Hi

Got my MOT next want to get some alloys to be fitted when car goes for service.

So what size alloy is safe for my GP 1.2 Active 8v? Handbook states 6j X 15"- et43 but am sure I can push the envelope a bit. Read horror stories gearbox failing with 17s for alloys.

https://www.fiatforum.com/grande-punto/244126-maximum-size-tyre-1-2-17-alloys.html

https://www.fiatforum.com/grande-punto/216296-17-wheels-grande-punto-2.html

I am a bit heavy footed when it comes to motorway and country road driving which has become a hobby during the weekend. Also would love grip so tyre size recommendations are welcome.

Dodza said:

Hi

Got my MOT next want to get some alloys to be fitted when car goes for service.

So what size alloy is safe for my GP 1.2 Active 8v? Handbook states 6j X 15"- et43 but am sure I can push the envelope a bit. Read horror stories gearbox failing with 17s for alloys.

https://www.fiatforum.com/grande-punto/244126-maximum-size-tyre-1-2-17-alloys.html

https://www.fiatforum.com/grande-punto/216296-17-wheels-grande-punto-2.html

I am a bit heavy footed when it comes to motorway and country road driving which has become a hobby during the weekend. Also would love grip so tyre size recommendations are welcome.

Click to expand...

Hi Dodza, don't just go on my word but some alloys from the dynamic would probably be okay if you wanted to keep it stock fiat, however I have heard the gearboxes on the 1.2 operate at full capacity with standard 15 inch wheels. In the end if you go beyond the manufacturer guidelines then you do risk something going bang so do so at your own risk! Im sure someone else will be along with some more advice soon

Not only what LordFox has said, but in a 1.2 it will affect the car's performance for the worst noticeably so, both in terms of having to accelerate and decelerate a bigger mass, but also in suspension and handling due to increased un-sprung weight.


Both cases are bad. In a bigger car with more power and torque the first two effects are perceivably less noticeable, but they are there non the less, particularly deceleration, and of course suspension and handling.


I fitted bigger tyres 205/50/R15 on my 1.3GP on the standard alloys and the extra weight is definitely noticeable on acceleration, but also in MPG. In my case the size was an error on my part, but I wanted all year round tyres so kept them despite the performance hit.


If you are going to buy alloys, its only worthwhile if you can guarantee to replace with something lighter, rather than heavier.


Humour

Thanks guys.
So weight added to car doesnt affect perf that much except alloys? ?Doesn't add up(Y u do dis Fiat). So even of I add more tread to give the car grip it wont matter I will take a performance hit?

Also anyone know weight 15" steelies with the tire

What about these
Inovit ST VI 6.5x16" Alloy Wheels finished in Gunmetal
http://www.alloywheelworld.co.uk/in...wheels-finished-in-gunmetal.html#.Vcp_DiZViko

Dodza said:

Thanks guys.
So weight added to car doesnt affect perf that much except alloys? ��Doesn't add up(Y u do dis Fiat). So even of I add more tread to give the car grip it wont matter I will take a performance hit?

Click to expand...

There you go fella, don't believe me, read up instead http://www.caranddriver.com/features/effects-of-upsized-wheels-and-tires-tested the effect on a small engine car will be bigger is what I'm saying.


Adding tread doesn't necessarily provide extra grip. Grip comes from the tyre compound, the tyre tread is a balance between providing a bigger tyre contact patch to the ground (more grip) vs. water dispersal channels/grooves when wet to minimize aquaplaning to ensure the contact patch to the ground is maintained when wet. Slick tyres don't have tread and provide the most amount of grip when dry, but when wet they are a disaster, hence why racing wet tyres have grooves in them similarly to road tyres. You need to do more reading I feel.

The ST6 are nice wheels, had them on my Alfa 155 many moons ago. Held up to pot holes well too.


Humour

Thx for the link. Sorted no alloys till next car.