18" vs 20" rim size

18" vs 20" rim size

Author
Discussion

trumpton7291

Original Poster:

200 posts

10 months

Thursday 1st February
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Sure 20" rims look nice but are there any other advantages? Roads near me are full of potholes so I'd be a bit concerned of damaging them like the below:



Anyone gone 20" and regretted it? (I mean if you actually use the car, rather than just keeping it in the garage and cleaning it... hehe

I saw in the Tesla forum (don't ask) the smaller wheel sizes seem to have quite a significant improvement in range, so I did wonder if 18"s had better economy.

Super Sonic

7,299 posts

61 months

Thursday 1st February
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You can fit bigger brakes with 20" than you can with 18"

TheOctaneAddict

875 posts

54 months

Thursday 1st February
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Ran both on my Cayman, 18s give a slightly better ride but the 20s look so much better and I think they are slightly lighter.

I have switched back to the 20s recently and I am much more careful of holes and big ruts.

Probably going to be shifting the 18s on now as the car just doesn't look right with them.

Super Sonic

7,299 posts

61 months

Thursday 1st February
quotequote all
TheOctaneAddict said:
the 20s look so much better and I think they are slightly lighter.

Given an identical wheel design in 18" & 20", the 18" will weigh less, because it is made with less metal.

SkinnyPete

1,488 posts

156 months

Thursday 1st February
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Super Sonic said:
Given an identical wheel design in 18" & 20", the 18" will weigh less, because it is made with less metal.
I think you’ll find that might not be the case.

Often rolling radius is maintained between wheel sizes and tyres with a higher profile negate any weight saving from the smaller alloy.

That’s been my experience when I’ve weighed my Cayman summer wheels/winter wheels.

Super Sonic

7,299 posts

61 months

Thursday 1st February
quotequote all
SkinnyPete said:
I think you’ll find that might not be the case.

Often rolling radius is maintained between wheel sizes and tyres with a higher profile negate any weight saving from the smaller alloy.

That’s been my experience when I’ve weighed my Cayman summer wheels/winter wheels.
I was comparing the weight of the wheels, not the wheels with tyres. Bigger wheels are heavier. A smaller wheel with more added weight may weigh the same as a bigger wheel with less added weight, it may even weigh more, but that's not what I said.

LunarOne

5,761 posts

144 months

Thursday 1st February
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Super Sonic said:
SkinnyPete said:
I think you’ll find that might not be the case.

Often rolling radius is maintained between wheel sizes and tyres with a higher profile negate any weight saving from the smaller alloy.

That’s been my experience when I’ve weighed my Cayman summer wheels/winter wheels.
I was comparing the weight of the wheels, not the wheels with tyres. Bigger wheels are heavier. A smaller wheel with more added weight may weigh the same as a bigger wheel with less added weight, it may even weigh more, but that's not what I said.
What's the point in comparing wheels without tyres? You can't drive your car on wheels without tyres, so there's no reason to compare weights of wheels without tyres unless you're comparing how much metal you get for a particular price.

Super Sonic

7,299 posts

61 months

Thursday 1st February
quotequote all
LunarOne said:
What's the point in comparing wheels without tyres? You can't drive your car on wheels without tyres, so there's no reason to compare weights of wheels without tyres unless you're comparing how much metal you get for a particular price.
Doesn't make me wrong though, does it?
Same wheels, same profile/ width tyres in two different sizes, the smaller one will be lighter.

Ed.Neumann

608 posts

15 months

Thursday 1st February
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What did the 19" do so wrong?

Super Sonic

7,299 posts

61 months

Thursday 1st February
quotequote all
Ed.Neumann said:
What did the 19" do so wrong?
They're just odd!

Ed.Neumann

608 posts

15 months

Thursday 1st February
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Super Sonic said:
They're just odd!
biggrin

scrounger73

299 posts

165 months

Friday 2nd February
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You can fit 18's over the big brakes on the GTS 4.0 as I have 18s as my winter set.

Sadly I think it's just the poor condition of our roads that are to blame however there may be a compen case with your local council if they fail to maintain a road which then leads to damage of a vehicle.

Alex Z

1,512 posts

83 months

Friday 2nd February
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LunarOne said:
What's the point in comparing wheels without tyres? You can't drive your car on wheels without tyres,
The chap I saw on Motorway Cops was giving it a good try.

Ed.Neumann

608 posts

15 months

Friday 2nd February
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The thing with going with 18's over 20's is you can run firmer damping, especially on the rear, which will give you so much nicer, sharper steering feel and turn in. It sharpens everything up and with the 18's means it is not shaking your teeth out.




mattknight1984

158 posts

122 months

Friday 2nd February
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Mine came with 20s - I think the 18s look a bit small/daft, especially on the 981. I don't find the ride too bad, but I don't have PASM either.

981Boxess

11,529 posts

265 months

Friday 2nd February
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I have both 18" and 20" wheels with summer tyres, given the state of our roads the 18" do a far better job overall IMO.

When I go abroad I put the 20" back on as they seem to have roads that are fit for purpose over there for some reason.