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New tires too hard

I’ve recently replaced the tires on my Subaru Outback 2008 with Hankooks, warrantied for 50K. The car used to have a nice smooth ride. With these new tires, I feel like I’m driving on hardened rubber. I feel every bump in the road. I’m afraid it may eventually hurt the car’s ball joints–not to mention shaking up my kidneys. Any advice?

Have you…ahem…checked the tire pressure? Look on the driver’s side door jamb for a placard that will give you the specs on what the pressure ought to be. Buy a decent quality pressure gauge from an auto parts store to keep in the car. Check the pressure regularly - first thing in the morning before driving is best.

I agree step one is for YOU to check your pressures.
Too many tire shops just zip in some air, good enough for the sidewall specs, without checking the vehicle specs.

A decent quality gauge is one with a dial or digital, NOT a “pencil” gauge.

Just about every time I’ve bought tires the tech leaves them over-inflated.

I’ve heard people complain about static shocks when getting in and out of the car after they installed certain brands of tires, mostly the lower costs brands. These tires apparently have more plastic-like stuff in them than the others. Plastic is more prone to causing static shocks than rubber apparently. If that’s the case with the tires above, I could imagine one symptom might be a stiffer ride, as the plastic-stuff might not be as flexible.

The other posters are right. The first thing to check is the tire pressure. But the materials the tires are made of may be playing a role too. If static-shocks start happening, that would be a clue.

What model Hancook tires are they? Tires have different ride characteristics. I have this gauge (model H60X):

http://www.ghmeiser.com/dial.htm

Please give us the size and, more importantly, the LOAD and SPEED rating that are stamped on the side of the tire right after the size, like “P205/65R15 95T”. The new tires may be different/higher load or speed ratings than the originals, causing a difference in ride.

Ditto on checking the cold air pressure.

I agree on checking the tire pressure. I have yet to find a tire shop that doesn’t grossly overinflate tires during installation. I have no idea why they do this, but it seems to be a very common practice. Last tires I bought were inflated to 55 psi with a sidewall maximum pressure listing of 44 psi.

Just some food for thought but if the OP has not bothered to check the tire pressure on the new tires maybe those new tires are correctly inflated and the OP was driving around previously on worn, underinflated tires which were giving a cushier than normal ride.

Other than that, I agree with the overinflated scenario.

Check the date code- make sure you tires haven’t been sitting in a warehouse for years.

George in SanJose,

I’m sorry, but what causes the static electricity build up in tires is the silica in the tread compiund of many modern tires - especially tires with low rolling resistance. Tires with pure carbon black tread compounds don’t have this issue (much - it’s a matter of degree!).

You will find most tires today have several “work arounds” - and one is providing a very small strip of carbon black compund down the center of the tread.

Most tire stores DO know the correct psi unless you are buying from “here today, who knows about tomorrow” used tire shops. I don’t work at one but it’s in their best interest when warrantees are involved to keep the pressure up to specs. Still, always check new tires after a few miles usage.

If you purchased from a national chain store, go in for a free pressure check. I do it once a month since it takes a whole 2 minutes. Also, when they rotate tires, they always rebalance them too.

Subaru, for a few years, put cheap tires on the Outbacks. My 1997 had some fine Michelins that got 73K; my 2001 had the crappy Bridgestone marshmallow tires that got 42k and my 2006 had the lousy Potenzas that made it to 40k. I put Hankooks and the ride was a bit “sturdier” but wow, cornering is like a cheetah chasing a yummy lil wabbit compared to the Potenza’s blubbery, slug like performance.

Also, if your old tires had noticable wear on the outside of front or on one side of the car compared to the rest of the tire(s), you need a 4 wheel alignment. It’s not uncommon for Subarus to need this and with what you spend on tires (my '06 had 17" tires and going just one size up makes for much more money spent), it should be an instand add-on purchase. If the alignment is off, you will have more friction pronounced by the new tread fighting an ever unaligned 4 wheels. May not have anything to do with the ride, but talk to someone who designs tires and alignment can really make difference, especially with AWD designed cars. Your old tires (and you!) got used to gradual but pronounced wear from unaligned wheels. Most places will do a 4 wheel alignment for about $80. Check the mechanics files for shop recommendations from fellow Car Talk junkies.

“If you purchased from a national chain store, go in for a free pressure check. I do it once a month since it takes a whole 2 minutes.”

Since your tires will have built up pressure–possibly considerable pressure–by driving the car before the pressure check takes place at that tire store, you will not get an accurate check of the pressure.

The only way to ensure that you get an accurate pressure check is to do it yourself, at home, before the car has been driven for the day, with your own tire pressure gauge. Be sure to buy a high-quality dial-type pressure gauge, as the cheap gauges are frequently not accurate enough, and tend to break after just a year or two.

Checking tire pressure is something that every car owner can–and should–do for himself/herself.

Here are my experiences, for what it’s worth, with this phenomenon of overinflating tires during installation, and who did it. Several years ago, I bought a set of BFG’s from Sears for my Buick. They were inflated to 45 psi when I picked the car up. Door sticker calls for 30. My father always buys tires from an independent tire shop run by a pair of Hispanic brothers. They always set the tire pressure between 40 and 50, and my father does the same thing, which I don’t understand. Maybe because that’s what those guys do? A few months ago, I bought a couple of used tires from an independent tire shop that is also run by Hispanic brothers (another inexplicable common phenomenon around here). They inflated them to 55 psi. When my brother bought a set of Goodyears for his Jeep from a Discount Tire Direct franchise shop, they were also set around 50 psi. I don’t get it. Maybe they’re stuck in their childhood when their bicycles needed that kind of pressure in the tires?

Here’s a related question. If you take the reading before you drive, how far can you drive to a gas station and still have a cold psi reading? If the nearest station is say 2 miles away.

If that gas station is only 2 miles away, and you drive at no more than…let’s say…30 mph, the pressure should not change.

However, the easiest way to do things is to buy your own tire inflator that plugs into the cigarette lighter. That way, you can check your tire pressure in your own driveway, and correct it right there if necessary. And, by carrying the tire inflator in your trunk, you have something that will help you to get the car to a tire repair place in the event of a small puncture while you are traveling.

I would go out on a limb and say that, even if the gas station were farther away than that, to go ahead and check them. By checking them at all, you are doing far more than most motorists, so that in itself is commendable. Two miles will make very little to no difference in pressure, so that should give you an accurate enough reading. First thing in the morning in your driveway is still best, but a two mile drive to a gas station is way better than not checking at all.

Driving a short distance then filling them a couple pounds over will be fine.
When the trained gorillas mount the tires then over fill by 15 pounds, that’s a problem.

sccubsfan wrote:
If you take the reading before you drive, how far can you drive to a gas station and still have a cold psi reading? If the nearest station is say 2 miles away.

I’m afraid I don’t get the point of your question. If you measure it at home and then again at the gas station, you’ll know if it’s gone up and by how much.

A drive to a station 2 miles away is not enough to warm up the tires. The general theory is that pressure increases about 1 psi for every 10 degrees. The only way a tire could rise 10 degrees in 2 miles is if the brake were dragging.

I too always check my pressure using one of my good gages after having tires installed, and I always find them to be high in pressure. Shops have to overpressure tires to get the bead to seat (pop the bead), and for some reason they often don’t drop the pressure all the way back down to the proper pressure after installing them.

One suggestion: get yourself a decent dial gage at a parts store (or an automotive tools & equipment store if you’re lucky enough to have one near you). It’s worth the small investment. Pencil gages are notoriously inaccurate.