and here's some science to prove it:
and here's some science to prove it:
I run a 205/50R15 tire on a 15x8 wheel, which is technically stretched. Does that make me silly?
In reply to NickD:
It depends upon the tire, because there is no real honest guide as to tread width measurements. Different brands, and even different lines within a brand may be significantly different.
Well, a Star Spec ZII 205/50 on a 15x8 definitely has some stretch going on
In reply to NickD:
That's nowhere near as bad as a E36 M3ty 205/50 all season on the same wheel. 
NickD wrote: I run a 205/50R15 tire on a 15x8 wheel, which is technically stretched. Does that make me silly?
I am sillier than you.
225/45 RS3s on 15x9 6uls
Nowhere near this:
My rule of thumb is you should be able to lay the wheel and tire on the garage floor and not have the aluminum rim touch the concrete. If it does it's stretched.
By that measure, my 17x7s with a 205/40-17 are stretched.
I stretched the temporary spare from a Miata onto a 14" 912 Fuchs wheel, to replace the incredibly heavy (and possibly useless) collapsible spare from my 911.
DeadSkunk wrote: My rule of thumb is you should be able to lay the wheel and tire on the garage floor and not have the aluminum rim touch the concrete. If it does it's stretched.
Your rule of thumb is outdated, in reference, to modern performance tires.
Tire stretch actually started on early drift cars as a way to make lower-powered cars able to break traction in the rear more easily. Funny thing is, pro drift cars have gone the opposite direction now. They are moving at such high speeds and running such massive amounts of power and steering angle, that they are searching for all the grip they can get and subsequently are running as wide a tire as possible and also running extremely low tire pressures. In fact, Formula Drift had to introduce rules that DQ you if you have a tire debead during a run, as it was starting to become a serious issue.
NickD wrote: Tire stretch actually started on early drift cars as a way to make lower-powered cars able to break traction
It goes back much further than that.
In his 1983 book Alan Staniforth talks about "stretching narrower tires on wider wheels" in the early 70's as a suspension tuning technique.
That and the lowrider crowd has been doing it for looks since forever too.
I was in Los Angeles in 1989 and remember seeing mini trucks and Corollas with 13 and 14 inch tires stretched onto impossibly wide wheels. I had never seen anything like it (pre-internet) and couldn't believe that they would actually stay on the rim. I don't like it at all, but I'm surprised that the idea didn't spread across the country sooner.
Worked for F1 in the 70s.
In reply to Appleseed:
Bias ply tires with soft side walls have little in common with modern radial tires with much more stiff side walls.
Needless to say, you don't see that sort of sidewall in modern racing circles and that's for a reason.
So much misinformation, where do I begin? tire stretching doesn't increase or decrease grip, it actually prevents sidewall flex, ensuring predictable handling on tires with large sidewalls.
In reply to Appleseed:
Are they Dirt Racing?
Trackmouse wrote: So much misinformation, where do I begin? tire stretching doesn't increase or decrease grip, it actually prevents sidewall flex, ensuring predictable handling on tires with large sidewalls.
It can decrease grip, when you take a car that had a 205-series tire from the factory and then replace it with a stretched 175-series. That is exactly why guys do it on low-powered drift cars
i always though that stretched tires came from people spending 1000's on wheels with the perfect fitment that realize they cant afford the matching tire because they are bigger, so they buy the cheaper skinnier tire and just started say "no man its the cool thing to do", and people followed.
edizzle89 wrote: i always though that stretched tires came from people spending 1000's on wheels with the perfect fitment that realize they cant afford the matching tire because they are bigger, so they buy the cheaper skinnier tire and just started say "no man its the cool thing to do", and people followed.
I kind of figure it's the opposite. They can't afford to pay 1000s for rims with perfect fitment, so instead of spending big bucks on custom wheels they get whatever is close enough, and then use the tires to make up for the lack of proper fitment.
Keith Tanner wrote: By that measure, my 17x7s with a 205/40-17 are stretched.
By that measure, a customer's 17x9s with 275/40-17s are stretched.
NickD wrote: Tire stretch actually started on early drift cars as a way to make lower-powered cars able to break traction in the rear more easily. Funny thing is, pro drift cars have gone the opposite direction now. They are moving at such high speeds and running such massive amounts of power and steering angle, that they are searching for all the grip they can get and subsequently are running as wide a tire as possible and also running extremely low tire pressures. In fact, Formula Drift had to introduce rules that DQ you if you have a tire debead during a run, as it was starting to become a serious issue.
I always heard it was in the German car scene as a way to run wider wheels, but keep the tires inside the fenders to meet the demands of the TUV.
z31maniac wrote: I always heard it was in the German car scene as a way to run wider wheels, but keep the tires inside the fenders to meet the demands of the TUV.
Same here, and that was 15+ years ago when people were still more interested in 18" wheels, bodykits, and subwoofers.
My personal experience is that a tire that is SLIGHTLY stretched feels sharper and quicker. Ultimate grip? I don't know and don't care. I don't autocross enough to really be concerned about it. I just like my car to feel a certain way. Wide tires stuffed on narrow rims feel mushy and soft.
You'll need to log in to post.
