Why don't we rotate tyres but you rotate tires?

Question

Is planning a regular rotation of new tyres over their lifespan a good or bad plan?

From many posts I've seen here and elsewhere on the web, motorists in the USA seem to see rotating tires as a task which ought to be undertaken at regular intervals. By rotating tires, I mean moving their position on the vehicle, so moving them from the front to rear axle for example.

In the UK, we seldom do this. Indeed one of the biggest tyre fitters in the country actually advises against the practice (see link here)

I've just fitted a set of four tyres to our 2012 VW Golf and wondered if it is worth rotating them over the life of the tyres. Is there any advice that is clearly for or against the practice and are there any studies which back this up?

Answer 1

tl dr: Kwik Fit is full of crap. It's good to rotate tyres (and tires, too :o).

The entire idea of rotating tires is to keep the wear relatively similar (or even), front to rear. If rotation is done at the specified intervals, the only time you'll have a weaker tire of appreciable wear is when it's time to replace all four.

I don't know what the end goal of Kwik Fit is, but there are several things they state on their website which are VERY disturbing to me having to do with tire (tyre) rotation. Here is what I'm talking about.

Note: I'm taking quotes from the page you linked.

• Partly worn tyres are more likely to experience punctures – particularly in wet weather conditions.

What does wet weather have to do with whether a tire is punctured or not? Absolutely nothing, as far as I can tell. Road hazards will flatten a tire just as quickly in dry weather as it will in wet.

• Front tyre deflation will create an under-steer effect which is easier to control than over-steer (the effect produced by a rear tyre deflation)

Understeer by definition is: "(with automobiles) having a tendency to turn less sharply than is intended". Does anyone believe if you have a sudden tire deflation on the front end you are going to be able to turn the vehicle more sharply than if you lose it on the back end? I certainly don't.

• In the unlikely event that a tyre deflates suddenly, then it is easier to control the vehicle if this occurs at the front of the vehicle. For improved handling and stability it is now recommended that the ‘best’ tyres should always be fitted at the rear of the vehicle. This is irrespective of whether the car is front or rear wheel drive.

~70% of the braking power and most all of the steering power is controlled from the front end of the vehicle. If you suddenly lose air pressure in a front tire, you've now lost a major portion of both, which means you've lost a major amount of control of the vehicle. This is especially true if you are traveling down the motorway at 70mph (which I believe is the typical posted speed on the M1, right?). By having a blowout on the rear of the vehicle, you maintain almost all of your braking power and lose very little of your turning power (rear might want to drift some). If you lose a front tire, it will drag the car in the direction of the lost tire. If the pull is great enough, it can most likely cause an accident, either through dragging the car into other traffic or causing the driver to lose control and creating a single car accident.

It seems to me this tyre company has an agenda. One in which they want their patrons to wear out their tires faster, so they'll come back and buy more tires. Having the weaker tire on the rear of the vehicle is not going to create as big of an issue as having it on the front.

Other things they state there on the website are accurate. You don't rotate tires on a vehicle where the front and rear are different sizes (like you'd see on some sport vehicles). I have never seen a car which has a specification for asymmetric tread pattern at one end of the vehicle and symmetrical at the other, but I guess there could be. In this case, you don't want to rotate the tires, either.

Answer 2

Just thought it was an interesting topic, so googled around a bit for actual sources.

First of all, some (or maybe all) BMW's actively recommend NOT rotating tyres. Cartalk covered this in one of their shows, and here are the most notable quotes:

TOM: We've always felt that tire rotation is of marginal value in terms of saving you money. Why? Because the cost of tire rotation roughly equals the amount you'd save by extending your tire life.

RAY: You can see why mechanics like it. Not only is it an easy few bucks for us, but it also gets your car into the shop again so we can sell you other services — like engine flushes and fuzzy-dice reupholstering!

So that might explain the reason for its popularity in the USA.

Regarding BMW they say

TOM: BMW cites safety because the front and rear tires develop different wear patterns. And for at least a little while — until the wear evens out, which is the point of tire rotation — you might have slightly inferior handling with newly rotated tires.

They argue to only do it if the car is already having other maintance which requires taking the wheels off. Unlike BMW they believe that rotating tyres is a good thing, just not worth the money or trouble by itself:

TOM: So, our feeling has always been that if the tire rotation is free, do it. In other words, if you're having your brakes checked, and the wheels are already off the car and your mechanic is nice enough to put them back on different wheels for nothing, then do it. That's what we do for our customers.

and

TOM: Still, we see nothing wrong with rotating your tires. No harm will be done, in our opinion. But if you're paying your BMW mechanic $125 an hour to move your tires around (and eight bucks a wheel for rebalancing, too), it's very unlikely you'll save any money in the long run, Larry.

Sadly I wasn't able to find any actual studies. Maybe it's worth posting on skeptics.SE, there are a lot of experts there when it comes to finding (obscure) studies. Still I feel like this source draws from a bit more authority than anything else I could find.

Answer 3

You always fit the best tires on the rear. Why? They don't motor*, don't steer and barely brake - why can't rear wheels just be casters?

The rear tires are your rudder

They keep your car from spinning out. To be technical, they provide stability in yaw, and they don't steer, so vertical stabilizer is more correct. Ever seen those on the front of an airplane? Nope, and for good reason!

src

Driving a curve (and some other things) put sideways force on every tire. Here's the key question: In poor traction, will your front or rear tires break away first?

If your front tires break first, your car will seek to go in a straight line. (understeer). As it gets near breakaway, you'll notice - the steering will be less responsive. If you are properly trained, you will "turn into the skid" (align the steer wheels with the direction you are actually going). Why? Wheels have best sideways traction when rolling straight - when cocked at an angle, traction is much worse. By aligning wheels with the skid, you get maximum traction and soon recover control. (and of course this will correct the rear problem too.)

If your rear tires break first, there is nothing you can do about it. You can't steer your rear wheels into the skid. The increasing angle makes traction even worse - a vicious cycle, which is why a spin-out is hard to stop! I've spun 360 on a tight cloverleaf freeway on-ramp going 25 mph in simple rain. That's when I grokked the "rudder" thing, and put my best tires on the rear.

Best tires go on the rear because you want the rear to break away last.

The rudder is their main thing

Of course they support the weight of the car, but in front engine cars, 60% of your weight is on the front. When you brake hard, it shifts the weight even more forward! So most of the braking is done by the front.

And the vast majority of cars are front-drive, so the rear wheels don't even provide power. They might as well be casters, except for the rudder thing!

Sideload, steering and power/braking all tax the same traction

A tire has a finite amount of traction. Sideload, steering, and power/braking all "dip out of that same pool" of traction. If all of them together add up to more traction than available, the wheel must slip!

On the front wheels, that's much more manageable - because you control power (on a front drive car), braking and steering. You can back off any of those and put that traction back in the pool for something else to use. You can't do that with the rears, unless it's a rear-drive car and you can lift off the throttle.

In fact, in a rear-drive car, if you punch the throttle hard, you can use up all the traction and cause sideslip. It's very easy to over-do it and spin out entirely... but done right, it is drifting or a bootlegger's turn, and swings the rear around right where you want it.

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* Presuming FWD cars, which are the vast majority of cars on the road today. I cover RWD cars at length in the non-TLDR section, and frankly, RWD drivers tend to be knowledgeable and understand their car is an exception, and don't need this explained to them.

Answer 4

Check with the tyre manufacturer. If anyone would know, it'd be them - not a shop full of work experience kids.

When rotating tyres, move the fronts to the back, and the backs to the front on the same side. Do NOT cross-rotate them; that can cause premature wear.

Why is the UK different? Because of consumer expectations driven by marketing. In the UK, I had a car (Vauxhall Astra 2001) which had 20,000 mile oil change intervals (http://oil-change.info/vauxhall-astra-g-engine-oil-capacity/). In the US, 3,000 mile intervals are the generally accepted standard.

Answer 5

The idea of "tyre rotating" is to spread or average out the wear and tear on the tyres, across all the tyres. The wear and tear comes down to several things, misalignment, suspension types (beam vs. coil) etc., and the driven vs's free rolling wheels, and the load distribution between them. Basically the idea is to get all the tyres wearing more or less evenly, so replacement can be made, all at the same time, without say the two front tyres being fully worn, and the rear tyres being 2/3rds worn...

That being said IF your tyres are near the end of their service life, and are all more or less evenly worn then don't bother, but if the front and back sets, have more than a marginal amount of difference in the thread depth, say 2mm on the front driven wheels and 4mm on the rear, then rotate them.

And keep your tyres inflated to the specification on the tyre, as some times the car manufacturers specify a lower pressure for ride comfort - as a cheap suspension boost.

Answer 6

As a UK driver. In 40 years and over a million miles, I have never rotated my tyres. Never seen a recommendation to do so, either.
Maybe because I have never had a brand new car and never used a main dealer for servicing. I suspect it is dealer culture, to make you think they are looking after you and add a little something(!) to the bill.

Answer 7

Is planning a regular rotation of new tyres over their lifespan a good or bad plan?

It is not advisable, instead put the better tires on the back, for safety reasons.

This is what understeer vs. oversteer means in real life:

This is what happens with your car when the rear tire explodes

This is what happens if your front tire explodes

Now if you are a trained racing driver, and you always sit behind the steering wheel 100% concentrated, hands at 3 and 9 position, you can have fun with a little oversteer. For all others, best tire goes to the back!

You know, you can change tires by 2´s? So you won´t actually save anything by swapping!

Answer 8

Interesting. I've seen user/service manuals state vastly different mileages for rotations.

For Subaru (and likely many AWD vehicles), they recommend every oil change (5,000 - 7,500 miles or so)

For other cars it's every 15,000 miles.

The justification for AWD being that the tires all need to be within 1/4" or so of tread so that the center differential is not overworked.

Answer 9

Just a note on their contradiction here:

... For improved handling and stability it is now recommended that the ‘best’ tyres should always be fitted at the rear of the vehicle. This is irrespective of whether the car is front or rear wheel drive.

So if you do a few burnouts and your back tires are more worn than your front, according to their recommendation you are to put the better ones on the back (or in other words rotate your tires).

That contradiction aside, it's far more dangerous to lose a tire which is part of the steering system. I would want better on the front - if I were force to choose.

I believe they are assuming that someone will not rotate their tires for three years, then move the bald tires which were on the front, onto the back and drive for another three years.

If rotation is done regular how can it possibly be bad? even tread all around the vehicle must be the safest setup.

I see this is one of those things like using Nitrogen instead of Air to fill tires if you don't regularly maintain.

Answer 10

Each wheel location on the car will create its own unique wear pattern on its tyre. Rotating tyres between these positions causes a period of a few hundred miles in which the tyres are not worn to shape for that position. Since the optimum grip occurs when the tyre is worn to shape for its location, rotating the tyres introduces a sub-optimal grip for a few hundred miles.

Answer 11

Some empirical evidence I have is that rear tire blowout is no issue at all.

One show I watched a few years ago simulated front tire blowout on a turn with 130kmph. The driver said that the car wanted to throw him in one direction but he firmly held the steering wheel and things were ok. I guess it also depends on driver concentration and reactions.

I've been in situations where rear tires have been slipping in very slippery road conditions. I was driving slowly so I could recover. Car was AWD but behaved like a rear wheel drive so I couldn't use acceleration to help myself (I've experimented with that, just balance was more to the rear wheels).

I personally prefer to have even wearing so I am rotating tires. Every year I change tires twice — for winter and summer conditions. So it is easy to do. Just tires need to be labeled after removing.

For some reason my tires don't wear much BTW. I don't think I'm a very calm driver. But for some reason my thread depth doesn't go down quickly.

I wonder what causes most wear.

Answer 12

A main source for this kind of information should be the owner's manual. Every vehicle I have owned, the manual had a tyre rotation schedule.

Besides that fact, it is claimed that poor rear tyres are more dangerous because of the risk of losing the back end. I'm sure that's true for Formula 1 cars (and it used to be the case that they used much bigger tyres in that back many years ago, though it's not the case anymore), but I don't think a passenger vehicle doing anything remotely normal is at risk of this; in regular driving, more benefit will come from better steering and breaking. As a source for this, since many years ago I live at a place where we have snow/ice for 6 months a year, and I have yet to see a FWD vehicle lose the rear in any kind of situation.

Answer 13

I've never rotated my tires on a regular basis.

Usually, I buy new tires two at a time, put them on the front wheels, move the front tires to the back, and discard the (much worn) rear tires. That's all the rotation I do. If someone argues with me about that, I just shut them down with the tires rotate as you drive.

Putting your best tires in front is important -- a blowout in front is very dangerous, as you can lose control over steering.

The exception is when all four tires are in the same condition (like when I've just bought a vehicle). Then, I wait until I need to replace them, and buy two high-quality tires for the front and two cheaper tires for the back. Then when the back tires are worn, I use the plan described above.

Answer 14

Given that

• ‘best’ tyres should always be fitted at the rear of the vehicle.

And

• In the UK most cars are front wheel drive, and therefore the front tyres wear quickest

I see no point in rotating tyres other than when replacing tyres, so the new tyres always go on the back.

I suspect in the USA there are a lot more cars without front wheel drive....