Why the Different Crossing Pattern When Rotating Tires

Joined
Sep 18, 2002
Messages
6,056
Location
VA
Sorta slow on the uptake but I just happened to be YouTubing and saw where you rotate FWD and RWD tires differently.

FWD you cross the rears and move front tires straight back and RWD you cross the fronts and move rear tires straight to the front.

Why is that? It seems to me if you involve a cross of any kind that all 4 tires will see all 4 positions in the life of the tires.

Just curious what the reasoning is for the different crosses based on FWD or RWD?
 
I appreciate the video but I still want to know WHY the different rotations for FWD and RWD?
 
I've always wondered the same thing myself.
Looking in my Owners Manual, I've been doing it wrong.

I can only think it's to achieve maximum tire life after the first 5,000 miles.
To get maximum mileage, you have to have even wear.
If you never rotated your tires, I guess the drive tires would wear more ?
So your taking the tires that wear the most and switch with the tires that wear the least.

tire_rotation.gif
 
Last edited:
When RWD "pushes" a car forward, the front tires, because of friction in the bearings, will tend to toe out. But when a FWD car "pulls" a car forward, the spindles will torque about the ball joints and tend to toe in.

I don't think a solid rear axle has much play/movement for the tires, but on FWD I could see them toeing out slightly; RWD with IRS they might toe in. FWD with IRS may toe out. You get the idea.

Now take that toe change on tires and add in the effect of torque on the wheel. On a non-driven tire, it tends to be along for the ride--but on a driven tire, if the tire has toe change while under torque, I think the tread blocks are going to wear as a result. On drive tires they tend to toe-in (unless if on a solid axle), so you'd think it'd be the same tire rotation pattern, yet FWD is harder on tires and wear tires faster, due to being under torque while cornering.

At least that is my take on it... I suspect the notion that drive tires go straight back (or forward) while non-drive tires can be rotated around is from avoiding noise in case the tires got feathered (or chopped). Feathered tires that now are under torque but rotated against their wear pattern are probably loud (my guess!).

Clearly though, even on BITOG we have people who never rotate and get huge miles, while others rotate and wear 'em out in crazy fast time. Vehicle and driving habits and road conditions come into heavy play, along with vehicle condition and alignment specs. Ultimately rotation tends to be more of a recommendation--each person has to find what works best for them. Me, my FWD's seem to need it every 5k (feathering on rears) while my lone RWD might show show shoulder wear (fronts) after 20k.
 
First, the important point about tire rotation is the front to rear aspect - because those ends do different things so the tires wear differently.

But to answer the question, drive tires tend to wear more rapidly than freewheeling tires, so taking the freewheeling tires and crossing them, you are reversing the direction of travel and getting rid of heel and toe wear as rapidly as possible.
 
IME the pattern doesn't matter much, so long as you do rotate them. Front to back is the most important, and you can always do it even with rotationally directional tires. So that's the safe way to go.

Transmitting power, and steering, each causes tire wear but in different ways. RWD cars separate these functions, so swapping the tires front to back changes the wear pattern. FWD cars combine these functions up front, so the front tires wear out much faster than the rears. Here, swapping front to rear is even more important than side to side, and you may need to rotate more frequently than with RWD cars.
 
This topic has always infuriated me. There is a catastophic amount of misinformation out there. I've had "experts" tell me I can't rotate tires the way I want when they are the same size, non-directional, symmetric, and have equal tread depth. That's the last time I didn't do them myself.

Here are the indisputable facts. There are too many entities out there that tell you what to do while citing [insert "science"]. If your tires have at least 2/32", are non-directional, are the same size (non-conforming example: Mercedes with 18" front and 20" rear tires), and aren't drastically different regarding tread depth, then rotate them whichever way your heart desires (although keeping a repeated pattern of 'axle A' crossed and 'axle B' frontrear is ideal to allow each tire to be on every corner of the car. Examples of this are the left and center images in MasterSolenoid's post. Obviously, choose one, not both).

If even one of the factors listed above are not applicable, then it's a different scenario and the correct answer is based on your specific case.

It seems to me if you involve a [single axle] cross of any kind that all 4 tires will see all 4 positions in the life of the tires.
Correct, edited for clarity. This is, was, and always will be correct as long as the tires are the same size, non-directional, and have similar tread depth. Period. Not up for debate. If anyone does, I'll gladly tear their argument to shreds.
 
There are too many entities out there that tell you what to do while citing [insert "science"].



My point exactly. Although this one didn't even cite any "science." They didn't even give their own reason. Stuff like this needs to banished from the internet unless they cite exactly what their reasoning is. But they don't because it would easily be torn to shreds and invalidate their video. They just blanketed a very specific topic. What if your car has 18's on the front and 20's on the rear? What if your car has 2/32" on the front and 8/32" on the rear? What if you have directional tires?

They even contradict themselves in the video. "Always follow what your vehicle manufacturer recommends" immediately followed by "Bridgestone recommends every 5,000 miles." Well which is it Chris?
 
I hope I can go to sleep tonight. Although CapriRacer has brought me some consolation. ;)
 
Sorry to raise this thread from the dead. Mercedes says specifically to not cross rotate, only front to back and vice versa—doesn't matter if directional or not, just don't do it. I imagine it's not an arbitrary guideline they made. They don't say why though. Can anyone think of the argument made for not cross rotating?
 
My car wears the inner edge of all tires (front and rear)
And is 100% in spec, aligned by the book

The only way to counter act would be to unmount each from the rim and flip to the other side (non-directional treads)

I’ve found it best in this case to rotate on replacement of 2 front tires, I haven’t noted any change in how many miles I get and I spread out tire changes more evenly.
 
My experience with vehicle owners manuals is that vehicle manufacturers don't update tire information in their manuals very often. It is frequently the same from year to year and decades can go by without anyone even considering an update. I suspect Mercedes may be one of those.

Ya' see, in the early days of steel belted radial tires, they were prone to steel to rubber adhesion problems. It was thought that changing the direction of rotation would aggravate the problem, so all the tire manufacturers issued service bulletins recommending against cross rotation and strongly worded the bulletins to emphasize same side rotation. Since the front to rear portion of tire rotation is THEE most important part of tire rotation, I wonder if Mercedes still thinks that there is very little benefit from cross rotation and no harm with a same side rotation pattern, that they see no need to change.
 
I try not to over think it much, and just cross rotate whenever I can unless directional, or staggered.
 
Sorry to raise this thread from the dead. Mercedes says specifically to not cross rotate, only front to back and vice versa—doesn't matter if directional or not, just don't do it. I imagine it's not an arbitrary guideline they made. They don't say why though. Can anyone think of the argument made for not cross rotating?
Mercedes is kind of a laugh for me. For all their "engineering excellence" they sure put out a lot of stuff that "requires" $250 oil changes with oil that has just the right ratio of unicorn hoof shavings to pixie tears, or the engine will explode before the rest of the vehicle has a chance to self-detonate on schedule.

If all 4 wheels are the same size, and not directional, then I have to wonder what are they smoking?

If they really cared about longevity of their cars, they wouldn't be putting out such shoddy stuff that fails all the time and costs a fortune to fix.

PS, my brother keeps buying Mercedes cars and complains about not having any extra money to spend on other stuff. Their older models could go for a million miles with used shampoo in the crankcase. Shame what they have become of late.
 
Mine get rotated every 5,000 miles by Costco or Sam’s Club where I bought them since it is a free service for tires you bought there. They wear perfectly even. That is also because all the steering components are in good shape that to me is more important than rotation patterns by lot. I changed the shocks at 155K. So I did an alignment. After 20,000 miles the guy at Sam’s thought they are still new tires because the shoulders look so sharp.
 
Mercedes. When my son was in the Navy and stationed at Pearl Harbor instead of shipping his Hyundai to Pearl that Navy would have paid for there and back again he bought a Mercedes Kompressor at a base auction for about $3,000 as soon as he got there and proceeded to pour money into it. He's a nuke. Good kid but a wild child then. It needed tires as well as some dealership service like a new battery, replace belts and the like . Expensive. Had coolant issues. He sent me a photo on Christmas day he was driving it and the tires failed catastrophically with handfuls of hot rubber coming off in clumps. It was like Merry Christmas Dad, I am still alive. The front and rear tires are different sizes and cannot be rotated. New tires were over $1,200 a set in Honolulu for Goodyear Eagle Sport at the Goodyear store. The tires seemed about an inch tall and ten inches wide. Being a submarine guy he was young and flush with cash and somehow got sold every Goodyear add-on warranty you can think of including lifetime rotation and balancing on tires that cannot be rotated, towing, with free replacement in all 50 states, well he was not in 50 states he was in Oahu. Would have been more practical to just throw a set of Ling Longs on it to pass state inspection. He wound up spending more time underway under nuclear power than he did on land in Hawaii. He sold the car in Hawaii three years later to another sailor they would have shipped it back here for nothing. But by that time I think he just wanted to get out of Dodge, it was his call to make. Really nice looking car and it was quick and very tight handling. It was a daily driver though and if you have ever driven there either on the highway or in the city very little chance to go fast not for long, and at the base strictly enforced slow speed limit, the car was more for looks.
 
Back
Top