Blog: July 2010 Archives

How to buy tires

July 09, 2010

Whenever people ask me this I always end up writing a huge email over and over, so instead of that, let me jot down some useful info for you on how to shop for tires.

What matters

Tires come in many flavors, so you need to decide what's important to you, and what is not. The axes that matter are:

Dry grip: how much overall grip do you want when you brake and turn?
Wet grip: how much do you drive in the rain, and how severe is the rain?
Snow+ice grip: do you drive to ski resorts, or does it snow where you live?
Road noise: do you drive a luxury car? Would you like it to stay luxurious?
Cost: how much are you willing to spend per year on your car for tires?
Stiffness: is it more important to have a precise, crisp feeling when you turn into a corner? Or to have a soft, smooth ride?

What does not matter

Tire dealers are like car salesmen, and they'll try to attract your attention to factors that won't meaningfully impact any aspect of your tire ownership experience. Things like:

Treadwear rating: There's no standard for how this number is assigned, so don't bother comparing it. Toyo actually makes a tire with a treadwear rating of "0" in protest of the system.
Traction rating: Same deal.
Lifetime mileage: Same deal.
Speed rating: This is not going to matter for any normal passenger car tire.
Tread pattern: Unless you're a tire engineer, you really can't glean anything useful about the tire's performance from looking at a picture of it. Most of what makes a tire grip is the rubber compound, not the tread design.
Season designation: There are a couple of rough classes (competition, summer, all season, winter) but beyond that, it's mostly not right to assume that a "Max Performance" summer tire is better than an "Ultra Performance" summer tire. Just ignore that stuff.
Run-flats: Run-flats are expensive, loud, and have compromised performance. They only do their marketing-gimmick job for certain types of damage. The rest of the time, they leave you stranded just like a normal tire. It's not worth it.
Looks: Tires are black and round, and the most important thing they do for you is felt, not seen. Big wheels, low-profile tires, fancy tread patterns--- none of these things affect the performance or lifetime of your tires.

Tradeoffs

Here are a couple of points to help you decide what type of tire you want:

Cost tradeoffs: Generally speaking, the more characteristics you try to maximize, the more the tire will cost.
Performance tradeoffs: Good grip on dry, wet, and snow are each accomplished very differently. Most tires are bad at all 3. Some tires are good at 1 type of grip, and a few tires are good at 2 types. No tire performs very well under all three kinds of conditions. If you desperately need excellent dry performance and excellent snow performance, you probably need to buy a second set of wheels.
Noise tradeoffs: Most high performance tires have lots of road noise.
Performance vs. life: Good dry grip comes from high friction, like an eraser wearing away on paper. So good performance means the tires wear away faster, and also usually worse gas mileage.
Cost vs. performance: High mileage tires last longer because they're made of a hard, low friction compound, like a metal cylinder rolling down the road. So low friction means poor performance--- less braking ability and less turning ability.
Comparing on cost: When comparing a grippy performance tire that's twice as expensive and likely to wear out twice as fast as a cheap all-season, remember: it's not really twice as expensive, it's four times as expensive per year--- twice the cost and half the life.
Savings vs. safety: Performance tires are safer tires, because they shorten your emergency stopping distance, allow you to steer around obstacles, and hold onto the road around unexpected corners. Economy tires are less able to help you avoid a car accident.

Step 1. Pick your poison

I suggest you choose one of the following classes of tire to shop for:

All-season tires

If you feel that driving is about getting where you're going comfortably, and if you want to stay safe under the most conditions, and do not care about having maximum performance, then you want some middle-of-the-road "all-season" tires. If you have an SUV, van, or light truck, you probably also want all-season tires. This is what I recommend for most people's cars. Examples of decent choices:

Falken Ziex 512: A good, cheap, all-around tire, quiet on the road, and significantly better grip than typical all-seasons. Also has a slightly stiffer sidewall, which will make the car feel more crisp. If you can find these for cheap, they're pretty good.
Yokohama Avid
Goodyear Eagle
Bridgestone Potenza

Summer + wet tires

If you're willing to spend a bit extra to make your car fun to drive, then you want "summer" tires with good wet performance (because you still want your car to be basically safe in the rain). The choice of tire compound is the single largest factor in your car's turning and braking performance (which, to me, is the fun part anyway). Wheel size, suspension, brakes, weight distribution--- none of that matters if you have bad tires. Some possibilities:

Yokohama S-Drive: An affordable but totally decent summer tire. Comes in a variety of sizes so it's a good choice if you have smaller wheels like Hondas. Decent grip in the wet and dry. Quieter than the Dunlops, which can get loud as they age.
Dunlop Direzza Z1 Sport Star Spec: National-championship winning summer tires, with good wet performance reviews from a recent Car & Driver article. I've heard complaints of road noise, but great tire otherwise.
Goodyear Eagle F1 GS-D3: Good dry grip once they get a couple thousand miles on them, and flawless wet traction. Soft sidewall, so they won't feel sharp and precise, but the grip is good once you get used to it. They definitely get loud once they're older.
BF Goodrich g-Force T/A KDW: The wet-grip version of BF Goodrich's summer tire. Softer sidewall, but good grip in wet and dry.

(By the way, if you have an SUV, van, or truck with a high center of gravity, you don't want summer tires. The high grip combined with soft suspension and poor balance could make your truck roll over if you are unlucky, which is very dangerous. Most cars are too low and stiff to roll over on a flat surface, even with very sticky tires. They will slide instead, which is better than rolling, trust me.)

Summer tires

If you live in a desert, or if you have a car that you don't drive in the rain, or if you just really like sliding around dangerously whenever it's wet out, then you can consider a broader range of summer tires that don't necessarily do well in the rain. These tend to be cheaper and have better stiffness so they'll be more fun to drive. But if they go bald when the rains come, you'll need to either drive a different car or do more telecommuting.

Hankook Ventus R-S3: A great summer tire.
Falken Azenis RT-615: A fun tire, worth getting if you get a good price. They're only mildly dangerous in the rain until they get bald. Then they're really, really dangerous.
Kumho Ecsta XS

Winter tires

If you live in a place with a long, snowy winter, OR if you travel to ski areas a lot, then you want winter tires. They're not going to handle well or be particularly good at braking on dry, but they often have okay wet performance and of course they'll keep you safe in the slush and snow. Most winter tires perform so badly on dry pavement that I recommend them only as a second set of wheels.

General Tire Altimax Arctic: I used these last season and they were really great, and not too expensive. Dry grip is good enough that you can use them year-round, although they certainly won't be "fun".

Competition tires

If you race, autocross, or go to track days, you might consider competition tires. The grip is unprecedented, and you will have a lot of fun. The up-front cost is only fractional above summer tires, but the life will be just a few thousand miles, so the cost-per-year is about double that of a summer street tire. I generally don't recommend this for anyone, but I do it. :)

Toyo Proxes R888: I have these on my Honda S2000, they're gonzo for grip and rigidity. Probably pretty bad in the wet.
Nitto NT-01: Great for light cars! Pretty sticky, long-lasting for a competition tire. I've heard it's basically the same as the old Toyo RA-1.
Michelin Pilot Sport Cup: The stock tire for the Porsche GT3 and a few other high-end toys.

Step 2. Get your specs

Not every tire fits on every car, so you need to shop only for tires that come in your size. There are two data you need to confirm fit. First, confirm your exact type of car, from the owner's manual or bill of sale:

Year	Make	Model	Trim
2005	Honda	Civic	EX Coupe

If your car comes in several trims, like "EX", "DX", "LTD", "2.0T", "VR6", etc, there's probably a sticker on the back of the car that says what it is. ("Coupe", "Sedan", and "Wagon" mean 2-door, 4-door, and 5-door, respectively, if you happened to somehow be my friend without knowing that.)

Next, find out the size of tire that fits on your car. The easiest way to do this is to just read the numbers off of the sidewall of the tires currently on the car. You're looking for 3 numbers:

Width (mm)	Sidewall ratio (%)	Diameter (in)
195 /	55 /	16

Size fudging

Note that these size specifications are not precise. Some tire manufacturers "run a little wide" or "a little tall", meaning that the carcass of the tire is actually a couple of millimeters different from what it says on the side, usually due to the shape of the tire when inflated and loaded. Because of this, you have some wiggle room with the width and sidewall ratio. For example, if your car fits 225/45/17s, it will likely also fit 205/55/17s and 215/40/17s. However, the wheel diameter (e.g. 17", 18") must match precisely. No fudging there.

Sizes and 4WD / AWD

If you have a Subaru, Audi, or other all-wheel drive car, it's important that your tires all be of the same diameter. Don't mix and match brands, sizes, or thicknesses, and keep the tires rotated so that they wear evenly. If you don't, the size differences front-to-rear will make your 4WD vehicle's center differential run hot, and you might wear out your transfer case (transmission) prematurely.

Step 3. Go shopping

Armed with your tire type and specs, it's time to shop. In this day and age, you can always shop online; please don't walk into a tire store and ask the first high school kid you bump into what kind of tires you should put on your car. Here are some good places to start, I suggest trying all of them:

Tire Rack: Big selection, will ship directly to a tire shop near you. Even if you don't buy your tires from them, it's a good site for research.
Sears: Their online site is kind of terrible, but they do carry a number of brands and have competitive prices with included installation. Tire centers are nation-wide.
Bigwheels.net: Rarely have the best prices, and are local to the bay area. But they have a really good fitment filter if you need to ... be creative with tire sizes.
Edit: I used to at least suggest "America's Tire", but my friends and I have had enough bad experiences with them that I no longer recommend them. They make installation mistakes, and they also have shady sales practices.

About cost

Some things you should know about how tires are priced:

Bigger sizes cost more. If you have 18" wheels, expect to pay as much as twice what you'd have paid if you'd had 16" wheels. Something to consider when you're buying your next car. (Also, larger wheels don't really increase performance, so you're mainly paying for the cosmetic look of a large wheel.)
Wider costs more. 255mm sport tires can cost as much as twice what 195mm passenger tires cost.
Lower profile costs more. A 245/40/17 usually costs more than a 245/50/17, because it has a thin little side wall that all the kids love.
Look for clearance sales. Tirerack (see below) sometimes sells nice tires for cheap because they're clearing out for the next model year. These tires aren't any worse, and they're often as much as half price. I always get them if I can.
Avoid over-hyped tires. Once the racing community demands a particular tire, it starts getting expensive. So unless you are buying to win a race, compare prices carefully and avoid an over-hyped tire. (Falkens, for example, have recently been getting more expensive so I no longer recommend them unless they're on clearance. I liked them because they were cheap, not because they were so good that it was worth having them at any cost.)

Researching online

Visit these online places and look at the tires available for your car in your price range. Let's take Tire Rack for example.

Go to Tire Rack
Choose your car's year, make, model, and trim level. Your car may have shipped that year with several tire choices, so you should pick the one that matches the size already on the car (see above.)
Click "View all tires this size".
Change the "sort by" to "Price"
On the left bar, click "Deselect All" in the "Performance categories" except the one you picked from above. (e.g. Winter, Summer, Competition, or All-Season.)
If you wanted summer tires, also deselect "Competition".
In the "Brands" category, uncheck the brands I don't recommend (see above).
Pick a tire.
Read its reviews. If you're concerned about road noise, the reviews are the best place to read about noise problems.
Buy tires.

Step 4. Buy

Once you've picked a tire and a seller, it's time to pony up the money and get it installed. Some tips:

Tire warrantees

You can usually buy a warrantee that will pay you a pro-rated replacement cost of your tire if it is destroyed by hitting road debris and can't be patched. I lose a tire about every 2-3 years because of this, so it does happen. However, the warrantee is not automatically a good idea: The longer your tire lasts, the more likely you are to use the warrantee. For summer and competition tires, the warrantee is usually not worthwhile--- they wear out quickly, and they wear out unevenly, so if a tire dealer sees your smoked summer tire with the nail in it, they're going to say "well it was worn out anyway" and not honor the warrantee. Personally I never buy them. But I also buy new tires at least once a year.

Drop shipping

If you buy from an online place like Tire Rack, you need to receive the tires. Don't worry, they don't actually ship them to your house. You pick an installer that is near you, and they ship them to the installer. You pay Tire Rack for the tire and the shipping, and then you pay the installer for the installation separately. If you are in the south bay, I recommend ADDS Wheel Warehouse (aka Bigwheels.net.) They cost a little more but they never, ever make a mistake with mounting, balancing, stripping your lugs, etc. Very good at what they do, and are very racer-friendly.

Installation

Installation is $60-$100 with all the disposal fees and taxes. Smaller tires are cheaper, larger and stiffer tires are more expensive. You need to have the tires mounted and balanced. You do not need to have the car aligned when you change the tires.

Buying just two tires

If you have a two-wheel drive car and/or you're terrible about rotating the tires, you may be shopping for two tires instead of four. You may find that shops like America's Tire / Discount Tire will give you grief if you try to install mismatched tires. They'll say it's because of safety, but it's really just that they're hoping to sell you more tires. So if you're not buying another set of the same tires, you might consider going to a different installer that isn't quite so upsell-oriented.

Step 5. Drive

Here are some post-purchase tips:

Let the glue dry

For a few hours after you get the tire, the bead setting goop that they use to mount the tire is still wet. During this time, the tire can spin on the rim and ruin the balancing job that the tire shop did. Avoid hard braking, turning, and acceleration for the first few hours.

Check the air pressure

About one time in 10 the installer may mis-install the valve stems and create a slow leak in your tire. It's a good idea to check the air pressure right when you get the tires, and then check it again a few days later (at the same time of day and temperature) to make sure there's not a leak. If it's different by a couple of pounds, that's ok. But if it's lost 10lbs, you probably have a leak. Take it back and have them reset the stems. They should do it for free.

Check the balance

The next day after the tires were installed, take the car up to a high speed on the freeway. (70-80mph for passenger tires, 100+ for performance tires.) Listen / feel carefully for any vibration in the steering wheel that was not present with the previous set of tires. If there is any vibration, take it back to the installer and get all 4 tires rebalanced. They should do it for free.

Check your speedometer

Unless you're buying the same tires again, it's likely that your speedometer is reading differently than it used to. Use (or borrow) a GPS such as a Garmin Nuvi and check the speedometer against the GPS ground speed indicator. I've had a difference of more than 5mph between my summer and winter tires, for example.

Break in period

Each tire compound is a little different, but in general tires take a couple hundred miles to "scrub in", meaning that the polished shipping rubber is scuffed away, revealing the grippy core rubber that you'll be driving for the rest of the tire's life. So at first, the tire may not grip as well as you expect. Take it easy. The only car wreck I've ever had was because (amongst other things) I drove too hard on new tires.

Re-check lug torque

You're probably not this paranoid, but after a tire shop has touched my car I take it home and loosen and then re-tighten the lugs (nuts) to spec with a torque wrench. I do this because (a) many tire shops other than ADDS over-torque the lugs, and (b) once in a while the tire shop will strip or cross-thread the bolt, and when you try to remove it, it will shear off. If they did this, you need to know right away so that you can take the car right back to the shop and make them replace the bolt for free. If you wait until months later when you need to take the wheel off for some other reason, they will deny that it was their fault.

Enjoy your new tires!

Posted by rus at 05:22 PM Comments (3)

Monterey Bay Aquarium

July 04, 2010

I was recently at the Monterey Bay Aquarium and took some pictures with a decent camera, which I've been meaning to do for a while. Here they are.

Posted by rus at 02:12 PM Comments (0)

Stick to the source

July 03, 2010

Now that it's confirmed that the Airbender movie is a stinker, you'll listen to me when I say, please don't go see it.

Instead, watch the original animated series, it's better than you think. Here's my pitch:

First, about humor. While the show is not intended to be non-stop laughs, yes it's for kids, so there is humor, and you'll have to tolerate that 50% of it is silly fart jokes that are beneath you. Conceded. But there are some genuinely funny-for-grownups moments in most of the episodes. Only a little below a typical Pixar movie in jokes.

Next, there are the characters. Yes, they spend some of their time moralizing about the value of friendship and teamwork and blah blah blah. Conceded. But the characters are genuinely likable, interesting, and have depth and growth that makes you want to keep watching. (Especially General Iroh and Toph--- SO AWESOME.)

The art is also excellent: yes it's a cartoon, but the directors make intriguing, cinematic choices for the sets, scenes, shots, angle, and lighting that are superior not only to most TV, but to lots of movies too. Top shelf.

Lastly, the martial art is impressively authentic. The characters have magical powers (Fire-bending, Earth-bending, Air-bending, etc) which are choreographed on real Kung Fu styles--- water-bending is Tai Chi, fire-bending is Northern Shaolin, etc. And the fight scenes are very creative: each battle is full of interesting new moves and innovative tactics, and no two are alike. It is as fresh and interesting as Dragon Ball Z is rote and tedious. Every fight in every episode is a pleasure to watch.

The show is best in season 2, but you'll want to watch seasons 1 and 3 to see how it starts and how it ends (respectively). The whole show is only 3 seasons, with a climactic and satisfying ending, so it won't leave you hanging.

Anyway, hope you enjoy it! (And don't see the live action movie. It's awful and it will spoil the real show, which is actually good.)

Posted by rus at 10:47 PM Comments (0)