Subaru tire need
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Originally Posted By: redbone3
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
It's not the differentials that are the problem - it's the weak PDUs that overheat.
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
It's not the differentials that are the problem - it's the weak PDUs that overheat.
Originally Posted By: redbone3
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
There is difference between open differential and limited slip differential. LSD will overheat when different wheel speeds are present for prolonged time. Donut spare is temporary use.
Krzys
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
There is difference between open differential and limited slip differential. LSD will overheat when different wheel speeds are present for prolonged time. Donut spare is temporary use.
Krzys
Originally Posted By: redbone3
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
Apparently you dont understand how AWD works?
try putting a 4wd truck in 4wd with a donut spare on it..? I guarantee it wont work any better.
Its not in the differentials, its how the power is transferred it expects the front and back of the car to be moving the same speed.
If you have mismatched tires they wont be.
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
Apparently you dont understand how AWD works?
try putting a 4wd truck in 4wd with a donut spare on it..? I guarantee it wont work any better.
Its not in the differentials, its how the power is transferred it expects the front and back of the car to be moving the same speed.
If you have mismatched tires they wont be.
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Originally Posted By: Miller88
Originally Posted By: redbone3
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
It's not the differentials that are the problem - it's the weak PDUs that overheat.
Not sure what you're referring to, power take off's? Subaru uses MPT (multi plate transfer) in the automatic transmission models (up to a 60/40 front/rear torque bias)and a viscous center differential (constant 50/50 front/rear torque bias) in the manuals. Subaru AWD is designed as AWD from square one, not the typical front wheel drive with AWD as an after thought that's used by most competitors in the class.
Originally Posted By: redbone3
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
It's not the differentials that are the problem - it's the weak PDUs that overheat.
Not sure what you're referring to, power take off's? Subaru uses MPT (multi plate transfer) in the automatic transmission models (up to a 60/40 front/rear torque bias)and a viscous center differential (constant 50/50 front/rear torque bias) in the manuals. Subaru AWD is designed as AWD from square one, not the typical front wheel drive with AWD as an after thought that's used by most competitors in the class.
Originally Posted By: Rand
Originally Posted By: redbone3
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
Apparently you dont understand how AWD works?
try putting a 4wd truck in 4wd with a donut spare on it..? I guarantee it wont work any better.
Its not in the differentials, its how the power is transferred it expects the front and back of the car to be moving the same speed.
If you have mismatched tires they wont be.
Besides the point. If the system can't compensate for .5" difference in circumference it's a [censored] design. If you have to shave a brand new tire down to match three worn ones, it's a [censored] design.
Originally Posted By: redbone3
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
Apparently you dont understand how AWD works?
try putting a 4wd truck in 4wd with a donut spare on it..? I guarantee it wont work any better.
Its not in the differentials, its how the power is transferred it expects the front and back of the car to be moving the same speed.
If you have mismatched tires they wont be.
Besides the point. If the system can't compensate for .5" difference in circumference it's a [censored] design. If you have to shave a brand new tire down to match three worn ones, it's a [censored] design.
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You drive the chrysler 2.7 and are talking about [censored] designs? That turd of an engine should have been aborted before the 2nd trimester of development. Don't throw stones if you live in a glass house !!
Originally Posted By: LoneRanger
You drive the chrysler 2.7 and are talking about [censored] designs? That engine should have been aborted before the 2nd trimester of development! Don't throw stones if you live in a glass house !!
raffing. Out loud.
Let's face it some folks here read "Subaru" and just lose it. Calm down. I'm purely hetero and drive a WRX.
You drive the chrysler 2.7 and are talking about [censored] designs? That engine should have been aborted before the 2nd trimester of development! Don't throw stones if you live in a glass house !!
raffing. Out loud.
Let's face it some folks here read "Subaru" and just lose it. Calm down. I'm purely hetero and drive a WRX.
Originally Posted By: redbone3
Originally Posted By: Rand
Originally Posted By: redbone3
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
Apparently you dont understand how AWD works?
try putting a 4wd truck in 4wd with a donut spare on it..? I guarantee it wont work any better.
Its not in the differentials, its how the power is transferred it expects the front and back of the car to be moving the same speed.
If you have mismatched tires they wont be.
Besides the point. If the system can't compensate for .5" difference in circumference it's a [censored] design. If you have to shave a brand new tire down to match three worn ones, it's a [censored] design.
Not beside the point. ENTIRELY the point. I take it you will never own an AWD vehicle. This is not a Subaru thing. This is a "how AWD systems work" thing.
Originally Posted By: Rand
Originally Posted By: redbone3
The whole reason for a differential is to compensate for one wheel spinning faster than the other. If a differential can't do that we need to coin a new word: almostadifferential, subdifferential, kindadifferential?
Apparently you dont understand how AWD works?
try putting a 4wd truck in 4wd with a donut spare on it..? I guarantee it wont work any better.
Its not in the differentials, its how the power is transferred it expects the front and back of the car to be moving the same speed.
If you have mismatched tires they wont be.
Besides the point. If the system can't compensate for .5" difference in circumference it's a [censored] design. If you have to shave a brand new tire down to match three worn ones, it's a [censored] design.
Not beside the point. ENTIRELY the point. I take it you will never own an AWD vehicle. This is not a Subaru thing. This is a "how AWD systems work" thing.
Honda S2000 is rear wheel drive with LSD. The OEM tire sizes are 215/34-17 front and 245/45-17 rear, rear's circumference is about 0.3" more than front.
If the rear is flat Honda recommends replace the donut to the front and mount the front to the rear.
If the rear is flat Honda recommends replace the donut to the front and mount the front to the rear.
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Originally Posted By: redbone3
2.7 has 91K miles with no problems. If it is down a quart of oil, I don't have to buy 5 identical quarts, I can use any quart I like.
The 2.7 is a known sludger. [censored] design. Better use identical quarts !
2.7 has 91K miles with no problems. If it is down a quart of oil, I don't have to buy 5 identical quarts, I can use any quart I like.
The 2.7 is a known sludger. [censored] design. Better use identical quarts !
Originally Posted By: redbone3
2.7 has 91K miles with no problems. If it is down a quart of oil, I don't have to buy 5 identical quarts, I can use any quart I like.
You are missing the point.
AWD demand's nearly identical tires due to the fact that its AWD and on a hard surface where they dont slip...
Its not a bad design its how AWD works.
If you dont like it don't buy any kind of awd car ever.
yes it sucks to have to have 4 matching tires.
its one of the things that go with the AWD territory.
What you are complaining about would be similar to complaining a V10 Expedition gets 14mpg(or less)
It just is how it is.
2.7 has 91K miles with no problems. If it is down a quart of oil, I don't have to buy 5 identical quarts, I can use any quart I like.
You are missing the point.
AWD demand's nearly identical tires due to the fact that its AWD and on a hard surface where they dont slip...
Its not a bad design its how AWD works.
If you dont like it don't buy any kind of awd car ever.
yes it sucks to have to have 4 matching tires.
its one of the things that go with the AWD territory.
What you are complaining about would be similar to complaining a V10 Expedition gets 14mpg(or less)
It just is how it is.
An honest question here for those with real AWD experience. Does the need to more carefully manage the tire wear on AWD add a substantial cost to ownership?
I've talked to a number of Subie owners who have had stellar reliability experience, but I haven't questioned them about the tires.
Thanks.
I've talked to a number of Subie owners who have had stellar reliability experience, but I haven't questioned them about the tires.
Thanks.
I've found that the tire wear on my subaru is virtually identical on all four tires. I've been blown away by how even and uniform the tire wear is. There might be a difference of .5/32"-1/32", but that's it. I average around 20k per year, and I don't rotate my snow tires that are on from Mid-November to Mid-March. I run all seasons from mid-March to mid-November, and I only rotate those maybe once in mid-July or so.
Originally Posted By: doitmyself
Does the need to more carefully manage the tire wear on AWD add a substantial cost to ownership?
No, because if you have permanent AWD, then all 4 tires wear out at about the same rate more or less, so you end up replacing them in sets of 4 anyway.
The only time an issue arises is if you end up damaging one of the tires beyond repair. In that case, you can have it shaved down to the same tread depth as the other 3, but how often does that happen, really?
Does the need to more carefully manage the tire wear on AWD add a substantial cost to ownership?
No, because if you have permanent AWD, then all 4 tires wear out at about the same rate more or less, so you end up replacing them in sets of 4 anyway.
The only time an issue arises is if you end up damaging one of the tires beyond repair. In that case, you can have it shaved down to the same tread depth as the other 3, but how often does that happen, really?
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What Quattro and sxg6 said. On my Forester, the torque split is 50/50 front/rear continuously and the weight distribution of the car is pretty even front to rear as well. All four tires wear the same, there is no need to rotate the tires. Now, you do go through tires faster this way of course, because you're grinding the tread on two add'l tires than most other vehicles do, because of Subaru's AWD system that continuously drives all four wheels all the time. The car also handles really well because of this balanced torque distribution and weight distribution.
My Outback has the 4EAT with the older style of AWD power split. Basically it is a constant state with a max of 90/10. That being said I rotate my tires every 10K to keep the wear even, the fronts wear slightly faster as they carry most of the weight and do most of the braking.
Have almost 50K on my Primacy MXV4 tires right now. I haven't seen any difference in tire ownership coming from a RWD vehicle.
Have almost 50K on my Primacy MXV4 tires right now. I haven't seen any difference in tire ownership coming from a RWD vehicle.
I rotate mine to even out the steering wear from the fronts.
I forgot to mark my tires last fall. they all have 12k on them and were within 1/64th inch.
the limit of my repeatability with a depth caliper on rubber.
The ones on the front had more brake dust though
I forgot to mark my tires last fall. they all have 12k on them and were within 1/64th inch.
the limit of my repeatability with a depth caliper on rubber.
The ones on the front had more brake dust though
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