Does stretching a tire improve its lateral responsiveness? Or does the smaller contact patch offset any gain?
"Stretching a tire" means putting it on a rim that is wider than any recommended by the tire manufacturer. It is done as part of creating the "hellaflush" look,which is a stupid fad that seems to be fading away. Stick to the rim widths that are recommended by the tire manufacturer. Hellaflush stretching is unsafe and has no performance benefits.
Tyre companies spend $Millions every year designing tyres to specific sizes, to fit specific size wheels, with a big part of that size design being based on the operational safety of the tyre - including its side wall. There's a reason why they specify an upper wheel width limit rather than just stating: "Fits whatever width of wheel you can stretch them onto!" However, "Joe Bloggs" in his home garage, having spent no money at all on safety and performance investigations, naturally knows far more about tyre technology than the tyre companies do and so happily stretches tyres onto wheels that are too narrow, to make his car look "kool!". (Personally I think they look s:censored:t!)
I taking about controlling the side walls. I should have more clear. This post is for people with significant track seat time. Not fashion mavens or internet mechanics.
this is a good read: How to PROPERLY select and size TIRES for PERFORMANCE > MotoIQ - Automotive Tech, Project Cars, Performance & Motorsports
Maybe we don't understand your question. Can you be more specific about what you are considering doing?
You should post this is the Tire Stretching forum where fashion mavens, and internet mechanics don't visit.
I think people are misunderstanding your motivation for asking-- you are not asking about fashion. From the article referenced above: For ideal handling: when sizing a tire for a given wheel, I usually target a tires TREAD width to be as wide as the WHEEL width, or 0.5 narrower than the wheel width. From my personal experience working on and driving countless track days, time attacks, street cars and race cars, this typically optimizes the tires carcass for response and outright grip. It also gives the sidewall a very slight stretch or preload, which will improve the tires response and break-away characteristics. " So, yes, for optimal handling and steering feel the tire tread width should be the same or a little NARROWER than the wheel width ("stretched", as you put it). Most cars are produced with tires a little WIDER than the wheel because they might look cooler and provide more protection against curb damage, but for best handling it is not optimal.
There are three conditions: Tire sidewalls are straight up, Tire sidewalls tilt inward (wheel too small), and Tire sidewalls tilt outward. The first sets up the situation where lateral tire load is unaffected by static camber. The second sets up the situation where lateral tire load subtracts from dynamic camber. Strut type suspensions can use a "little" of this to good effect. The third sets up the situation where lateral tire load adds to dynamic camber. This is contraindicated for <well designed> double a-arm suspensions.
