tyre size 195 or 205

[scooby-KILLER]

looking at replacing the 4 tyres on a set of slabs i have and wanted to know what size to go with?

they will be going on a mk2 gte i know both will fit but would like your guy's opinions as to what would be best before i go and order them

thanks in advance

[BlackBox]

195, I have 205's and feel they are a bit wide with clearances and grip, esp now winter is looming

[scooby-KILLER]

195, I have 205's and feel they are a bit wide with clearances and grip, esp now winter is looming

whats the issue with grip? i would have thought wider tyre more grip no?

[BlackBox]

not always, you are spreading the tire over a larger contact patch, not good in the wet

[scooby-KILLER]

but less tyre less contact less grip!

i think what your getting at is weather choice of tyre? correct tyre ie winter summer etc then more tyre contact the better the grip providing the tyre is for the condition it is being used in

i might just roll with the 195 as the car is lowwerd and dont want any rubbing issues but will hold of and see what other opinoins are put on the tabel

cheers BlackBox

[BlackBox]

No mate, you have the same grip regardless of tire size, larger contact patch = less Lbs per sq inch but the same grip cos the contact is bigger.

Smaller contact patch = more pressure per sq inch.

Biggest enemy with wider tires is water, got to move it further to get rid of it and with less pressure it gets under the tire and stays there.

[Davey j]

195 50 15s you want on slabs for the GTE. Plus your dash will read more accurate with this profile as it is closer in proportion to the original 185 60 14s.

[scooby-KILLER]

No mate, you have the same grip regardless of tire size, larger contact patch = less Lbs per sq inch but the same grip cos the contact is bigger.

Smaller contact patch = more pressure per sq inch.

Biggest enemy with wider tires is water, got to move it further to get rid of it and with less pressure it gets under the tire and stays there.

ah i need to do my home work re tyre's lol

cheers for your help mate

[Nad]

The only reason for going for a wider tyre is that they run cooler. To benefit from this, you then run a softer tyre. This is where the misnomer comes about from the motorsport world with wide tyres equalling more grip, only if they are softer. A skinny soft tyre will go off a lot faster than a wider one.

If you look at a lot of performance car tyres, you will find then running low tread wear tyres.

[Greydj]

I think there is a bit of confusion in this thread. The best site I have found for tyre info is Car Bibles : The Wheel and Tyre Bible Page 1 of 4 which explains it all.

But in particular, the contact patch size and pressure is basically the same whether the tyre is 205 or 195 in that as the tyre gets wider the contact patch gets shorter. Can't see why it should change running temperature in normal road tyres.

A narrow tyre will present a smaller frontal area which will reduce wind resistance but that may not mean any extra speed.

That site will give you the relative speedo differences for different tyre sizes/profiles.

[Nad]

I think there is a bit of confusion in this thread. The best site I have found for tyre info is Car Bibles : The Wheel and Tyre Bible Page 1 of 4 which explains it all.

But in particular, the contact patch size and pressure is basically the same whether the tyre is 205 or 195 in that as the tyre gets wider the contact patch gets shorter. Can't see why it should change running temperature in normal road tyres.

A narrow tyre will present a smaller frontal area which will reduce wind resistance but that may not mean any extra speed.

That site will give you the relative speedo differences for different tyre sizes/profiles.

It's to do with tyre distortion on the basis that wide performance tyres are lower profile. If you want the indepth tech read up on Google is prob easiest.

[scooby-KILLER]

i just went for the 195's, bought toyo t1r's or pxe maybe? not sure whats the difference if any?

cheers for all your help chaps

[GSi_Online]

Good choice. I down graded from 205's to 195's. Looks and feels loads Betta.

[Gordo]

Overall, a 195 should do you well.

Seems to be a lot of mis-information out there regarding tyre widths.
Some have realised that a narrower tyre will tend to be better under wet surface conditions, as the higher contact patch pressure is better at 'squeezing' the moisture out from under the tread blocks.
However, all else being equal and on dry surfaces, a wider tyre, with a greater contact patch, will give better grip than a narrower tyre for several reasons, due to a lower loading for the tyre contact area reducing things like the average shear force on the tyre to road interface, reduced wear, cooler running* (race tyre compounds are different from road, and have a fairly narrow operating range around 100C), etc.
I've nearly doubled tyre life by going up tyre sizes - same car, driving style, pressures, tyre brand and model.

Remember, the normal 'friction' rules don't apply - that's why you're able to use ARBs, etc, to fine tune vehicle balance.

*In summer, it's not unusual for the tar to run, so you can imagine how hot the tyres can get.

[Gordo]

NM, DP!

[astramental]

195s the 205s can hit the rear arches if its lowered or suspension is on full compression .they caught on mine with slabs with 205 50 15 tires on