Mismatching tires

[DoriftoTSi]

I'm able to get to get some new tires and rims for pretty cheap, but the problem is, 2 tires are wider and have a different tread than the other two. Would my differential get messed up if i were to put these on. They are the same size other than it's width.

 

[Defiant]

If the outside diameters are the same, you may get away with it. I don't know if the different growth rates will matter.

I'd not do it, even for free tires.

 

[UCSLugRacerX]

I'm able to get to get some new tires and rims for pretty cheap, but the problem is, 2 tires are wider and have a different tread than the other two. Would my differential get messed up if i were to put these on. They are the same size other than it's width.

If the wider/sticker tires are on the rear this will give your car the tendancy to power-on understeer. If installed on the front, it will cause lift-throttle oversteer.

Also, with mis-matching rubber compounds and tire widths, you change the tire slip angles and tire traction limits.
Mismatching tires is not necessarily a bad thing, that is--if the difference in each tires' slip angle is not too great.

IMO, put the wider tires on the end that is breaking traction first, or replace them with the tires which are being overworked.
Also, if you put them in the rear, drag racing from a dead-stop will improve. Placing them in the front (causing lift throttle oversteer), will make the car rotate and turn easier.
As long as a all 4 tires have equal circumferance, you center differential will be unaffected.