Calculate wheel diameter

DominionZA

DominionZA

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I am in negotiations with a guy at carb to trade my 19" Audi mags for his 16" Audi mags (after a smoother ride and cheaper tyre prices).

My car has a lowered suspension and with the 19" I barely clear steep driveways and large speed bumps. Not uncommon to get light scraping sounds if I approach either of these too quickly (normally).

We are in the final stages of our negotiations and I suddenly remembered the lowered suspension so went online to find a wheel dimension tool to work out the differences in overall wheel sizes. I found this : http://www.csgnetwork.com/tiresizescalc.html

The mags I want to put on are 16" with a 205/55/16 tyre profile.
The mags I have are 19" with a 255/35/19 profile.

This calculator says my overall wheel dimension will be ~2" smaller which is rather significant on an already low car.

What do you guys make of this? I am a bit concerned, but not know much about all this stuff have decided to turn to the community for thoughts.
 
This sounds like a very bad idea.
What are the stock tyres on your car?
 
The engineers at the factory go to endless lengths to get the correct wheel size, related to gearing, road holding, ground clearance, etc - why on earth mess with it? :confused:
 
Fazda said:
The engineers at the factory go to endless lengths to get the correct wheel size, related to gearing, road holding, ground clearance, etc - why on earth mess with it? :confused:
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Well you can purchase the A6 with 16" wheels, so forgive me for assuming I could just stick on a set of 16" wheels and be done with it. I did state I am rather ignorant in this field.
 
Mike Smit said:
Well you can purchase the A6 with 16" wheels, so forgive me for assuming I could just stick on a set of 16" wheels and be done with it. I did state I am rather ignorant in this field.
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It sounds like a bad idea all around.

2" difference will make the car a very different beast, and not in a good way.
 
Dolby said:
Why not 17 or 18?
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I would have preferred that to be honest. I put up an ad at Carb and this offer was the only decent one that came through. I would have preferred 17".

ToxicBunny said:
It sounds like a bad idea all around.

2" difference will make the car a very different beast, and not in a good way.
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That is what made me halt in my tracks and come post here.

Thinking I should just stick with what I got. Too many negatives here and it is making me think hard.
Besides - she looks so freaking sick with 19" low profiles. Gonna be a hard adjustment that.
 
Mike Smit said:
Well you can purchase the A6 with 16" wheels, so forgive me for assuming I could just stick on a set of 16" wheels and be done with it. I did state I am rather ignorant in this field.
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This might also depend on the exact model, the slowest will most likely have smaller brakes fitted.

If you're already scraping over bumps then a 2" reduction in diameter(1" lower ride height) seems like a bad idea, unless you go for even higher profile tyres. Which might be an even worse idea.
 
KhoisanX said:
This might also depend on the exact model, the slowest will most likely have smaller brakes fitted.

If you're already scraping over bumps then a 2" reduction in diameter(1" lower ride height) seems like a bad idea, unless you go for even higher profile tyres. Which might be an even worse idea.
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I worked out that 205/65/16 profiles will give me the same wheel diameter as what I have now - but yuck. OMG. That would look so ugly!

So I reckon we can all agree it is a bad idea. The thread is kind of speaking for its-self :)
 
Mike Smit said:
I worked out that 205/65/16 profiles will give me the same wheel diameter as what I have now - but yuck. OMG. That would look so ugly!

So I reckon we can all agree it is a bad idea. The thread is kind of speaking for its-self :)
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Don't worry, it's a Audi, you can't really make it look any worse ... :p
 
Going from 255 to 205? That is narrow!
Why not look at 255/45/16? that should give you 0.3" higher.
But you would really need to make sure the new 16" rims will clear.
Spacers is around R500 each :(
 
Changing width from 255 to 205 is probably a ridiculous idea as well.
 
wetkit said:
Going from 255 to 205? That is narrow!
Why not look at 255/45/16? that should give you 0.3" higher.
But you would really need to make sure the new 16" rims will clear.
Spacers is around R500 each :(
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Spacers are a bad idea, they put extra strain on your hubs and drive shafts.

If he goes for 245/45/16 he needs to make sure that the rims will take them
 
205 from 255?
You will feel a difference in your drive and it won't be good. If you crash I don't think your insurance will pay out.
Also it won't fit, the offset would be 55? You probably need spacers.
 
The whole idea is ridiculous.

You guys just saved me from myself. I have pulled out of the deal! THANK-YOU MyBB forumites - once again!
 
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