New Tires Question

smart
fortwo

#1

I recently bought 4 new tires for my car. They are identical OEM tires, same brand and style, same size, same everything. What I found remarkable is that the new tires ride much smoother than the old tires did. They absorb bumps better and ride somewhat quieter. I wonder why this is. The original tires came with the car and had been in service about 8 years but with 62,000 miles on them, they were wearing thin and it was time to replace them. So my question… being identical to the original tires in all respects, why are my new tires riding so much smoother than the originals?? Thanks all.


#2

Lets see, their new, construction of tire could have changed in 8 years, might be same brand but the original were made for mass production for the vehicle manufacture. Also the old tires flexibility degraded over a long period so you did not notice. Now you have new tires so you are more aware of ride and handling.


#3

New tires are quieter and the rubber hasn’t hardened with age. That would make the ride better.


#4

There’s also more of it. That alone makes a big difference.


#5

I switched from Michelin to bridgestone at 85k miles, a big difference in thumps from the road ie worse, switched back to Michelin at 150k miles much nicer, I am sure there is much difference between tire brands and models but glad you are happier with your new tires. Reviews were not much help.


#6

On my 2012 Altima, I replaced OEM Michelins with Firestone from Costco and so far quite happy with road noise and how it handles bumps. It is not worse than outgoing Michelins in noise, but road grip looks to be substantially better (although it is hard to measure objectively). The only thing I can tell: it does not spin front wheels as much as I used to get from OEM Michelins, even when new. I’ve spent quite some time researching tirerack.com, primarily road tests, only partially what people say in reviews. My prior experience with “whatever” Firestone was terrible, but it went out with car I sold :slight_smile: I would say selecting particular model for your priorities is more important than a brand selection.


#7

I am sure your original tires rode just as well when new. Brand new tires have much thicker rubber and are softer when new, The grooves and sipes are deeper and have more deflection over road surfaces. The degradation of the tire as it ages and wears is so gradual that you do not notice it happening until you put on new tires and feel the sudden improvement.


#8

Exactly! tires get noisy as they wear because of loss of rubber tickness on the treads All tires do this.


#9

New tires have more rubber and just like adding more padding to a sofa, new tires absorb bumps better.


#10

Except that they are not identical in all respects. OEM tires are designed to be cheap as well as fit specific criteria defined by the car maker. These include ride and handling but are also skewed to low rolling resistance for better fuel efficiency. That skew generally hurts the ride.

Aftermarket versions of the very same brand and model tire doesn’t have to meet that fuel efficiency requirement and can be made to ride better. Plus the tire could have been improved over the last 8 years to give a better ride AND the high fuel efficiency.


#11

Not exactly.

It is true that OE tires are generally skewed towards better RR - and they get that by tread compound.

There is a technological triangle for tread compound involving treadwear, traction (especially wet traction) , and rolling resistance. To get good properties in one area, the other areas have to be sacrificed. That’s why OE tires have a bad reputation. The OEM’s sometimes overstep the boundaries and the result is poor performing tires - at least for the properties consumers are interested in - treadwear and traction.

Ride and handling are similarly in opposition to each other - and it is all controlled by the stiffness of the lower sidewall - typically a thing called the filler. (and just to be clear: Ride = impact harshness, not vibration, and Handling = steering crispness, not grip.)

And while it may seem that a stiff riding tire would generate lower rolling resistance, most RR is generated in the tread and the amount of deflection a tire experiences is due to the inflation pressure, not the stiffness of the casing. In other words, it doesn’t matter who makes the tire, within a small window, one can predict that amount of deflection knowing the inflation pressure and size.

I’ll agree to the second part that OEM tires are designed to the vehicle manufacturer’s specs - but cheap? Not exactly.

While it is true that the OEM’s pay quite a bit less than you or I pay at the retail level, it’s because the OEM’s buy tires on the order of a thousand a week (or more) to be delivered on the same day of the week to the same location, for years. That makes setting up an assembly line and a shipping system very easy and inexpensive.

But the tires themselves are not cheaply made. They are made on the same equipment out of basically the same materials that all the other tires in that plant are made of. The difference is in the details. Typically what is different is the tread compound - see above.