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Technical Tyre sizes, how wide can I go?

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Technical Tyre sizes, how wide can I go?

hastingsmum

hastingsmum

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I had 195/60/15s all around, then 195s on the rear and 205s on the front and now 205s all around. It drives sooooo much better with the wider tyres all around, but could I fit even wider ones to the front?

I found a table: "formula (15"x24.5)+((width*depth%)x2)

similarity between 185/65/15 and 205/60/15 99.10%

similarity between 195/60/15 and 215/55/15 99.59%"

Does this make sense to anyone? Can I have 215s on the front you think?
 
Those comparisons you posted are for the 'Rolling Circumference' of the Wheel/Tyre sizes, so if you're going up a Wheel size (e.g. 15" to 16"), you can choose a Tyre that keeps the overall gearing the same, otherwise your speedo can over/under-read, and you can have Tyre interference with parts of the Bodywork, Chassis, Suspension etc.

The Tyre 'Aspect Ratio' (the number after the Width) is the Tyre's 'height' from Rim to Tread, expressed as a percentage of the Width.
E.g. A 195/60 Tyre will have a height of 117mm (60 % of 195mm).
A 205/60 will be 123mm
A 215/60 would be 129mm
As you go up in width, you need to go down in Ratio, to keep the overall size (Diameter/Circumference) the same, or as close as possible.
So if you went to a 215 instead of the 195, to keep the gearing the same, you'd have to choose a 215/55, which would give you 118mm, close enough not to matter.

The standard width (at least on my '02 115) is 6.5", so you can theoretically go up to 215 as a maximum, but 195 (standard fitment) or 205 is recommended.

Rim/Tyre match chart

I have 205s on my 6.5 x 15 Coupe Wheels.
 
Last edited:
BikeDoc said:
Those comparisons you posted are for the 'Rolling Circumference' of the Wheel/Tyre sizes, so if you're going up a Wheel size (e.g. 15" to 16"), you can choose a Tyre that keeps the overall gearing the same, otherwise your speedo can over/under-read, and you can have Tyre interference with parts of the Bodywork, Chassis, Suspension etc.

The Tyre 'Aspect Ratio' (the number after the Width) is the Tyre's 'height' from Rim to Tread, expressed as a percentage of the Width.
E.g. A 195/60 Tyre will have a height of 117mm (60 % of 195mm).
A 205/60 will be 123mm
A 215/60 would be 129mm
As you go up in width, you need to go down in Ratio, to keep the overall size (Diameter/Circumference) the same, or as close as possible.
So if you went to a 215 instead of the 195, to keep the gearing the same, you'd have to choose a 215/55, which would give you 118mm, close enough not to matter.

The standard width (at least on my '02 115) is 6.5", so you can theoretically go up to 215 as a maximum, but 195 (standard fitment) or 205 is recommended.

Rim/Tyre match chart

I have 205s on my 6.5 x 15 Coupe Wheels.
Click to expand...

Thank you! Will give it a go when I need new ones (they are almost new all round now)
 
Re: Tyre sizes?

BikeDoc said:
That's why I went for the 205s, much more choice at cheapo (<£60) prices (y)
Click to expand...
So will have to stick with them then, I say like it's the end of the world:rolleyes: I love how it handles with them compared to the 195s. And can you believe I actually asked a young lad in a tyre place how wide I could go and he checked and told me I needed to go to 185s:eek: because that was the manufacturer recommendation and that is best for my car:bang:
 
Thing is, because of the wide body on the Multipla, even if you stuck 250s on it it'd still remind me of an old Commer Van . . .
2007_0506Image0008-1.jpg
 
Unless of course you go down for the 17's route, if you are looking for better handling. Try and stick to Fiat or Alfa 17" alloys.
 
Last edited:
Re: Tyre sizes?

hastingsmum said:
... And can you believe I actually asked a young lad in a tyre place how wide I could go and he checked and told me I needed to go to 185s:eek: because that was the manufacturer recommendation and that is best for my car:bang:
Click to expand...

Whatever was that “young lad” thinking about - he needs to get his thinking straight.
The tyre shop owner may not be pleased about the missed golden opportunity of re-inforcing & agreeing your obvious need for 4x 245/35R15 tyres … ka-ching!

Jesting aside. The lad was perhaps too keen to disclose his training course knowledge re `within spec’ & `approved’ combinations.

Check-out a rim conversion chart
e.g. Bridgestone Pattern Digest.

291202Z
 
hastingsmum said:
(y)
What could I have on 17s? Might be worth looking at.....:cool:
Click to expand...

I have the factory option 17" wheels on mine. They are a 7J x 17 size. Standard tyres are 205/45/88V, no doubt could go to 215 or 225 where allowed, but its not the width, its how different the multipla handles on 17's compared to the standard 15's.

My turn in/out is very sharp. Tracking is set differently and they fill the wheel arch better. From a viewpoint, the multipla sits on the road better on 17's than 15's in my opinion. Good rubber also makes a good point also.

As to ride, the 15's are soft and comfortable, where as the 17's are not hard ride by any means, yes you can feel uneveness in a road / pot hole comapared to a standard wheel, but i prefer it as you get more feedback from the steering, thus the steering is not lifeless and numb.
 
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