I am a fan of brakes - and larger diameter brakes are better. That means large wheel diameter, which means lower aspect ratios. ie Wide!!
Suspension and shock technology has greatly improved over the years and the compromises of low aspect ratio tires aren’t as great as they used to be for the overall vehicle ride/handling.
Having said that: I think there is more differences in the tire design compromises than there is in size differences. I am a big fan of people being allowed to make their own decision as to what they want in tire compromises, and I think tire size is relatively unimportant - certainly not worth arguing over on the internet.
I guess I just prefer the ‘feel’ (for lack of a better term) of relatively narrower wheels and higher profile tires. There is a good YouTube channel that describes the concept of “self-aligning torque”, and how pneumatic trail helps center a wheel/tire from a turn. And narrower wheel and higher profile tires, with more of their mass centered on the line of travel, tens to self-center from turns faster than do wider wheel-tire combos, all else(same vehicle, same alignment settings) being equal.
Now to what you stated about larger brake hardware, and larger diamber rims to accommodate it, there is yet one bigger reason for the wider lower profile movement, the school from where I get the most vocal argument:
The school of looks.
Acres of shiny (or matted) wheel, wrapped in a 1-2 inch band of rubber passing for a tire sidewall, is just “so kewwwwl looking”!
Yes, until one hits a pot hole, or kisses the curb while parallel parking.
The arguments start where I state that I “would never change the size or proportion of where the rubber meets the road” only for appearances.
That statement has often gotten me private warnings on some forums, or outright bans!
Capri: I must confess that I feel I really am ‘not of this time’ and perhaps would be happier living 40-60 years ago. There was a TV time travel show, in the 1990s(?) called ‘Sliders’.
Saying that I would “not change a handling component for looks” is not something one should be disciplined on a forum for.
No names were called. No foul language or political statements uttered.
Just my views on the subject.
You, Volvo, have hated me since the day I appeared in these forums. I am fully open to discussing our differences, preferably in the private conversation feature provided.
Well I’m sorry if I unintentionally lumped you in with the wide-wheels-club.
I tend to ’ shoot from the hip’ how I feel about things, and some times there’s collateral casualties, in this case, you. And for that I apologize, it’s not intentional.
db: As I stated to Capri Racer, I sincerely believe I am from another time - perhaps when the names Kennedy or Reagan were headliners, and so the way things are in this time seem to me, to put it as nicely as I’m able to:
Actually, and yes, I am generalizing, Capri says there are cases where it is not so, but generally, in 60 percent of examples, wider wheels shod with lower profile rubber require slightly higher cold pressures to maintain the wider dynamic footprint they produce, compared to narrower, longer footprints.
My 2010 Honda Accord EX, with 50-series 17s, calls for 32psi cold, vs a base LX, which requires 30psi for its 60-series 16s.
Part of the reason for the EX higher pressure are heavier accessories, including both power moonroof and power drivers seat.
The cold pressures listed on the vehicle door frame were decided on by the vehicle mfgr. to accommodate gross(max) axle weight, plus anywhere from 10 to 30 percent safety margin. (That means a full passenger load, plus full gas tank plus luggage.).
Toward the lower end of that range is handling pressures, toward the higher end is for promoting fuel economy.
Average daily load (driver, plus significant other plus 3/4 tank of fuel) doesn’t even begin to tax the gross capacity. So over-inflating cold/undriven tires more than 1psi over door frame sticker values is purely preference, and not required.
Trying to compare different sized tires is always a problem. How do you compare things if more than one thing varies?
For example: If I want to compare wide tires to narrow tires, if I only change the width in the size - say 205 to 225 - I am also changing the overall diameter and the load carrying capacity.
If I try to adjust everything so I get the same load carrying capacity and can use the same inflation pressure, I wind up with the problem that sizing comes in increments (205, 215, 225 & 60, 55, 50, & 16, 17, 18) and the load carrying capacity comes out slightly different.
So care must be taken when selecting these sorts of comparisons.
Also on that plate is the tire size. They don’t list more then one tire size. If your standard size is the wider tire, then putting skinnier tires on - you’d want to increase the tire pressure. And the reverse if the standard size is the skinnier tire and you want to put wider tires on.
I’ve always said- the most dangerous combination is arrogance coupled with ignorance.
There’s another good saying- correlation does not mean causation. Someone earlier in the discussion stated that the skinnier tires produced faster ETs. Was it the skinnier tires or was it the smaller diameter wheel/tire combination that had a positive effect on the overall gear ratio for that powertrain? Or perhaps the lower unsprung mass? Or a combination of all of the above? Confirmation bias happens…
As usual, I appreciate Mustangman’s engineering background, experience and scientific approach to these arguments over- I read something on the internet and did my own research…
Yup! The New Yorker cartoon below originated during the Covid Pandemic, but it could certainly be applied to misinformation regarding tires, or virtually any other topic where uncredentialed people suddenly declare themselves to be… experts.
I read that earlier performance chart… A fairly small low power car with larger and heavier tires and wheels. 4 flywheels with a larger MOI requiring more power to accelerate. Plus the largest tire had a 3% speedo error which means the tire was taller and the effective final drive was numerically lower… Net result is a slower 0 to 60. The tire’s effect would be minimal. A shorter but just as wide tire on a lightweight forged wheel would likely be quicker!
Doing my part to get to @davesmopar 's 140 post prediction!
