dilema with using 18 in alloys or 17 in alloys?

[rajuk]

Dear fellow forum members

i was planning on selling my 17in wheels but two minded now.


Ihave a porsche Boxster 2.7 2002 car with 7500 miles.

I bought the car on 28/8/03 from Porsche swindon.

some of you may not know but know i skidded the same day on the way home and mounted a Kerb.


Currently i have the sport Classic 1 TYPE alloy wheels.

These are 17 in wheels with P zero rosso n3 tyres

According to Porsche when car was serviced in July 2003 the wheels all had 6mm tyre tread. That was at 6000 miles


Sadly i skidded on diesel and mounted a kerbon the same day I bought the car and damaged the Rear left alloy and damaged both front left and rear left tyre.

The front alloy was replaced with a new one and two new pirelli P zero rossos were put on.

Hence now two alloy wheels have 6mm tread the other are month old.

They are all ok and all balance well.


I have bought some new 18 in Sport Classic two wheels with Continental tyres.

However the Family are objecting to them being put on.


The reason when i crashed the car and it was recovered the RAC person who brought it home on a Trailer said that 18 in alloys are more slippery in the wet than 17 in.


He told my family that with 18in wheels the weight of a car is spread over a greater area, hence there is less grip in the wet. he said 17 in wheels are better in the wet and 18 in the dry.


I want to put on the 18 in wheels, but getting a lot of pressure from family etc NOT to.


What is your take?

the 18 in wheels have continental tyres as i heard they better than pirelli p zeros.


Should i keep the 18 in alloys and flog my 17 in wheels



or keep my 17 in alloys and sell the 18 in alloys which are new?


either way one set will be available on here and later on ebay


Raj

[ew_topcat]

If the tyres are the same width then there is the same amount of rubber on the road, regardless of the height of the wheel. Different tyre specs can make a lot of difference eg: compound and pattern.

[domster]

The main problem is normally sidewall stiffness. The 17s may run a taller tyre, with more progressive breakway than a low profile 18.

This also means ride quality may suffer slightly.

If the 18s are a larger width then they will exhibit the symptoms described of more grip in dry, more aquaplaning in the wet, more tramlining and potentially a snappier breakaway when they let go.

[oldtimer]

don't know about boxster but on a 996 the 17 inch wheel widths are 7J front and 9J rear, the 18 inch wheel widths are 7.5J front and 10J rear. The J number represents the width in inches of the tyre. So yes the bigger wheels put a larger rubber area on the road, in the dry thats more grip, in the wet you have to take into account the tyre tread and compound. If you go on diesel again I dont think either wheel size will make a difference. If you are just driving around on the roads and obeying speed limits you wont be any faster with either, the advantage of 17 inch is cheaper tyres and a softer ride over bumps, the advantage of 18 inch is that they look cool.
If the family are paying the bills you got to go with them....