I want to put some new wheels on my 405 but I'm a total beginner when it comes to sizes etc.... I have a 1993 SRDT. The existing tyres say 185/65/R14.
My questions are :
1. What do each of those figures actually mean?
2. Does this mean that my wheels are also size 185/65/R14?
3. Do some dealers use other way of measuring that is 'equivalent' to 185/65/14?
4. Could i put 15's on if i wanted? Does it change the handling and how?
5. Can i put wider wheels on? and how...what would i need to change?
Thanx in advance, Neil.
Which wheels fit my 405?
Moderator: RichardW
Re: Which wheels fit my 405?
Really cant do it better than explained in the link by Steve.
I'll try with some direct replies anyway
185 = footprint width of the tyre in millimeter.
65 = height of the tyre (profile) in percentage of the footprint width, i.e. 65% of 185mm = 120.25mm (65% = 65/100)
14 = rim diameter in inches. 1 inch = 25.4mm. 14" = 355.6mm.
Now you can calculate the total diameter of your 185/16-14 tyres :
2 x tyre height + rim diameter = 2 x 120.25mm + 355.6mm = 596.1mm.
The circumference is then pi x r x 2 = pi x 596.1mm = 1872.7mm
(provided that its all new tyres, not worn down, that is)
You just need a lower profile tyre to reach the figures calculated in 1)
Handling is in general closer to a go-cart, the smaller profile tyres you get. The trade off is ride comfort, as there is no longer a large tyre pillow to swallow minor imperfections from the road.
I dont think you can get any wider than 205mm on a 405, and that will almost certainly also give you some scrubbing during spirited drive.
Remember that most tyres do some "ballooning" sidewards on the tyrewalls, which may scrub on the inner wheelarches, or the McPherson struts on front.
I'll try with some direct replies anyway
185/65/14 translates to :Neil34 wrote:1. What do each of those figures actually mean?
185 = footprint width of the tyre in millimeter.
65 = height of the tyre (profile) in percentage of the footprint width, i.e. 65% of 185mm = 120.25mm (65% = 65/100)
14 = rim diameter in inches. 1 inch = 25.4mm. 14" = 355.6mm.
Now you can calculate the total diameter of your 185/16-14 tyres :
2 x tyre height + rim diameter = 2 x 120.25mm + 355.6mm = 596.1mm.
The circumference is then pi x r x 2 = pi x 596.1mm = 1872.7mm
(provided that its all new tyres, not worn down, that is)
You can directly read off the tyre size from your tyres. That will be the big figures in the same notation as the 185/65-14 notation.Neil34 wrote:2. Does this mean that my wheels are also size 185/65/R14?
No. But they calculate a new tyre size, if you want, say, a larger alloy wheel with lower profile tyres. They always aim to to end up with the same figures as the diameter/circiumference calculated in 1), as this is the legal requirements.Neil34 wrote:3. Do some dealers use other way of measuring that is 'equivalent' to 185/65/14?
Yes, you can put 15", 16" or even 17" rims on if you want.Neil34 wrote:4. Could i put 15's on if i wanted? Does it change the handling and how?
You just need a lower profile tyre to reach the figures calculated in 1)
Handling is in general closer to a go-cart, the smaller profile tyres you get. The trade off is ride comfort, as there is no longer a large tyre pillow to swallow minor imperfections from the road.
Yes - within certain limits. It depends on how wide your wheel arches are.Neil34 wrote:5. Can i put wider wheels on? and how...what would i need to change
I dont think you can get any wider than 205mm on a 405, and that will almost certainly also give you some scrubbing during spirited drive.
Remember that most tyres do some "ballooning" sidewards on the tyrewalls, which may scrub on the inner wheelarches, or the McPherson struts on front.
Anders (DK) - '90 BX16Image