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-   -   Stock 17" as spare for 20's (http://www.jeepgarage.org/f156/stock-17-as-spare-for-20s-64403.html)

2014 LAREDO 08-20-2013 09:37 PM

Stock 17" as spare for 20's
 
If I had to, would it be possible to use my stock 17" spare to replace one of my 20's without messing with the drivetrain?

Stocks are 245/70/17....31" diameter
20's are 265/50/20.......30" diameter

I know the diameter can be a little off but not sure how much. :confused:

2014 LAREDO 08-21-2013 11:40 AM

Re: Stock 17" as spare for 20's
 
bump

Relwarc 08-21-2013 11:45 AM

The general rule I've read is no greater than a 3% difference. But that's front to rear, not sure about just one wheel.

Sent from my DROID RAZR using Tapatalk 2

JeepGCOverland 08-21-2013 12:23 PM

Re: Stock 17" as spare for 20's
 
Actually, there is only a .1 inch difference between the diameters, meaning a .2% difference in circumference. My guess is that you could run a 17 inch spare without any problems for a period of time.

kkreit01 08-21-2013 12:41 PM

Re: Stock 17" as spare for 20's
 
You are fine, but your calculations are incorrect:

245/70R17 = 30.50 in
265/50R20 = 30.43 in

If it were truly an inch difference, I wouldn't recommend it.

2014 LAREDO 08-21-2013 02:57 PM

Re: Stock 17" as spare for 20's
 
Quote:

Originally Posted by kkreit01 (Post 879956)
You are fine, but your calculations are incorrect:

245/70R17 = 30.50 in
265/50R20 = 30.43 in

If it were truly an inch difference, I wouldn't recommend it.

Hmmm.........I used this site to get those numbers..........

Calculate Tire Diameter

How did you get your numbers?

Thanks to you and the others that have responded. :thumbsup:

yocubed 08-23-2013 09:36 AM

Re: Stock 17" as spare for 20's
 
Quote:

Originally Posted by 2014 LAREDO (Post 880026)
Hmmm.........I used this site to get those numbers..........

Calculate Tire Diameter

How did you get your numbers?

Thanks to you and the others that have responded. :thumbsup:

that site does some serious rounding. If you actually calculate out the diameter using the same formula listed on that site here's what you get
245/70R17 = 30.504 which the site reports as 31
265/50R20 = 30.433 which is reported as 30 on the site

so the actual difference is minimal 0.232% to be precise

2014 LAREDO 08-23-2013 12:38 PM

Re: Stock 17" as spare for 20's
 
Quote:

Originally Posted by yocubed (Post 881030)
that site does some serious rounding. If you actually calculate out the diameter using the same formula listed on that site here's what you get
245/70R17 = 30.504 which the site reports as 31
265/50R20 = 30.433 which is reported as 30 on the site

so the actual difference is minimal 0.232% to be precise

Thank you sir :thumbsup:

Jeep_addicted 09-04-2013 08:22 AM

Re: Stock 17" as spare for 20's
 
The only thing that would stop you from using the 17" as a spare would be if you had the HD (BR6) brake package. On the front axle the minimum wheel size would be 18" to clear the brakes.

You have a laredo so this is not an issue but for the benefit of someone else considering doing this. It would be a factor they would have to determine.


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