Tuesday, October 11, 2011

Its just rubber...How important could it be?


Well, has it turns out it is very important. Coming home from my in-laws last week, we had a really bad rain storm on I95. While I was driving, doing about 50 mph with my hazards on, I watched more then one person go flying by me, only to be to found in the middle guardrail or spun off into the trees to the right of the highway. Why? Rubber or should I say the lack there of. You see what these people failed to do was either maintain their tires or they were driving  too fast for the amount of tread left on their tires.

Coming from the dealership I can say for certain that most people have NO FREAKING clue what their tires look like or how to maintain them. Another thing they do not like to do is BUY new tires. For some reason people seem to think your just trying to get their money when you tell them they have bald tires. I have been amazed sometimes that people even made it there in the first place! Even when you show people how bad they are, they up right refused or would say "yeah I have a friend who...." Good for you, but please do something about it! Do not blow it off. Remember this is the single most important maintenance item that is severely overlooked . Its your link between the road and vehicle.

Maintenance of your tires is fairly simple. Maintain the correct air pressure and make sure they are going in a straight line. Seems easy enough right? The tire pressure for each vehicle is different. To find out what the tire pressure is for your car, just simply open up the driverside door look down into the door jam area (can  be on the body side or I have seen them on the door itself) for Hyundai they should be on the body side. For example, on my 2003 Elantra GT the correct pressure for the OEM tires is 30psi. Please remember that check your pressures BEFORE the car starts to move (when the tire is cold). Once in motion the friction of the tire on the road makes heat and with heat the gasses with in the tire expand. This in turn will increase pressures with in the tire. So if you had a low tire pressure prior to starting out it will say that your at the correct pressure, when in all actuality it is not. Having proper tire pressure not only insures the life of the tire, but also the correct contact patch with the road. There are cases where you might want less pressure, but these are going to be for situations like sand and maybe snow.  So unless your driving on the beach or trying to get out of a snow bank, make sure the pressures are correct. I could also go on about pressures for the sports car enthusiast, but for this particular article lets just stick to the basics, ok? if you have any questions by all means ask away!

Going straight...

You might have guessed it already, but I'm  referring to the car's alignment. The alignment is very important and should be checked atleast once a year. Depending on the vehicle, there are multiple things to adjust. Being about Hyundais I will use them as my example. A four wheel alignment is going to be your best bet (I'm not sure they do just two wheel alignments anymore...uh?) this will make sure that your front and rear tires are facing in the proper direction and within the OEM limits. Toe is a term that refers to front of the tires and the direction in which they are pointing on the X-axis. Toe out means just that, the front of the wheel is off center towards the outside of  the body. Toe in being the opposite. The tires are facing in toward the middle of the car. Toe will reek havoc on your tires when its off, even just the littlest bit. "Feathering" is when you can run your hands over the tire and feel slight little ridges of the backside of the tread (see picture to the right).  Camber is another adjustment. If this is not with in specs can cause some serious damage to your tires as well. Especially if the car is not engineered to have alot of camber. Camber is the position of the top of the tire relative to the Y axis (toe being the X axis...you dont remember X and Y??? haha look it up). Negative camber while good for twisty roads and race cars can kill the inside of the tires if it is excessive. Yeah I'm looking at you Hellaflush crew (dont get me started on that...I could go on for days). This means that the top of the wheel is pushed toward the center of the vehicle. Whole positive camber is just the opposite with the top of the tire moving away from the body. You can see here that I had a little more camber then this tire was designed for (-2 degrees). The tread progressively gets worse as you move toward the inside of the tire. With negative camber you are running on the inner part of the tire most of the time. This is good for cornering because of the McPherson strut suspension on my Elantra will "gain" camber as the wheel is turned. So inputting negative camber helps to keep the contact patch large while going through a corner. On the flat roads of Florida, all it manages to do is eat the tires up. 

Caster is the third adjustment but being that its usually fixed in a position and does not vary (atleast for Hyundai vehicles) there is no need to say much about it, except that its the angle at which the strut is in the Y axis. Most cars have a little bit of caster to help absorb bumps and make the wheel comeback to center with little or no help from the driver.

More tire wear...here are some pics of some tires I had laying around. 

You can see that on this particular tire, it looks like it has a very bumpy contour and will extend over the entire tread. Its not smooth at all. This is generally what a tire will look like when you have a bad strut. The strut is unable to control the bouncing of the spring, so the tire suffers the consequences by bouncing along on the road. These tires will ROAR like a mofo while on road too. More noticeably the faster you go.

This lovely tire had an internal failure. You can obviously see the tread coming through. this was making my wife's steering wheel wobble. At about 30mph it was very noticeable and the faster you went the worse it got. She decided to tell me about 2 weeks after...whoops! This was a blow out waiting to happen! 

Tread...How low an you go!

Well all tires have wear bars built into the tread. All you have to do is look. By law the lowest the tread can go is 2/32. This is the lowest of low and if you start to go lower then that, lets just say that your gonna end up in the woods like my buddies did on I95 that rainy day. If you do not have a tire depth gauge like this one here (sorry for the blurry pic). You can even use a Penny. With Lincoln's head facing down, the tread should cover up his head, if it does not then your looking to get a new set of tires. This last pic is of the wear bars. When you start to see these bars level with the rest of the tread then it is time for new tires. The picture below you can see raised portions in the grooves of the tread, these are the wear bars. Also if you go up to the second picture, you can see the wear bars are flush with the remaining tread.

I almost forgot!!!

Rotating your tires is also very important for tire wear. On Front Wheel Drive (FWD) cars this is very important because the front wheels propel the car and turn the car. These front wheels can and will wear much quicker then the rears. Depending on the tire you have on there will dictate how you can rotate your tires. Hyundai recommends that you cross the front tires to the back (opposite sides of the car from where they came from) and then move the rear tires forward on the same sides. IF you rotate your tires like this every 6k or so (think every other oil change) then every tire will be in ALL positions at some point and tire wear should be even through its life. Please remember though if you have directional tires, you can NOT rotate the tires in this manner. You simply move the front to the back and vise versa (on the same sides of the vehicle). I have seen plenty of "techs" put directional tires on the wrong side of the car. What happens is that water does not channel out from the center of the tread like it was designed to do AND directional tires are designed to go in one direction, if you put them on the wrong side of the car then they have the possibility of unraveling, Not a good scenario.

In the future I'll expand on this to include sizing, tread wear, and speed ratings. For now though, make sure you have your pressures correct! Your tires will thank you. Happy motoring.

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