change all four tires at once

[lpgao]

Hi, guys, I am going to replace tires for my 2011 limited. I am wondering I should change them all or I can just replace front two?

BTW, "good year" tire is good enough or what brand tire is better?

[freebird]

I think you'll find that the owner's manual only recommends replacing in pairs. Your tire shop may also recommend installing the 2 new tires in the rear.

[WWWPerfA_ZN0W]

FWD or AWD?

 

FWD can be replaced per axle, might need to replace all depending on condition, like freebird pointed out.

 

AWD unless you are replacing with same exact tire (brand, size, model, etc), all 4 at once. Again, all depends on condition of old tires.

[akirby]

The best tires always go on the rear, because it's easier to recover from understeer than oversteer.

 

(side note - Smokey Yunick of NASCAR fame described understeer as when the front end hits the wall and oversteer as when the back end hits the wall).

 

Some goodyear tires are ok but I prefer Michelin, Continental or BF Goodrich. Tirerack.com has owner surveys and comparisons to help you choose.

[macbwt]

I go with Bridgestone Duelers (rated right up there with the scorpians) FWD as noted new tires to the rear if replacing in pairs. AWD confirmed all four at one time.

[perrytime]

I think people go over board with "

The best tires always go on the rear, because it's easier to recover from understeer than oversteer."

 

think about it, 2 new tires on rear, since they wear less than fronts, you will never rotate your tires to keep best on rear,

once 2 fronts wear out, 2 new ones on rear and again, no more rotations.

 

If the rears are say 50% of life, i would keep them there and put new ones on front.

[akirby]

Well that works the same whether you say they should go on the front or the rear. If you're only replacing two tires you're probably not rotating them in the first place. In the end it's not a huge difference either way.

[macbwt]

Yep Guilty as charged. I never rotate until the tires are worn, whichever ones they are get replaced with the new to the rear folks all other go to the front of the bus.

[WWWPerfA_ZN0W]

I think a major idea behind tire rotation (besides even tire wear) was also to look at what's behind the wheel: brakes, hubs, all that cool stuff Regular inspection can nip problems in the bud.

[akirby]

I think a major idea behind tire rotation (besides even tire wear) was also to look at what's behind the wheel: brakes, hubs, all that cool stuff Regular inspection can nip problems in the bud.

 

My daughter just reported it sounds like something is dragging on her 2012 Focus - pretty sure the pads are shot and it's probably scoring the rotor. Then I realized the car has 70K miles and I had not checked the brakes since the wheels were replaced about 20K miles ago. I did rotate the tires once but I can't remember checking the brake pads. Bad father........

 

Of course we're about to trade that car in on a 2016 MKX (or sell it) and give her the 2014 Escape.

[fishx65]

 

My daughter just reported it sounds like something is dragging on her 2012 Focus - pretty sure the pads are shot and it's probably scoring the rotor. Then I realized the car has 70K miles and I had not checked the brakes since the wheels were replaced about 20K miles ago. I did rotate the tires once but I can't remember checking the brake pads. Bad father........

 

Of course we're about to trade that car in on a 2016 MKX (or sell it) and give her the 2014 Escape.

Go sit in the corner and hang your head in shame!!!!! The 2016 MKX's are really nice!!!!!

[wes8398]

FWD or AWD?

 

FWD can be replaced per axle, might need to replace all depending on condition, like freebird pointed out.

 

AWD unless you are replacing with same exact tire (brand, size, model, etc), all 4 at once. Again, all depends on condition of old tires.

 

 

I know you're a trustworthy source around here, but are you sure about the AWD info here? The owner's manual doesn't say anything (in the 30+ pages of "tires, wheels, and loading") more than "It is recommended that the two front tires or two rear tires generally be replaced as a pair". There isn't anything mentioned about special considerations for the AWD system. I know Subaru has a 2/32 (1/8") tolerance between overall diameter from tire to tire; and that's the smallest tolerance I've seen. Audi Quattro systems have a tolerance of4/32 (1/4"). Ford MUST have a tolerance as well, but I haven't been able to find it anywhere, despite my relentless efforts on Google.

 

EDIT: Here's an excerpt from the owner's manual regarding the AWD system. It seems to explain that if there were a significant enough variance between tire sizes, the user would have a number of "alarms" before damaging the vehicle.

 

ALL-WHEEL DRIVE (AWD) SYSTEM (IF EQUIPPED) Your vehicle may be equipped with a full-time all-wheel drive (AWD) system. The AWD system is an active system, meaning it not only responds to wheel slip between the front and rear axles but also has the ability to anticipate wheel slip and transfer torque to the rear wheels before slip occurs. The AWD system is active all the time and requires no input from the operator. All components of the AWD system are sealed for life and require no maintenance. Note: When an AWD system fault is present, the warning CHECK AWD will display in the message center. The AWD system is not functioning correctly and defaulted to front-wheel drive. When this warning is displayed, have your vehicle serviced at an authorized dealer If your vehicle is equipped with AWD, a spare tire of a different size other than the tire provided should never be used. If the spare tire is installed, the AWD system may disable automatically and enter front-wheel drive only mode to protect driveline components. This condition may be indicated by an AWD OFF message in the message center (see Message center section in the Instrument Cluster chapter for more information). If there is an AWD OFF message in the message center from using the spare tire, this indicator should turn off after reinstalling the repaired or replaced normal road tire and driving a short distance. It is recommended to reinstall the repaired or replaced road tire as soon as possible. Major dissimilar tire sizes between the front and rear axles could cause the AWD system to stop functioning and default to front-wheel drive or damage the AWD system.

Edited April 7, 2016 by wes8398

[WWWPerfA_ZN0W]

I believe the tolerance in size differences F/R is about 3% max with AWD, that's what it is on other Ford models. So as long as all 4 tires are the same brand/model/inflation pressure, the difference between the individual tires would be tread depth, which should work out ok.

Edited April 7, 2016 by WWWPerfA_ZN0W

[PaulSchott]

Just blew a front tire on my 2007 FWD. My tires have less than 10,000 miles on them and were all put on at the same time. I put the new tire on the rear axle with the remaining front tire and the rears rotated to the front. I just think that keeping the diameters the same reduces wear on the differential. My wife's Grand Cherokee has always had all 4 replaced at the same time. I also believe that rotating front to rear on a 4 wheeler to keep the diameters equal and reduces wear on the transfer case.

[Waldo]

I also believe that rotating front to rear on a 4 wheeler to keep the diameters equal and reduces wear on the transfer case.

 

Not quite sure how a Grand Cherokee works, but this is not true on the Edge. In the Edge and all of Ford's FWD based AWD systems, the rear axle is powered through the clutches of the RDU. The computer cycles the clutches on and off to modulate the power to the rear axle, so having different diameter tires on the rear would not cause any extra wear on the system, it would just slightly change the amount of torque transfer to the rear from what the computer intended.

Now if you have different tires on the left vs the right, that would make a difference, as it would cause the pinion in the differential to spin a bit more.

[akirby]

FWD based part time AWD is completely different than a full time 4WD system like the JGC - as Waldo described.

[WWWPerfA_ZN0W]

Supporting Waldo's assertion is this article in GEARS on Ford's Intelligent All Wheel Drive system:

Introducing Ford’s Intelligent All-Wheel Drive System GEARS 2009_9_20.pdf

 

The 3% I was thinking of is not directly related to AWD. It is a "global" 3% tolerance based on the tire/wheel size coded into the PCM, which means that overall wheel/tire height should be within 3% of that expected by the PCM to not trigger a fault, such as P1635. The Owner's Guide is kinda vague on this, but you can see a little bit of information in the "Roadside Emergencies" section.

[wes8398]

I believe the tolerance in size differences F/R is about 3% max with AWD, that's what it is on other Ford models. So as long as all 4 tires are the same brand/model/inflation pressure, the difference between the individual tires would be tread depth, which should work out ok.

 

I'm not trying to be a contrarian here, but if you're getting a matching tire in terms of size, purpose, speed & load ratings, etc; I really don't think the brand and model matter either. The main concern is that the overall circumference of the tire isn't significantly different than the rest. The definition of "significant" is where reality gets a bit lost in the forest of unsubstantiated opinions and misinformation. Also confusing the situation is the fact that this definition differs from between many makes and models.

 

I've personally received 5 different "answers" from Ford technicians on this topic. I called a couple local dealerships and got contradicting answers, so then I called some of the largest dealerships across Canada and the same thing happened. I've heard everything from "all 4 MUST be replaced at the same time or you'll damage your (insert big, scary, expensive part here)", to "this is becoming one of the biggest tire sales tactics out there...don't fall for it", to a basic "just use your common sense... if you put tires on there with a 5" difference in circumference, you're probably going to break something eventually".

 

One thing that keeps coming back to my mind is that we have a full blown computer monitoring this stuff for us (at least, to some extent). If we're putting stress on the transmission or RDU (rear drive unit), things are going to heat up and trip a code. The computer already does this in other situations (see my excerpt above), so why wouldn't it with regards to tires being out of spec?

 

 

Supporting Waldo's assertion is this article in GEARS on Ford's Intelligent All Wheel Drive system:

Introducing Ford’s Intelligent All-Wheel Drive System GEARS 2009_9_20.pdf

 

An excerpt from it that's directly related to our topic here:

 

The I-AWD system isn’t sensitive to tire size differences between all four wheels and isn’t sensitive to being towed with one axle raised off the ground.

Take it for what you will, I guess. The owner's manual for my 2011 Edge Sport AWD explicitly states NOT to tow an AWD-equipped vehicle by the front or rear wheels only. It says their AWD vehicles MUST be towed with all 4 wheels supported (flatbed or dolly). Something doesn't add up with that article, or Ford's just covering their asses. Who knows...

Edited April 8, 2016 by wes8398

[Waldo]

 

I'm not trying to be a contrarian here, but if you're getting a matching tire in terms of size, purpose, speed & load ratings, etc; I really don't think the brand and model matter either.

 

True, but just because the size on the sidewall is the same, doesn't mean the actual size is the same. Tire size is governed by industry standards but those standards are pretty loose. So loose in fact, that you can have the exact same tire made with two different sizes printed on the side (like say 235/65 and 245/60) and still legally sell it.

 

I once worked on a series of tires where one was labelled a 215 but was actually 221, another was labelled 225 but was actually a 223 and a third was also labelled 225 but was actually a 227. All of them were OEM tires made by the same company.

[wes8398]

Waldo - I completely agree. I wouldn't even say that different models from the same brand could be trusted.

 

One nice thing about online tire shopping is the plethora of information they provide about the tire though. I was recently shopping for 2 replacement tires which would be matched up with 2 others that have 2 summer's worth of driving on them. I measured the used tire's total circumference and then took to Tire Rack, Discount Tire, etc and made sure that what I bought listed a circumference as close to the used tires as possible. I got under a 1/4" difference with a completely different brand (I'll NEVER EVER EVER buy Pirelli tires myself... they're the most expensive junk you can buy).

Edited April 8, 2016 by wes8398

[lpgao]

Thanks for all of your inputs. I like to report my story here to share with you.

 

I bought 4 good year tires which is cheapest brand out there. But when I got car shop the mechanic said first: good year tire is not good, cheap but not last long. Then he told me rear pair are still good so I should just buy a set new for front.

 

I looked carefully and found the quality of good year is not as good as Pirelli on my edge. Secondly, I found the front two almost worn out but the rear set is nearly like new. That means front tires working hard? New ones should go front.

 

BTW, I brought rear set back to home and save for next time change I just buy two new Pirelli.

[enigma-2]

I had a flat couple of months ago. Put on the spare and stopped at Sam's Club. They repaired the tire but we're not certain it would hold as the nail was right at the edge of sidewall. He was telling me that should the tire not hold air, they didn't carry the brand (were not purchased there) and they would have to replace all four. Asked why and he said that on my AWD the tread has to match. Differences in tread would cause problems with the stability system when driving on ice.

[Waldo]

I had a flat couple of months ago. Put on the spare and stopped at Sam's Club. They repaired the tire but we're not certain it would hold as the nail was right at the edge of sidewall. He was telling me that should the tire not hold air, they didn't carry the brand (were not purchased there) and they would have to replace all four. Asked why and he said that on my AWD the tread has to match. Differences in tread would cause problems with the stability system when driving on ice.

 

The stability system is designed to account for that, it doesn't actually know how much grip can be produced by each tire, it just reacts to what's actually happening. But it is true that mixing tires is never a good idea, it can ruin the steering and handling feel of the vehicle and make it more difficult to control in an emergency.

 

To lpgao - if you're going to put two tires in storage, I'd put the two Pirelli's in storage (or sell them) and put all 4 of the same tires on the vehicle. Also sounds like you have not been rotating them, so make sure you do that every 10K km or so. Keep in mind that even in storage, tires do age. If you keep those things in your basement for 5 years they will not be as good as they are now.

[enigma-2]

One area nearly everyone forgets about is the spare. It's supposed to be changed when you put on a new set of tires (or every 6 years).

 

(from the owners nanual) "You should replace your spare tire when you replace the road tires or after six years due to aging even if it has not been used."

[macbwt]

Where is the spare located?