Breaking in new Tires?

[EAM 17806]

Do new tires really need to be broken in to ride smoothly; if so, for how long?

[TJ Hopland]

I would say no.   What sort of tires?    How different are they from what you had on that car previously?    IF you were switching between bias and radials you would feel a difference.   Even radial to radial there could be a difference.     

Have you checked the air pressure?   Assuming they are similar tires to your previous ones are you running the same pressure?   Often times with and old (sometimes any car) the tire shops will inflate them to the max for the tire which with more modern tires could be in the 40-50 psi range.   If you are used to 30 40 will feel like you are riding on the rims. 

The other likely possibility is you have a combination of not especially well balanced out of the box tires and a minimally skilled tire balance tech.   

[Eric DeVirgilis CLC# 8621]

In my experience the fresher the tire, the better it performs in all ways. Never heard of any tire that improves with age and/or use.

[EAM 17806]

I would say no.   What sort of tires?    How different are they from what you had on that car previously?    IF you were switching between bias and radials you would feel a difference.   Even radial to radial there could be a difference.     

Have you checked the air pressure?   Assuming they are similar tires to your previous ones are you running the same pressure?   Often times with and old (sometimes any car) the tire shops will inflate them to the max for the tire which with more modern tires could be in the 40-50 psi range.   If you are used to 30 40 will feel like you are riding on the rims. 

The other likely possibility is you have a combination of not especially well balanced out of the box tires and a minimally skilled tire balance tech.   

The new tires are "American Classic" radials 235X75X15 exact size as prior ones. Tire pressure is kept at 28 psi (all four) as stated for 76 CDV on placard by CADILLAC..  Information throughout "GOOGLE" and "BING"state new tires usually need a break-in period of 500-700 miles of easy driving to give the tire a chance to acclimate itself to the road.  Is there any basis to this reasoning?  EAM

[TonyZappone #2624]

No

[EAM 17806]

No

Then I suggest you check-out the varies tire authorities on Google and Bing search sites that state YES!  EAM

[Eric DeVirgilis CLC# 8621]

  Then I suggest you check-out the varies tire authorities on Google and Bing search sites that state YES!  EAM

Depends on the "authority" you're talking to I guess.

Cannot count the number of tires I've bought after 30+ years in the car business, dealt with a dozen tire dealers and spoken with other car dealers, customers and car owners in general.  Before today, I have never heard one single utterance of the phrase "tire break in". 

Sounds like an excuse to get the driver to become acclimated to defective tires or tires that were poorly made and/or designed to begin with.

There are many opinions as they say and mine is that it's pure bunk. 

[Bob Schuman]

I did hear of this many years ago, but tend to agree that it is nonsense.

[David Greenburg]

If anything, I think the opposite is true.  Not specific to vintage car tires, but I know some modern tires are criticized for losing performance after a couple of thousand miles.

[hornetball]

Well, it depends.  Racing tires will last longer if you do an initial, controlled "heat cycle" of around 70% race pace and then a rest period prior to hard use.

This has absolutely nothing to do with classic whitewalls on a Caddy.  Note that all the driving we do with our cars would qualify as easy cruising.  After all, that's the point!

There are also cases where a tire can flat spot due to minimal use and the heat of driving evens things out.  However, this should not be an issue with new tires assuming they were stored correctly.

Note that new tires will still have mold release agent on them that wears off in the first few hours of driving.  You can definitely tell the difference with performance driving.  It is wise to take it easy, especially on wet roads, while the release agent scrubs off.

[76eldo]

 Big NO.

New tires are the best they will ever be.

[35-709]

Agree with all of the NO responders --- never heard of such a thing.  My father was a General Tire dealer back in the '60s and '70s.

[TonyZappone #2624]

Tom Lester was a friend of mine.  After he sold his tie company, he was still very proud of his name on them. I had a set of 7:50X17 on a 5900 pound Pierce-Arrow.  I balanced them, I shaved them, they vibrated til the day I replaced them with a set of B.F. Goodrich that remain on the car ten years later and have never needed to be balanced.  They either are balanceable (word?) or not.  As far as Diamondbacks, I think they are the best.   '58 convert, '47 convert, been on 15 years at least, no problems.  Ride like a modern car.  I don't like to drive on bias belt tires, and only do when I have to.  (some wire wheel cars in the thirties I don't think are safe on radials)

[Cape Cod Fleetwood]

   The new tires are "American Classic" radials 235X75X15 exact size as prior ones. Tire pressure is kept at 28 psi (all four) as stated for 76 CDV on placard by CADILLAC..  Information throughout "GOOGLE" and "BING"state new tires usually need a break-in period of 500-700 miles of easy driving to give the tire a chance to acclimate itself to the road.  Is there any basis to this reasoning?  EAM

Forget the placard, its ornamental. Inflate to the max as stated by the manufacturer of the tire, deflate if necessary to the minimum as stated by the manufacturer to tune the ride quality. Most radials are 32-35psi.

[Eric DeVirgilis CLC# 8621]

After speaking to many tire dealers and professionals in the auto business, the overwhelming consensus is that tire inflation pressures listed on the door placard is what should always be followed. Overinflation is not desirable for a number of reasons including premature wear and loss of ride and handling quality.

I cannot comment on appropriate tire inflation pressures for radial tires on a car originally equipped with biases. At any rate, EAM's car is a 1976 which was originally equipped with radials therefore the pressures listed on the door placard are appropriate in this case.

https://info.kaltire.com/the-right-tire-pressure-why-the-maximum-isnt-the-best/

[35-709]

TODAY'S radial tires are not the same as those built in 1976.  If today's radial tires were being built in 1976 the recommended pressure would be 32 to 35 pounds --- 30 being the absolute minimum.  Using the recommended pressure in a type of radial built in 1976 for a radial built today is --- call it what you will --- but not something one should do, IMO.  You will be hard pressed to find a car today even half the weight and size of a 1976 Cadillac with a radial tire pressure recommendation of 28 pounds.  Modern radials require more pressure as is aptly noted in the link that Eric provided above.

This discussion comes up here every so often, bottom line --- your car, your tires, run what you like.   

[Eric DeVirgilis CLC# 8621]

It came as a surprise to me that the door placard lists just 30 PSI (F/R) for a 2010 Yukon with curb weight of 5,500 which is at least as much as a 1976 Coupe deVille. Maximum GVWR is another ~ 1,500 lb above that.

I would reckon anything from 28 to 30 PSI would be fine for EAM's car.

[35-709]

Much bigger, heavier tires on the Yukon too that can handle more weight.  Our 2017 Honda CRV is placarded for 35. 33.
30 pounds (as I mentioned) would be an absolute minimum safe pressure for today's passenger cars and modern radials and I would be adding air to any of my tires up to 32 to 35#s that checked as low as 30 pounds.

[Dan LeBlanc]

I ran my 77 at the 24psi front and 28psi rear recommended in the glove box.  Those tires were NOT happy.

[35-709]

Darn right. 
Doesn't anyone remember the Ford Explorer/Firestone tire rollover uproar back in 2000/2001?  Ford pointed their finger at Firestone, Firestone pointed theirs at Ford but the real bottom line was that people weren't checking their tire pressure and keeping enough air in their tires.  I wouldn't run my tires at the minimum, nor the maximum (unless maybe pulling a heavy trailer).