Tire Size vs Speedo??
#1
Registered!!
Thread Starter
Join Date: Mar 2009
Location: Vermont
Age: 36
Posts: 97
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Tire Size vs Speedo??
I still have stock 185 on steelies.
I've been looking to upgrade, but wont going so something like 215 make the speedometer inaccurate?
What do i need to look out for? I dont want a bad speed reading...
Noob to rims, sorry. Search brought up nothing.
I've been looking to upgrade, but wont going so something like 215 make the speedometer inaccurate?
What do i need to look out for? I dont want a bad speed reading...
Noob to rims, sorry. Search brought up nothing.
#2
Registered!!
Join Date: Jul 2009
Location: PARIS ONTARIO CANADA!
Age: 37
Posts: 73
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Tire Size vs Speedo??
i got 17s with 205/45/R17s and they dont effect my speedo but ive heard over 18s will effect your speedometer with a 6th gen. not sure about the 7th gens. prolly 18s would be fine lots of people run them.
#3
Whachya lookin at?
iTrader: (1)
Join Date: May 2009
Location: Canada
Age: 38
Posts: 6,388
Likes: 0
Received 11 Likes
on
7 Posts
Rep Power: 289 Re: Tire Size vs Speedo??
I'm not 100% sure, but you adjust for larger wheel size by buying smaller tires.
Example : 185/65/14
The first number is just tire width, so it will not affect your speedo at all.
The second number is tire heigth, this one has an effect.
The third number is wheel size in inches.
That being said, if you move from 14 inch steelies to 17 inch rims you would adjust accordingly.
185/65/14 < 14 inch steelies
225/35/17 < 17 inch rims.
These would be your tire sizes, see how you adjusted for wheel size by reducing the height of your tires, for every 1 inch you reduce 10 mills off your tire height.
Now to the problem, you can't always find the right sized tires height wise to suit your rims, and you kinda have to deal with that by buying whatever fits that particular rim. This is when you can screw your speedo up!
If someone can confirm this as I'm not 100% sure.
Example : 185/65/14
The first number is just tire width, so it will not affect your speedo at all.
The second number is tire heigth, this one has an effect.
The third number is wheel size in inches.
That being said, if you move from 14 inch steelies to 17 inch rims you would adjust accordingly.
185/65/14 < 14 inch steelies
225/35/17 < 17 inch rims.
These would be your tire sizes, see how you adjusted for wheel size by reducing the height of your tires, for every 1 inch you reduce 10 mills off your tire height.
Now to the problem, you can't always find the right sized tires height wise to suit your rims, and you kinda have to deal with that by buying whatever fits that particular rim. This is when you can screw your speedo up!
If someone can confirm this as I'm not 100% sure.
#4
Registered!!
Join Date: Jun 2009
Location: Miami, FL/Charlotte NC
Posts: 43
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Tire Size vs Speedo??
yeah that's pretty much correct. The second number (e.g. the 65 in 185/65/14) is actually a ratio of the height to the width, not just the height in millimeters so it's a little more algebra to calculate the actual height of the wheel/tire combination. However, if you don't want to sit down and work this out, there are plenty of calculators on the internet that will tell you the total height of a certain wheel size with a certain tire size. Like tbohar said, only height affects the speedo reading, just get shorter tires so the total height will be the same as stock.
#5
Registered!!
Join Date: Apr 2008
Location: Calgary, Alberta
Age: 40
Posts: 954
Likes: 0
Received 1 Like
on
1 Post
Rep Power: 206 Re: Tire Size vs Speedo??
tbohar: not sure if you know, but the width does actually matter. the height (35,45,55 etc) are all a percentage of the width, so a 225/45 and a 205/45 will have a different height. the 225/45 will be higher (45% of 225 mm) than the 205/45 (45% of 205 mm).
anyway, if you want to go with 215, you should use 215/45/r17. the overall diameter of a 215/45/17 is within only a couple of mm of stock 185/65/r15. it will keep everything on your car (height, wheel well gaps) basically the same as stock.
anyway, if you want to go with 215, you should use 215/45/r17. the overall diameter of a 215/45/17 is within only a couple of mm of stock 185/65/r15. it will keep everything on your car (height, wheel well gaps) basically the same as stock.
#6
Whachya lookin at?
iTrader: (1)
Join Date: May 2009
Location: Canada
Age: 38
Posts: 6,388
Likes: 0
Received 11 Likes
on
7 Posts
Rep Power: 289 Re: Tire Size vs Speedo??
Thanks for correcting me guys. I just made an educated guess with no research for a change. Last time I'll do that! Go with what these guys say and maybe use a calculator to figure out the best tire for you!
#7
Banished to the Depths of Rice.
iTrader: (3)
Join Date: Jun 2005
Location: SoCal 714/909/626
Posts: 9,196
Likes: 0
Received 1 Like
on
1 Post
Rep Power: 328 Re: Tire Size vs Speedo??
also, the rim width + width of the tire needs to be taken into consideration.
for example, a 17x6 rim will fit a 205/40/17 with stock ratio..
however, put the same 205/40/17 tire on a rim that is 17x7 and you will have a smaller sidewall because the tire will be doing this
/-----\ (because the rim width streches it a bit more
vs
|-----| which is what stock looks like.
#8
Banished to the Depths of Rice.
iTrader: (3)
Join Date: Jun 2005
Location: SoCal 714/909/626
Posts: 9,196
Likes: 0
Received 1 Like
on
1 Post
Rep Power: 328 Re: Tire Size vs Speedo??
use http://www.miata.net/garage/tirecalc.html
and calculate what tire size you can get that wont effect the speedo too much.
that tire size calculator doesnt take into account the rim width on tire. it assumes all the tires are |-----|
stock civic tire size are:
2001-2003 LX: 185/70R14
2001-2003 EX: 185/65R15
2004-2005 EX/LX: 195/60/15 (SE is the same i believe)
////////edit
even if you have OEM rims/tires your speedo will ALWAYS be 5% (+/- a few) due to the pressure of ur tires, cold or warm
and calculate what tire size you can get that wont effect the speedo too much.
that tire size calculator doesnt take into account the rim width on tire. it assumes all the tires are |-----|
stock civic tire size are:
2001-2003 LX: 185/70R14
2001-2003 EX: 185/65R15
2004-2005 EX/LX: 195/60/15 (SE is the same i believe)
////////edit
even if you have OEM rims/tires your speedo will ALWAYS be 5% (+/- a few) due to the pressure of ur tires, cold or warm
Last edited by sl33pyriceboi; 07-26-2009 at 01:15 AM.
Thread
Thread Starter
Honda Civic Forum
Replies
Last Post
muttleytm
6th Generation Civic 1996 - 2000
1
07-08-2015 04:13 PM
BootyDo
Wheels, Tires & Brakes Modifications
2
07-07-2015 06:06 AM
Causemo
Mechanical Problems/Vehicle Issues and Fix-it Forum
1
07-05-2015 06:42 AM