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Question re:same brand tires for 4WD vehicles???


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16 replies to this topic

#1 bgambino

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Posted 06 December 2004 - 07:01 PM

OK
I've read stuff that it is very important to use same type tires on all 4's(as well as tread depth being consistant all around)....otherwise, stress on the differential...
I have a 91 loyale automatic 4WD...push button 4WD
If I am in 2WD....would it matter if fronts were bald and rears were new (hypotheically)---no stress on diff?....Wouldn't there be stress ONLY if I engage the 4WD???

I have also heard that you should have the same brand on all 4's because diameters can fluctuate even if all are 185/70x13

The problem is that I have 2 very new looking tires on the rear but I need to get new ones for the front...and I cannot find the same brand (Korean made)...and I don't want to replace all 4 since rears are great.
I never us 4WD unless there is snow on the road.....

Opinion/adviceand expert direction welcomed...LOL

#2 WoodsWagon

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Posted 06 December 2004 - 07:11 PM

I'm using 185's on the front and 175's on the rear, I forget the aspect ratios for them, but the rears are taller and it works just fine in the snow. works good on dirt, but binds and is hard to get out of 4wd. Dont use the mismatched tires on pavement. Doom to the center locker. use a measuring tape, preferably one of those tailor style plastic or faberic ones and measure the circumferences of the existing tires and the ones to be bought. if they're within 1/4 of an inch, it'll be fine.

#3 erik litchy

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Posted 06 December 2004 - 07:14 PM

tires are cheap why bother. if you are talking snow tyres just get all 4

#4 erik litchy

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Posted 06 December 2004 - 07:16 PM

are they Kumhos? is they are they are a very common brand, and just about the cheapest you can get. I have had a set on my jeep, very good in the wet.

#5 bgambino

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Posted 06 December 2004 - 07:22 PM

Cannot measure to compare as the good tires on the car are mounted and inflated...the tires I would look at and measure in the tire shop are not mounted/inflated---there HAS to be a difference.....?



I'm using 185's on the front and 175's on the rear, I forget the aspect ratios for them, but the rears are taller and it works just fine in the snow. works good on dirt, but binds and is hard to get out of 4wd. Dont use the mismatched tires on pavement. Doom to the center locker. use a measuring tape, preferably one of those tailor style plastic or faberic ones and measure the circumferences of the existing tires and the ones to be bought. if they're within 1/4 of an inch, it'll be fine.



#6 subiemech85

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Posted 06 December 2004 - 07:36 PM

save yourself the hastle of getting new tires, put the rears on the front, fwd
try a used tire dealer or ebay

#7 WJM

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Posted 06 December 2004 - 08:14 PM

find the same brand tires as you ahve now, and replace the front only...that way you ahve 4 same brand tires....and rotate them.

#8 Tachometer

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Posted 06 December 2004 - 09:30 PM

If your car is AWD (in other words, power being sent to all 4 wheels at the same time) then you'll want to have the same size tires for all 4 wheels (with some exceptions). My Impreza had a viscous center dif and was AWD...and if there was a constant speed difference between front and rear wheels I'd "burn out" my center dif. That's why you don't tow those kind of cars with two wheels up and two wheels down. But it also depends on what sort of dif you've got.

If your car is push button 4WD...then you can have different sized tires front vs rear...under certain circumstances. When you are just in FWD mode then it's no big deal, different sized tires won't matter. If you are in 4WD mode...
-on dry pavement...you better have the same sized tires otherwise you could damage the dif
-on wet ground/rocks/snow/slippery....then it's OK. If the tires can slip a bit then that slippage will prevent forcing your dif to do something it doesn't want to and hurt itself.

Now some AWD cars do have different sized tires front vs rear...I believe the Porsche Carerra 4 does...but its center dif is designed with that in mind.

It all depends on what type of difs you've got (torsen, viscous, open, etc) and how they were designed.

But to be safe...use the same size ;)

#9 archemitis

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Posted 06 December 2004 - 09:42 PM

tires are cheap why bother. if you are talking snow tyres just get all 4


ya... nice avitar. sometimes a new subaru can be had for what 4 new tires costs.
i run different brands front to rear, and dont worry about it. i keep them the same size all around tho...

if you only use the 4x when you are stuck, or something like that, runing around with 2 different tires wont hurt anything. but ya... 4x and different sized tires generally dont mix.

#10 AK-Brando

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Posted 06 December 2004 - 10:53 PM

..... Now some AWD cars do have different sized tires front vs rear...I believe the Porsche Carerra 4 does...but its center dif is designed with that in mind.

It all depends on what type of difs you've got (torsen, viscous, open, etc) and how they were designed.

But to be safe...use the same size ;)

I don't know how many of you are into ATV's, but a few of them are the same way. The Honda 300 4x4 and Suzuki 300 4x4 are two that I know off the top of my head have different sized tires front and rear. (24" in front, and 25" in back if I remember correctly.)

BTW - I agree on trying to keep the tire sizes the same. On our Legacy, when we ruined a tire because of a blowout, I replaced all four. Kept the other three as good spares since they still had about half the tread left.

#11 calebz

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Posted 07 December 2004 - 04:48 AM

Note:

*No center diff in a pushbutton 4wd car
*If you drive it in 4wd only on ice and snow (low traction situations) Having an exact match all the way around is substantially less important

#12 Tachometer

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Posted 07 December 2004 - 12:21 PM

Well, the pushbutton 4WD car would have a locked center dif...which I suppose isn't really a differental (sp?) because there will be no speed difference between the shafts on either side.

But I'm just being picky. :banana:

#13 bgambino

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Posted 07 December 2004 - 09:30 PM

Tachometer...I appreciate the expertise in your answer...but everyone is missing the point of my question,,,,,it is NOT "can I use different SIZE tires front vs rear".....I will keep the same 185/70/13 on all 4's

My question is ....if the fronts are bald and the rears are new (all are same exact brand)...is that bad for diff......it seems that it is
Now....I have relatively new tires on the rear...I need to buy new for the front....Since it is impossible to get the same BRAND....is it perfectly ok buy any brand/model of the same size ( I thought I heard that different brands and styles have enough difference in the circumference that it may not be a good idea for the differential)

Again, nthe car is a 91 loyale auto. push button 4WD (non turbo)--do not know what kinf of differential it has
thanks all

If your car is AWD (in other words, power being sent to all 4 wheels at the same time) then you'll want to have the same size tires for all 4 wheels (with some exceptions). My Impreza had a viscous center dif and was AWD...and if there was a constant speed difference between front and rear wheels I'd "burn out" my center dif. That's why you don't tow those kind of cars with two wheels up and two wheels down. But it also depends on what sort of dif you've got.

If your car is push button 4WD...then you can have different sized tires front vs rear...under certain circumstances. When you are just in FWD mode then it's no big deal, different sized tires won't matter. If you are in 4WD mode...
-on dry pavement...you better have the same sized tires otherwise you could damage the dif
-on wet ground/rocks/snow/slippery....then it's OK. If the tires can slip a bit then that slippage will prevent forcing your dif to do something it doesn't want to and hurt itself.

Now some AWD cars do have different sized tires front vs rear...I believe the Porsche Carerra 4 does...but its center dif is designed with that in mind.

It all depends on what type of difs you've got (torsen, viscous, open, etc) and how they were designed.

But to be safe...use the same size ;)



#14 WJM

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Posted 07 December 2004 - 09:34 PM

It wont hurt anything.

#15 thealleyboy

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Posted 07 December 2004 - 10:02 PM

Well, ideally you want a complete match front and back.

Problem is, front and back don't wear the same. Unless you are an anal rotation freak, your tires will wear out at different stages. So it always comes down to pairs. That's why I think a good compromise is matched pairs of 185/70/13's. It's a lot easier to find a good set of matched pairs, than a set of perfect 4's.

As far as performance, a bald pair of tires will always perform worse than a sticky pair. Upgrade whenver possible. If you keep the best pair of rubber you can find on each axle, and it's all 185/70/13, you can't go wrong.

good luck, John

#16 calebz

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Posted 07 December 2004 - 10:29 PM

Tachometer...I appreciate the expertise in your answer...but everyone is missing the point of my question,,,,,


I answered your question..

again..
*No center diff in a pushbutton 4wd car
*If you drive it in 4wd only on ice and snow (low traction situations) Having an exact match, whether it be brand, size or whatever, all the way around is substantially less important

#17 archemitis

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Posted 08 December 2004 - 10:23 AM

if you want fun in the snow... i had a set of toyo snow tires on the rear, and some highly siped all weather treads on the front of a wagon. feels alot more like a rear wheel drive car.




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