So I've got 175/70/R13's in the rear and 185/70/R13's up front.

 

I'm wondering how this will affect 4WD in the snow, because I'm probably going to Mt.Baker tomorrow (and they are getting snow!).

diameter matters, width doesn't - you have the same diameter tires, just different width

 

may affect handeling a bit (sideways slide), but not much - you shouldn't bind the 4WD

I would only add that on dry pavement even if the diameters are the same, you shouldn't use 4WD because the amount of wear may differ and in the long run hurt your transfer case, but if you're only using 4wd in snow, its a non-event. I'm certainly guilty with the 88GL.

 

 

Jordan

So I've got 175/70/R13's in the rear and 185/70/R13's up front.

 

I'm wondering how this will affect 4WD in the snow, because I'm probably going to Mt.Baker tomorrow (and they are getting snow!).

 

These tires are NOT the same diameter!!!! You WILL have handling issues in 4WD.

Actually, since the profile is a derivative of the tire width (it's a ratio of width to height), the difference in diameter between a 185/70/13 and a 175/70/13 is about 1/2 inch. On dry pavement, you could experience some binding in 4wd. You should be OK in loose snow or on ice. As Hodaka said, you could experience handling issues.

diameter matters, width doesn't - you have the same diameter tires, just different width

 

may affect handeling a bit (sideways slide), but not much - you shouldn't bind the 4WD

 

But the "70" is a percentage of the tires width right? So the percentage can be the same but if width changes it will affect the ratio thus affecting the height...

 

Or am I completely off base here.

 

Just by looking at the tires, the rears are clearly smaller than the fronts (by maybe an inch or more).

Actually, since the profile is a derivative of the tire width (it's a ratio of width to height), the difference in diameter between a 185/70/13 and a 175/70/13 is about 1/2 inch. On dry pavement, you could experience some binding in 4wd. You should be OK in loose snow or on ice. As Hodaka said, you could experience handling issues.

 

Didn't mean to be redundant, I was replying just as you submitted your reply.

 

So, the bottom line is, it will (slash) may affect handling, on the snow I should be okay as far as transfer case damage (or whatever may occur).

 

I guess what I want to hear is, "Don't let it stop you from enjoying some freshies tomorrow!".

These tires are NOT the same diameter!!!! You WILL have handling issues in 4WD.

OK I may be wrong, but as I recall -

175/185 refers to "section width" measured across the inside of the tire

70 refers to "section height" measured on the inside of the tire

13 refers to the diameter of the tire

 

these are metric tires, so they do not use the SAE system of measurement,

 

the cars came in as little as 165 section width, and all used the 70R13 diameter tire - therefore all rims are interchangeable (exception being some don't have enough space for brakes)

 

as much as I have swapped on my car, I should know what does/doesn't work - and I have not had issues using 4WD with most any combination of tires

 

even if the tires were slightly different diameters, if they are being used on snow it wouldn't matter because there would be slippage - if an LSD was involved, there would be problems

 

I would only add that on dry pavement even if the diameters are the same, you shouldn't use 4WD because the amount of wear may differ and in the long run hurt your transfer case, but if you're only using 4wd in snow, its a non-event. I'm certainly guilty with the 88GL.

he he - ditto on that - tight turns do NOT work well in 4WD, even if there is slippage - and 4WD should ONLY be used on slippery surfaces

185 is the width of the tire in millimeters/70 is the ratio of the tire's height to its diameter/R stands for radial/13 is the rim diameter.

 

So the only thing that's the same is the diameter of the rim.

they are different heights, period, the section height is calculated as a percentage of the width: diameters are 23.2" vs. 22.6" (calculated using the tire calculater on subarubrat.com)

 

if you've got the smaller ones on the front and the bigger ones on the rear (or vice versa) you WILL have binding. it won't hurt anything on snow, but it might effect handling.

 

I had the same thing for awhile, here's what I did: put the bigger ones on one side, and the smaller ones on the other. this way you've got the same *average* size front and back. the diffs will make up for the difference, and no binding will occur at the tcase. NOTE: DO NOT DO THIS IF YOU HAVE AN LSD! it's not any worse than going around a corner, always, but an LSD will slowly build up heat, and wear quite quickly, but an open diff will just slip.

But having different-sized tires side-to-side can also cause handling problems.

I would suggest getting all four tires of the same size and rotate them on a regular basis.

 

if you go to www.tirerack.com you will find that you can get brand new tires for that rim for under $30 a peice, or snows for $60. I don't think you will be getting stuck in less than a foot of snow running those blizzark's Check out Dayton Daytona's too, if you can find them they go cheap. It's not really worth your drivetrain to run the different size tires! If you hurting for cash head to the junk yard and pick up a used set! IF you can't do any of this, resist using the 4x4 unless you absolutely need to.

 

hope this helps,

 

Fishums

I ran different size tires side to side for a few months. same sizes even, with no noticable handling issues.

using the ole' tire size calculator, the 175's are 22.6in overall diameter and the 185's are 23.2in. no matter what the diffs will be turning at different speeds which is never good. I wouldn't do it, but alot of people would! Just buy a couple tires should be cheap. just my $.02.

no matter what the diffs will be turning at different speeds which is never good.

 

uh, thats what diffs are designed to do LSDs will have a problem but open diffs can spin round and round all day long.

 

I would run with what youve got. Ive run slightly different size tires in other 4wd (locked center) vehicles in gravel and snow and the difference was barely perceptible. On pavement its not a good thing as others have said.

dont drive it like that. its gonna be dangerous as hell. I drove my car 100 miles like that one time because I blew out the two back tires and my spares were smaller. Made for one scary drive home. Because its on snow, you dont feel binding, you slide all over the ************ing place and can't control it

On www.craigslist.com you can sometimes find good snow tires for super cheap (locally). I got a set of 4 for 80 bucks in brand new condition for my car (185/70/r13).

maybe i was a little off in my wording? What I mean is if there is a difference in total height of the tires then one set of tires is going to spin at a different speed then the other set. That is rough on your drivetrain.

175/70/R13's is 22.6inch dia

185/70/R13's is 23.2inch dia

 

175/70/R13's is 97.5% of the dia size of 185/70/R13's

 

I'd say you'd have some fun slipery slides. I wouldn't use 4WD, you'd prolly have less traction then in 2WD