. find and read it

>>14092004
see: >>14091981

you're wrong. idk what to tell you other than good thing you're anonymous.

>>14091814
>Fr = Fn*u
This equation is both fit for purpose AND misleading. Tyre dynamics are horribly complicated, and friction coefficient is more complicated that just rearranging that equation.

>>14091814
>primary school physics
The friction model you are describing (static friction) is so heavily simplified for workability that it's almost useless for real-world applications. This is true of most academic physics.

I mean, the non-relevance of the contact patch size might hold up if you were trying to drag a car with locked wheels across a fairly smooth surface. However, static friction will not accurately describe the grip characteristics of a rolling tire.

>>14091841
my place does free puncture repairs for the life of the tire (as long as it is not in the sidewall)

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If you are talking about an instance where you'd put the exact same design of tires where one is something like 195 wide and the other is 235 on the same type of wheels, drive the exact same way under the exact same circumstances... not neccesarily

A lot of the grip of the tires depends on how much weight is placed on the tire. If you've got a superlight car and you put really wide tires on it then you might run the risk of the car actually being "too light" for the tires, meaning that the tires will not properly stick and quite quickly lose their traction under heavy acceleration and cornering, especially with stiff suspension

>>14091981

Correct, thankfully I'm not thy only one to have studied beyond kindergarten.

>/o/ - Physics

Most likely it's simply unsprung weight.
A heavier wheel tyre combo will handle mid corner bumps worse and be less comfortable. Your car will accelerate slower too. It's only ultimate grip which will decrease but those limits aren't probed regularly on the street and the OEM setup may be the best compromise for grip, handling and wear on components.

Then again, your OEM wheels could be bigger than necessary too in which case you could go even smaller.

Here op. This might help. http://caranddriver.com/features/effects-of-upsized-wheels-and-tires-tested

I think sticking with the stock type of wheel size is best. It's what the car was designed around. Why muck it up.

Got AWD, went from 205/55/16's Michelins, to 235/40/18's shit no name tyres, car now grips like shit.