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miri
04-12-2008, 10:49 PM
I need to replace the front tires on my car. It has 4 of the same tires but due to the tires not being rotated them, the front tires need to be replaced, while the rear are fine. Is it unwise to replace the front tires with a different brand but same size?

miri
04-12-2008, 10:49 PM
can this post be moved to the garage please?

middlehead
04-12-2008, 11:01 PM
That's the sort of thing that will infect your soul, curve your spine, and keep your country from winning the war.





I'm definitely not a "car guy," but I don't see a problem with differing brands as long as you're certain the dimensions match.

ObiDon
04-12-2008, 11:05 PM
it's okay as long as they are they're in the same class/type of tires as the ones you're keeping.

in other words, you wouldn't want to mix rain treads with all weather, or a pair of h-rated tires with a pair of super-sticky z-rated tires, and so on.

the guys at the tire shop should be able to give you some good recommendations for decent matches assuming they aren't just trying to sucker you into buying four new tires.

ObiDon
04-12-2008, 11:06 PM
Originally posted by: middlehead
That's the sort of thing that will... keep your country from winning the war.
crap! i forgot about the "war" factor!

summit
04-12-2008, 11:14 PM
your tires will get aids.

Throckmorton
04-12-2008, 11:21 PM
Not if there is a differential between the different ones. Tire sizes are not consistent any more than shoe sizes are. So if your car is AWD, you need the same brand front and rear. If it's FWD or RWD, it doesn't matter.

IronWing
04-13-2008, 12:01 AM
Put the new ones on the back and move the backs to the front. Also, Throckmorton is correct but only if the AWD car has a locked center differential, which is unlikely under most conditions.

0roo0roo
04-13-2008, 12:30 AM
its fine as long as they are on the same end.
just be sure one end doesn't have ridiculously more grip than the other. but if your treds aren't that worn on the old set it'll be fine.

Captante
04-13-2008, 12:34 AM
Originally posted by: ironwing
Put the new ones on the back and move the backs to the front. Also, Throckmorton is correct but only if the AWD car has a locked center differential, which is unlikely under most conditions.



Not true ... my Subaru had a very specific warning in the owners manual stating that all four tires needed to be the same size or the transmission could be damaged.

stonecold3169
04-13-2008, 12:48 AM
In most states the front tires will need to be the same on both sides or it automatically fails (so that shouldn't affect you), and in some states all tires need to match... ask at the tire shop before you plop your moolah down

TitanDiddly
04-13-2008, 02:04 AM
Originally posted by: Captante
Originally posted by: ironwing
Put the new ones on the back and move the backs to the front. Also, Throckmorton is correct but only if the AWD car has a locked center differential, which is unlikely under most conditions.



Not true ... my Subaru had a very specific warning in the owners manual stating that all four tires needed to be the same size or the transmission could be damaged.

What year Subaru?

MBrown
04-13-2008, 12:10 PM
Where I work, we tell our customers that the tires on the drive axcels have to be the same. For instance if its a front wheel drive, the front tires have to be the same, if its rear wheel drive, the back tires have to be the same. If its 4x4 all tires should be the same, and if its AWD all tires must be the same. If a customer comes in with a 4x4 or AWD and they still want to get two different tires than what they have after we tell them our policy, then they have to sign a special document stating that anything that goes wrong with the vehicle is not going to be covered by us in any way and it also voids are own free balance and rotation warranty.

PandaBear
04-13-2008, 12:33 PM
Rule 1: Same axle, same tire (including brand model and age, no old/new mix)
Rule 2: More traction in the rear to avoid spun out, that means new tire in the back unless you go from ultra high perf to chinese knockoff.

Toastedlightly
04-13-2008, 02:08 PM
Originally posted by: PandaBear
Rule 1: Same axle, same tire (including brand model and age, no old/new mix)
Rule 2: More traction in the rear to avoid spun out, that means new tire in the back unless you go from ultra high perf to chinese knockoff.


I heartily disagree w/ rule 2. Steering wheels are the most important to have traction on.

alkemyst
04-13-2008, 05:36 PM
Originally posted by: middlehead
That's the sort of thing that will infect your soul, curve your spine, and keep your country from winning the war.





I'm definitely not a "car guy," but I don't see a problem with differing brands as long as you're certain the dimensions match.

Dimensions and tread type need to match. Most will say stick with matched per axle though as long as the tread types are the same.

Running 4 different brands of tires is not going to be optimum.

Captante
04-13-2008, 06:43 PM
Originally posted by: TitanDiddly
Originally posted by: Captante
Originally posted by: ironwing
Put the new ones on the back and move the backs to the front. Also, Throckmorton is correct but only if the AWD car has a locked center differential, which is unlikely under most conditions.



Not true ... my Subaru had a very specific warning in the owners manual stating that all four tires needed to be the same size or the transmission could be damaged.

What year Subaru?


2002 Impreza Outback w/automatic transmission ... the warning stated that the transmission could overheat & be damaged by driving with different sized tires over more then a short distance & in fact use of the mini-donut required insertion of a fuse which disabled power to the rear wheels.

Edit: Most likely doesn't matter much but it was actually an '02 not '03.

IronWing
04-13-2008, 07:20 PM
Originally posted by: Captante
Originally posted by: TitanDiddly
Originally posted by: Captante
Originally posted by: ironwing
Put the new ones on the back and move the backs to the front. Also, Throckmorton is correct but only if the AWD car has a locked center differential, which is unlikely under most conditions.



Not true ... my Subaru had a very specific warning in the owners manual stating that all four tires needed to be the same size or the transmission could be damaged.

What year Subaru?


2003 Impreza Outback w/automatic transmission ... the warning stated that the transmission could overheat & be damaged by driving with different sized tires over more then a short distance & in fact use of the mini-donut required insertion of a fuse which disabled power to the rear wheels.

Well I've learned something new. I'll have to look up Subaru's AWD setup.

Zenmervolt
04-13-2008, 09:54 PM
Originally posted by: ironwing
Originally posted by: Captante
Originally posted by: TitanDiddly
Originally posted by: Captante
Originally posted by: ironwing
Put the new ones on the back and move the backs to the front. Also, Throckmorton is correct but only if the AWD car has a locked center differential, which is unlikely under most conditions.



Not true ... my Subaru had a very specific warning in the owners manual stating that all four tires needed to be the same size or the transmission could be damaged.

What year Subaru?


2003 Impreza Outback w/automatic transmission ... the warning stated that the transmission could overheat & be damaged by driving with different sized tires over more then a short distance & in fact use of the mini-donut required insertion of a fuse which disabled power to the rear wheels.

Well I've learned something new. I'll have to look up Subaru's AWD setup.

Viscous couplings do not like speed differential between wheels for extended periods of time. Any AWD system using a viscous coupling should not have different sized tires used for very long at all.

ZV

miri
04-13-2008, 10:37 PM
Originally posted by: Captante
Not true ... my Subaru had a very specific warning in the owners manual stating that all four tires needed to be the same size or the transmission could be damaged.

My original question was in regards to having different brands, not sizes. Do the brands need to be the same as well?

Zenmervolt
04-14-2008, 12:26 AM
Originally posted by: miri
Originally posted by: Captante
Not true ... my Subaru had a very specific warning in the owners manual stating that all four tires needed to be the same size or the transmission could be damaged.

My original question was in regards to having different brands, not sizes. Do the brands need to be the same as well?

This is a qualified "no". Manufacturing variances do crop up between brands, which can lead to slight differences between the sizes of "identical" size tires across different brands. This can cause issues with certain AWD systems as mentioned.

You will always want the best tires on the rear. If you lose grip from the front tires, it's less dangerous since the rears will cause a spin if they lose grip. In street-driving situations with average drivers, understeer is always preferable.

Overall, I will always recommend replacing all 4 tires at the same time unless you cannot afford to do so, but as long as you keep the tires the same on a given axle and do not have AWD, you should be fine.

ZV

Savij
04-14-2008, 01:54 PM
Originally posted by: Toastedlightly
Originally posted by: PandaBear
Rule 1: Same axle, same tire (including brand model and age, no old/new mix)
Rule 2: More traction in the rear to avoid spun out, that means new tire in the back unless you go from ultra high perf to chinese knockoff.


I heartily disagree w/ rule 2. Steering wheels are the most important to have traction on.

Video at top right...good part is about 1/2 way trough the vid: http://www.prnewswire.com/mnr/michelintires/27813/

jagec
04-14-2008, 02:29 PM
Originally posted by: Toastedlightly
Originally posted by: PandaBear
Rule 1: Same axle, same tire (including brand model and age, no old/new mix)
Rule 2: More traction in the rear to avoid spun out, that means new tire in the back unless you go from ultra high perf to chinese knockoff.


I heartily disagree w/ rule 2. Steering wheels are the most important to have traction on.

Lose traction in the rear, you won't be able to steer anyway.

RWD, AWD, or WWD, the better tires always go on the back.

LS21
04-14-2008, 02:33 PM
i prefer to have better tires on the front... better steering (as someone mentioned), but also very important is better braking. you ever had close call when you had to brake and end up inches behind somebody? tires could make difference between that a 500$ bill. thats a mild example. i wouldnt worry about a spin out due to relative lessened traction (due to differences in rear tires) unless youre really very pushing the limits... which applies in fewer cases

Jessica69
04-14-2008, 04:17 PM
But as for grip, half-worn tires tend to grip better than brand new tires......at least that's what SCCA racer friend of mine said. That's why in the street divisions, the ones that restrict you to street tires, they use shaved tires.....essentially half-worn tires instead of new. Shaving the tires down decreases the squirm in the tread and the tires are somewhat grippier.

Like Tire Rack has on its site:

"any tread design breaks up the contact patch into smaller elements and additional deep tread depth (required to enhance wet traction) allows tread block squirm which will reduce dry performance. This means that tires typically provide their worst wet traction ... and their best dry performance just before they wear out."

"A shaved tire's tread profile will usually result in a slight increase in the width of the tire's contact patch putting a little more rubber on the road. The resulting shallower tread depths reduce the tire's slip angle, increases its responsiveness and help stabilize its cornering power by minimizing tread block squirm. Minimizing tread block squirm also reduces heat buildup and the risk of making the tire go "off" by overheating its tread compound. And in many cases, shaved tires used in competition actually have a longer useful life than tires that begin being run at full tread depth."

"Most tires begin with 10/32" of starting tread depth. Our experience is that shaving them to about 6/32" will provide a noticeable improvement and is a good starting point. However, it's also important to remember that once used, all tires will be much less effective during the next competition season. Therefore we recommend that tires be shaved to a depth that is sufficient to last for no more than one competition season. If it is very important to you to do well in the one event you run a year, a tire shaved to about 4/32" will further enhance your performance."


So, what I'm getting at is that a half-worn or less tire should provide better grip than a brand new tire, at least if the grip of the two different tires is fairly close to begin with. The notion that a brand new tire will grip, at least in dry, better than a slightly worn comparable tire is not quite correct........