The The Car Doctors of the Antelope Valley Guide to Tire Specs
Dec 30, 2011
You know you need newtires, but you're not sure what type. You look at a tire to get the size: 225, 50, R, 16, 92, H. All the way to the Lancaster service center you keep repeating it over and over. You even say it over in your mind while waiting in line. Then you get to the counter and the manager asks what size you need. Then your mind goes blank.
Tire size can be confusing for many Lancaster drivers. There's so much on the side of the tire, and it's hard to keep straight.
Even though there's a lot on a tire - if you know what it all means, it's actually more helpful than confusing for Lancaster tire shoppers. Let's start with the size number.
For example, let's say a tire reads: 225 50 R 16 92 H. The 225 part is the width of the tire in millimeters - the width between the sidewalls of an inflated tire with no load. The 50 is the aspect ratio - the ratio of the sidewall height to the tread width. Off-road tires will have a higher number and high performance tires will have a lower number.
The R signifies it's a radial tire. And 16 is the rim or wheel size in inches.
The 92 is the load rating index - it's the load carrying capacity of a tire. The higher the number, the more it can safely carry. Your empty vehicle can be safe with a lower number, but you'll need a higher rating if you routinely haul heavy loads around Lancaster. The next letter is the speed rating. Not all tires sold in Lancaster are speed rated. The ratings generally follow the alphabet: the further up the alphabet, the higher the speed rating - with the exception of H - it comes between U and V (don't ask why).
There's a lot of fine print that most Lancaster area drivers probably need a magnifying glass to read. But there are a couple of other large print items of interest. One is the tread type: highway, mud and snow, all season, severe snow, etc.
And then there are the Uniform Tire Quality Grading System markings. The first is a tread wear index. 100 is the base line - a lower number is poorer and a higher number is better. All things being equal, a tire rated 200 would wear twice as long, on a government test track, than one rated at 100. These wear grades are only valid within the manufacturers product line - you can't compare with others. And it's important to note that a lower rating might be just what you want - a high performance, sticky tire has a softer rubber compound and won't wear as long, but boy, will it take those corners on twisting California roads.
The next is a traction grade. This measures the tire's ability to stop on wet pavement in government tests. A - the best, B - intermediate, C - acceptable.
Temperature grade measures a tire's resistance to heat buildup in government tests. A, B and C - from best to acceptable.
It's safe for Lancaster drivers to go with the vehicle manufacturers original equipment recommendations that came on your car. But if you want to make adjustments, you'll now be better equipped to communicate with your friendly and knowledgeable The Car Doctors of the Antelope Valley tire professional.
Today we want to talk to Lancaster drivers about timing belts. They're something that many drivers don't know much about and yet your vehicle won't run if it's broken – and it could cause many thousands of dollars damage if it does break. A broken timing belt is usually a tale of woe. Even though timing belt replacement is scheduled in the owner's manual, it's not the kind of thing that most Lancaster area auto owners remember because it's not well understood.
Let's review what a timing belt does. As most know, the engine's power is generated in the cylinders. A piston rides up and down in the cylinder. During the first down stroke, an intake valve at the top of the cylinder opens and air and fuel is drawn into the cylinder. Then the piston returns to the top, compressing the fuel and air mix. At the top, the spark plug fires, igniting the fuel, pushing the piston down in the power stroke. As the piston once again returns up in the final stroke of the cycle, an exhaust valve opens at the top of the cylinder and the exhaust is pushed out. The timing belt is what coordinates the opening and closing of the intake and exhaust valves. It's called a timing belt because the valves have to open and close at just the right time.
Now, not all vehicles have timing belts. Some have timing chains. Like the name implies, they use a chain rather than a belt to perform the function. It used to be that most engines used timing chains, which are extremely durable. The leading vehicle manufactures started using belts rather than chains to save money in the manufacturing process. So now Lancaster drivers and their advisors at The Car Doctors of the Antelope Valley are left with a component that can break. They sort of shifted the problem to us. There are two broad categories of engine design: interference and non-interference. If the timing belt on a non-interference engine breaks, the engine simply stops running. That could be very dangerous for drivers depending on where they are at the time, but it causes no internal engine damage.
Interference vehicle engines, on the other hand, will get real messed up when the timing belt breaks, because the valves will actually fall down into the path of the pistons. Things get chewed up when that happens and it'll cost a chunk of change to repair the vehicle engine.
So, what are the warning signs? Unfortunately, there really aren't any. There aren't tell-tale sounds. In some vehicles, a technician from The Car Doctors of the Antelope Valley may be able to see part of the belt for a visual inspection, but many have a cover that's in the way. The reality is that if the belt slips even one notch, it might as well be broken for all the damage it'll cause. There's no middle ground.
So how can we avoid these problems? Simply replace the timing belt when your owner's manual calls for it. It can be 60,000 miles/97,000 km; it might be 90,000 or 100,000 miles/145,000 or 160,000 km. The point is, if you have 60,000 or more miles (97,000 or more km), ask your The Car Doctors of the Antelope Valley service advisor right away if your vehicle requires a timing belt replacement.
Contact The Car Doctors of the Antelope Valley to learn more about your car's timing belt You can find us at:
Sometimes Lancaster drivers can go quite a while without a failure, but we've seen them happen within a couple of oil changes of being due. It's not worth the risk.
What does it cost to replace a timing belt in Lancaster? Well, that really depends on what kind of car you have. I can tell you that it's usually not very easy to get to the timing belt – you often have to remove some accessories to get at it. It isn't a cheap procedure, but it's a fraction of what it could cost to repair the damage caused by a failure.
At The Car Doctors of the Antelope Valley in Lancaster, we're all about trying to prevent repairs, keeping you and your passengers safe and increasing your driving enjoyment.
The Maintenance Free Myth
Dec 08, 2011
Sometimes we hear people in Lancaster say, "What's up with all this maintenance stuff? Modern cars just don't break down." While it is true that today's vehicles are extremely reliable, they are also becoming increasingly complicated and use more exotic materials than ever before. All that complexity demands higher tolerances for everything. For example, most Lancaster drivers don't realize how high tech automotive fluids have become, fluids such as engine oil, transmission fluid, coolant and brake fluid.
Did you know that a modern engine would not run for more than a few months using motor oil formulas from 30 years ago? Today's automotive fluids contain a much higher percentage of additives to protect your vehicle's components from premature wear and corrosion. Time and distances march on for all of our cars. Please don't think we're using scare tactics to get you to take care of your maintenance - but here are some personal stories we've heard to emphasize and show how important it is to get things done when they are due. Names are withheld to avoid embarrassment to those who should know better. Even though they should know better, it usually comes down to real life: time and money. But they are tales of a stitch in time saves nine.
The first comes from someone who bought a used pick-up truck for his son. The oil was clean and all the fluids were topped off. A short time later, the truck overheated on a highway in California and shut down. The repair shop diagnosed the problem: the radiator pan was corroded and dumped the coolant. Even though the coolant level was correct, it was clear that the coolant had never been completely replaced - just topped off from time to time. While this kept the engine cool, all of the anti-corrosion additives had worn out; the coolant became acidic and ate through the radiator pan. The cost: hundreds of dollars and four days in the shop. This demonstrates the need to get your coolant exchanged on schedule.
Another story involves the true cost of skipping an annual inspection. This guy took his SUV in for the California safety inspection to renew his registration. At the Lancaster inspection station, he learned that the law had changed and that his newer rig only required an inspection every two years. He was very happy to save the money. The problem was, his rear brake pads were very worn. Two months later, it was bad enough that he could hear the grind - over the radio, DVD player and the kids. He took it in to get the bad news. Both of the rear brake rotors were damaged. The left one could be resurfaced. The right had to be replaced. So saving a little on his safety inspection turned into an extra $500 over what brake pad replacement would have been. Moral of the story for Lancaster drivers: don't skip your annual inspections. The irony is that many Lancaster service centers would have done a brake inspection for free.
Next: a teenage daughter and a curb. Daddy's little princess smacked a curb when she turned into a shopping center and popped the tire. The problem came when Dad didn't get an alignment. The impact was hard enough to ruin the tire - so it was enough wreck the alignment. But instead of an alignment after the first tire, Papa ended up buying a second tire a few months later - and then an alignment.
Situation: son and wife with cars from the same vehicle manufacturer with essentially the same engine. Our staffer checked the son's maintenance schedule and saw that it needed a timing belt replacement at 90,000 miles/145,000 km. He had it done - it cost several hundred dollars. His wife's car had about 60,000 miles/97,000 km, so it should be ok for a while. Right? Wrong. The problem was that the wife had the turbo charged version. Its belt was scheduled for replacement at 60,000 mi/97,000 km. At 63,000 mi./101,000 km, the belt snapped on the interstate. The valves all crashed down into the cylinders at high speed, the entire head was shredded and it had to be replaced. The cost: several thousand dollars. Does he wish he had checked the vehicle manufacturer’s maintenance schedule? You bet he does - every time he passes a big-screen TV.
The team at The Car Doctors of the Antelope Valley in Lancaster recommends taking care of little things before they become big things. And when you take care of the little things, you can make your car run better. Plus, it is more economical to operate in California. Remember to save those maintenance records. It'll show potential buyers that you've taken care of your vehicle and it will help you get a better price. Or when you buy a used car, check those records. If there aren't any, assume that the maintenance hasn't been done and take it to The Car Doctors of the Antelope Valley in Lancaster for an inspection. Take care of unperformed routine maintenance sooner rather than later.
Hey Lancaster area drivers, are your tires worn out? What is the standard for our California streets? How can you tell on your vehicle?
While there may be legal requirements for the Lancaster area, there are safety concerns that go beyond meeting minimum replacement mandates.
Two-thirty-seconds of an inch is the depth of the tire tread wear indicator bars that US law has required to be molded across all tires since August 1, 1968. When tires are worn so that this bar is visible, there's just 2/32 of an inch – 1.6 millimeters – of tread left. It's that level of wear that's been called into question recently.
We're referring to the tread depth on a tire, it can't move surface water out of the way and you start to hydroplane.
In a safety study, a section of a test track was flooded with a thin layer of water. If you laid a dime on the track, the water would be deep enough to surround the coin, but not enough to cover it.
A car and a full-sized pick-up accelerated to 70 miles per hour, or 112 kilometers an hour, and then made a hard stop in the wet test area. Stopping distance and time were measured for three different tire depths:
New tire tread depth
4/32 of an inch, or 3.2 mm
2/32 of an inch, or 1.6 mm
So what happened with the 2/32 inch/1.6 mm tires on the car? Get this – when the car had traveled the distance required to stop with new tires, it was still going 55 mph/89 kph. Stopping distance was nearly doubled to 379 feet/116 meters, and it took 5.9 seconds.
Wow! That means if you barely have room to stop with new tires, you would hit the car in front of you at 55 mph/89 kph with the worn tires.
Now, with the partially worn tires – at 4/32 of an inch, or 3.2 mm – the car was still going at 45 mph/72 kph at the point where new tires brought the car to a halt. It took nearly 100 feet, or about 30 meters, more room to stop and 1.2 seconds longer. That's a big improvement. We can see why Consumer Reports and others are calling for a new standard.
Of course, stopping distances were greater for the heavier pick-up truck.
How do you know when your tires are at 4/32 inch or 3.2 mm? Easy; just insert an American quarter into the tread. Put it in upside down. If the tread doesn't cover George Washington's hairline, it's time to replace your tires. With a Canadian quarter, the tread should cover the numbers in the year stamp.
You may remember doing that with pennies. A penny gives you 2/32 inch, or 1.6 mm, to Abraham Lincoln's head. The quarter is the new recommendation – 4/32 inch, or 3.2 mm.
How do people feel about replacing their tires earlier? Well, tires are a big ticket item and most people want to get the most wear out of them that they can. But do you want that much more risk just to run your tires until they are legally worn out?
For us, and we would guess for many, the answer is "no".