Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Engineering/Technical
Register FAQ Community Arcade Calendar
Engineering/Technical Ask technical questions about cars. Do you know how a car engine works?
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools
Old 12-02-2014, 11:51 AM   #1
testname
AF Newbie
 
Join Date: Dec 2014
Location: pullman, Washington
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Any problem with using smaller overall diameter tires than just wrong speed readout?

I bought a crappy old 4x4 truck just to get around in town during the days when it's snowy/icy. 90% of the driving will be less than 35 mph and the other 10% will be less than 60 mph. I'm looking to get some inexpensive snow tires on rims, but there aren't a lot of options where I live. The vehicle currently has 235/75/r15 tires. One set of rims/tires that is for sale that will fit my vehicle is 205/70/r15. This would be about 2.5", or 9%, smaller overall outer diameter than my current tires. I don't really care if the speedometer is off by 9%. But are there other important issues I need to consider, or will these work fine? Thank you.
testname is offline   Reply With Quote
Old 12-02-2014, 02:07 PM   #2
maxwedge
A990 racer
 
Join Date: Mar 2002
Location: Chestertown, New York
Posts: 16,954
Thanks: 25
Thanked 371 Times in 365 Posts
Re: Any problem with using smaller overall diameter tires than just wrong speed readout?

Not ideal that small a tire on a fulll size? truck, but they can be used.
__________________
maxwedge is offline   Reply With Quote
Old 12-02-2014, 06:57 PM   #3
Crvett69
AF Moderator
 
Crvett69's Avatar
 
Join Date: Oct 2004
Location: Bellingham, Washington
Posts: 1,751
Thanks: 0
Thanked 73 Times in 73 Posts
Re: Any problem with using smaller overall diameter tires than just wrong speed readout?

will limit your load weight if you plan on carrying much. also need to make sure tire is wide enough at bead to fit on rim. might have to take the rims off the truck to get them mounted, most tire shops don't want to mess with different size tires for liability reasons
Crvett69 is offline   Reply With Quote
Old 12-02-2014, 06:59 PM   #4
Stealthee
Your worst nightmare
 
Stealthee's Avatar
 
Join Date: Oct 2004
Location: Smithfield, Pennsylvania
Posts: 6,058
Thanks: 40
Thanked 252 Times in 246 Posts
Re: Any problem with using smaller overall diameter tires than just wrong speed readout?

205/70/15 are passenger car tires. They are smaller than the tires on my Grand Prix.

Not only are they shorter (26.3" vs 28.9") but they are over 1" narrower.

Being they are going to be passenger car tires the load index is not going to be as much as it would be for a light truck tire. The difference is going to be as much as 500 lbs PER TIRE and could be more. This alone could cause a failure while driving.

There is no reason to put tires that small on a truck, no matter what you think the driving conditions will be.
__________________
Stealthee is offline   Reply With Quote
 
Reply

POST REPLY TO THIS THREAD

Go Back   Automotive Forums .com Car Chat > Engineering/Technical


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 05:17 PM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts