Wheel/tyre size for best grip? Anyone help?

mxslide · Post by **mxslide** » Fri May 30, 2008 5:54 pm

Hi all,
Ive been looking around the net with no luck, and was wondering if anyone knows the theory behind wheel and tyre sizes, for maximum grip.

Like does a 205/50/15 grip better than say a 205/40/17? I realise that the 15 SHOULD have more side wall flex being a higher profile, but I dont know how many times I have heard people say that 15s are the premium for grip... (does a slight sidewall flex allow for more tyre distortion giving more surface area?!?!?!) I went and saw a few differant tyre shops and they all had differant theorys! so this has confused me even more!

Any ideas/help/links/annthing?!?!?!

Thanks in advance...
Kieran
(PS looks, comfort etc has nothing to do with this, purely grip!!)

Psycho_Dad · Post by **Psycho_Dad** » Fri May 30, 2008 7:02 pm

http://www.carbibles.com/tyre_bible_pg2.html
scroll down to contact patch vs grip

the only reason a bigger contact patch ever makes more grip is because the overally tyre is made of a much gripier(softer) compound , they cant do this with smaller contact surfaces(smaller tyres) because the tyre would wear out so quickly(small tyres consist of less rubber overall)

you want tyres with as little sidewall flex as possible, to keep weight as evenly distributed between the left side and right

thats why poeple uprate their suspension, to keep weight evenly distrubrited

the sidewall flex of the individual tyre is very important, depending on the model of tyre

dont believe putting 17s on your car will make it corner better, your car is only as good at cornering as its adhesion to the road surface, slapping a 205/40/17 with a weak sidewall or made of a hard compound will only make your car handle worse

remember a tyre shops job is to change and sell tires, not always completely understand them

remember weight too, for every kg you slap on your driveline its like slapping 4kg to your car(think about momentum when stopping or accelerating, and suspension dampening)

but i dont know everything, so perhaps someone else can help

PEace
Psycho_Dad

SLYDIT · Post by **SLYDIT** » Sun Jun 01, 2008 1:08 pm

205/50/15 are the best for grip IMO. mated to a 15x7 light weight wheel.
Im runninr 16" wheels and 205/45/16 and they grip well but finding a light 16/or 17" wheel is very hard for a reasonable price.

MX4000 · Post by **MX4000** » Mon Jun 02, 2008 5:25 pm

I'm using 225/45/16 that gripped far better than 205/45/15s on the track. Both with Toyo R888s. However the 225s were on an 8" rim and the 205s were on a 6.5" rim. The 205s felt very "squirmy" so I think getting enough rim width to stabilise the tyre is pretty important.

Post by **jif** » Mon Jun 02, 2008 5:48 pm

for max grip, I'd be picking Emilio's brains...
http://www.949racing.com/index.asp?Page ... ustom&ID=1

275/35 x15 on a 15x9 wheel ? whoa mama...

[Posted via external email]

mxslide · Post by **mxslide** » Tue Jun 03, 2008 9:18 pm

wow thanks for all the replys, really appreciated.
I have played around with the wheels I have for the car, (standard 14s, unknown brand 15x6.5 and SSR 17x7.5) but only on street tyres (and some pretty average ones at times!!!) now that im in the market for a decent set of tyres i want to try get the best for my money, understandably!

Ian · Post by **Ian** » Wed Jun 04, 2008 10:50 am

There is more to an MX5's handling than 'grip'.
A DOT rated race tyre such as Kumho, Toyo or Dunlop etc in 205/50 x 15 will have more grip (and be street legal = WOF), than any TR1 or similar of whatever size/profile on a 17 inch will ever provide.... but I don't know anyone who does it, for obvious reasons.

edwardyork · Post by **edwardyork** » Sun Nov 22, 2020 5:08 am

mxslide wrote: ↑
Tue Jun 03, 2008 9:18 pm
wow thanks for all the replys, really appreciated.
I have played around with the wheels at yarkoweb I have for the car, (standard 14s, unknown brand 15x6.5 and SSR 17x7.5) but only on street tyres (and some pretty average ones at times!!!) now that im in the market for a decent set of tyres i want to try get the best for my money, understandably!

Thanks a lot for this thread, with your help I was able to solve the same issue

Pokitren · Post by **Pokitren** » Tue Jan 25, 2022 2:22 am

Psycho_Dad wrote: ↑
Fri May 30, 2008 7:02 pm
http://www.carbibles.com/tyre_bible_pg2.bp
scroll down to contact patch vs grip

the only reason a bigger contact patch ever makes more grip is because the overally tyre is made of a much gripier(softer) compound , they cant do this with smaller contact surfaces(smaller tyres) because the tyre would wear out so quickly(small tyres consist of less rubber overall)

you want tyres with as little sidewall flex as possible, to keep weight as evenly distributed between the left side and right

thats why poeple uprate their suspension, to keep weight evenly distrubrited

the sidewall flex of the individual tyre is very important, depending on the model of tyre

dont believe putting 17s on your car will make it corner better, your car is only as good at cornering as its adhesion to the road surface, slapping a 205/40/17 with a weak sidewall or made of a hard compound will only make your car handle worse

remember a tyre shops job is to change and sell tires, not always completely understand them

remember weight too, for every kg you slap on your driveline its like slapping 4kg to your car(think about momentum when stopping or accelerating, and suspension dampening)

but i dont know everything, so perhaps someone else can help

PEace
Psycho_Dad

That's for sure. The better the grip, the better the turns. And 17 tires are pretty good at grip.

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