I've been using this forum so much lately, I figured a real question was in order.

 

So I know if you use 4wd you need to replace all four, but I just bought a 1986 Leone 3door--i'll have some pics later, gotta clean it up a bit--and it had one tire mismatched. The car is currently only running in "rear wheel drive" because the front wheel hub has no splines left, but the tranny is fine i believe.

 

With that being said, once I fix the hub I won't be able to run 4wd without buying 4 new tires. I'm heading on a 2,000 mile road trip in like 3 weeks and am wondering if using FWD eliminates the risks involved with having a mismatched tire?

They all do not have to have exactly the same wear. The steering may just pull to one way or the other. The open slip differential takes care of any differential tire wear in the rear.

Interesting, I guess I may have been reading about newer generation AWD cars. That's good to know.

For a living, I do in-out shipping, and order/sell motorcycle parts, apparel and accessories.
 

Having a motorcycle with matching tires, especially sporty bikes, is rather important.

Sport bike tires need to heat at the same ratio, possess the same amount of lean angle, have the same contour from side to top and... This and that.

 

In terms of cars, regardless if it's FWD, RWD, AWD, 4WD - The tires aren't nearly as crucial in terms of matching.

That is at least, not for the intented purposes of your Leone.

 

Each tire is 25% of the vehicle's connection to the ground.

 

If it was some slammed WRX, it would mean something more.

 

What's more important, rather than the fact that there's an oddball....

Is that the demensions are the same.

 

180/55/17 - example

(Width/AspectRatio/WheelSize)

 

If that's even across the board, you're in the clear.

Thanks for the reply. I was mostly concerned because I read stuff about it possibly tweaking the driveline or other things because even if all of the tires are 175/70/13, they'll have different circumferences if they've been worn uneven or are different brands of tires. I'm gathering that this isn't a problem with older subaru's because they don't have LSD in the back?

You just need to have a matched set up front.

 

The rears can be different just do not use the 4wd on pavement.

if your going to mix tires, check the manufacturer for the actual diameter.  the 175/80r14 type of designation is just ballpark.  4wd isnt as critical as Awd but id still do at least 2 at a time.  keep the axles the same, meaning keep matching tires on the front and on the back.

You just need to have a matched set up front.

 

The rears can be different just do not use the 4wd on pavement.

 

Roger that. Thanks for the help everyone.

run FWD or RWD all day long, i've done it a bunch of times.  just don't be dumb and these systems are rather robust.