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Checking your Mustang's tires.

Written by Mustangworld.

Lots of pics, I hope your on the net at 28.8 or faster.



You hear a lot about performance parts on the web, but the most important part of your whole stang are the tires. Reeves Calloway likes to quote that "every component in a car is in place to make the tires work better... driver included" This is very true. We wanted to show you some tire tips and other info.

First, checking your tires:

1. Know your rim and tire. Let's look at the stock 16" rim and tire. There is a plastic center cap covering the 5 lug bolts on the rim. But notice the tire tread, sidewall, and valve stem areas. Inspect your tires for nails, bolts, splinters and any sharp metal in the tread and sidewall area. Look at the sidewall for bulges and cracks or gashes. Tire breakdown
2. Check your tire valves for any damage as well. Make sure they are all properly capped. This photo shows the cap removed. Here is where you check the air pressure in your tire. You can also check if your valves are leaking air by putting some soapy water (or spit) on the valves and check for bubbles. More on air leaks way below. You can also buy special tire caps that have mini air pressure gauges in them, a little red indicator shows you if you need air at a glance (though these caps can get ripped off easy). Valve Stem
3. Your tire may also have a tire weight mounted on the rim. This is there to "balance" your tire. If these weights came off, you can hear a noise while driving your stang with an un-balanced tire. A repetitive rumble type noise. Using weights also ensures proper tire wear. You may be lucky and get a tire mounted that needs no balance weight. These weights can be mounted on the inner rim side for a better appearance. Tire weight
4. THIS IS YOUR LITTLE BUDDY ! If you don't have one, get one TODAY! This is a tire air pressure gauge. They cost around $2 for a USA made one. Check your tires often, at least once every two weeks. Keep one in every stang you own. Your little buddy
5. Hold the gauge up to the valve, push in and seal it up. A plastic stick will pop out and give you your measurement in PSI. Checking pressure
6. You want to have the PSI on the gauge read the same as the PSI rating printed on your tire's sidewall when your tires are cold (unless noted) this is your CTP cold tire pressure. If you are checking your tires on a road trip when they are hot, expect a slightly higher reading than listed on the sidewall. Different tires wear differently so you may want to run your own "custom" pressure regardless of what is printed on the sidewall, more about that way below. Reading gauge
7. If you got a low reading you'll need to add air. We suggest buying an air compressor for this. Considering your life and ALL stang performance rides on your tires. You can also use a cheap 12volt tire air compressor, a hand pump or drive to your nearest gas station. A good air compressor will let you run air tools, blowers and impact wrenches as well. Air compressor
8. Here we are using our tire attachment on our compressor hose and adding more air to the tire. We suggest over filling it by 5 psi, then letting air out to the correct spec. This will "work out" the tire valve both ways. When you are done, check the PSI level again until it's according to spec. At this time CHECK THE SPARE TIRE and fill it up. Those small donut spares need 60 PSI (or more because of their size) and get low after 2 or 3 months of non use.
NOTE the typo in the photo, we meant "ADD" air not "air air" :-)
Addig air

Tire Leaks:

Fast loss of air pressure. If you notice this, pull over and check for bolts or nails in the tire tread, inner and outer side walls. This will usually happen on the road, so if you find a small nail or small round object in your tire, DO NOT remove it (unless it's causing more damage), it will act as a "plug" and keep air inside your tire for the moment, pull it out and you'll go flat immediately. We suggest driving to the nearest known service station "slowly" with the nail in place. If you don't know where the nearest service station is then stop the stang and use the spare tire. If you have a can of "fix a flat" you can pull the nail and try to fill the tire, remember, after pulling the nail (or ?) it will be very hard to find the hole again. Immediately have the tire fixed, never run with "fix a flat" air in your tire for more than you have to, most of these "fix a flat" air compounds are flammable.

If you "blew out" your tire then don't panic, casually hit your emergency lights and bring the stang to a nice and slow rolling stop, pulling over to the side of the road slowly while stopping. If the tire completely blew off the rim and you rolled on your bare rim for a while, you'll probably need a new rim at this point. Get out the spare, if you don't have one, call a tow truck, if you can't get to a phone, bite the bullet and drive on the bare rim (you'll completely ruin it though) or start walking. You can flag motorists down to asist you at your own risk.

Slow loss of air pressure, slow leaks. These are the most frustrating and can be caused by many things. You may have run over a small nail that pulled itself out and is now causing a leak with a small hole. Your tire valve may be leaking (or faulty) and not sealing the air properly, valves go bad like anything else. Your tire may be leaking from an area where it meets the rim. Drastic changes in weather can cause low tire pressure. Leaving your stang parked for several days / weeks without driving it can cause low tire pressure.

Finding the Leak:

There is only one real (quick) way to find slow leaks: Dunk the tire completely or partially in water.You'll need to un-bolt the tire and place it in a water tank, swimming pool, bathtub (not if your married), hot tub, etc. (make sure you clean the tire first :-). This way you can check for air bubbles. Some service stations have water tanks for this purpose to find leaks. If you can't completely dunk it, you can also spray the tire in soapy water and check for air bubbles, one section at a time.

Fixing the Tire:

If the tire has a large hole or sidewall damage, then it may be un-fixable. If it has a small hole in the tread area then it can be fixed. Once you have found the hole in the tire there are several things you can do to fix it. One common fix is a tire plug. This is a rubber cord that is stuffed into the hole with some rubber cement added to seal it. It's then cut or trimmed to tread length. Tire plugs should last for the life of the tire and at worst may develop slow leaks and have to be re-plugged. You can buy a tire plug kit for $5.00 or pay a service station a few extra bucks to do it for you.

If your tires look good but only one seems to loose air and you gave up on finding the hole and are suffering from a slow tire leak, then you may try using a can of "fix a flat" or similar. Let all the air out of the tire, then fill it up with this stuff. This stuff may seal up a tiny slow leak you can't seem to find. Follow the directions on the can to use correctly. Most require you to drive the stang a few miles to get it to the leak area. Make sure you do not leave it in the tire permanently. After this seal period let the air out of the tire and fill it up with regular compressed air. If it still leaks, then you may need to replace the valves.

How Much Air ?

The answer to this depends on your tire wear, and the season / weather. Look at the tread wear pattern on your tire. If you notice more wear in the middle of your tire, lower your pressure point when you fill your tires by 4-5 PSI. If you notice the sides of the tread wearing more, then raise the pressure point by 4-5PSI. Eventually you will know the optimum PSI rating for your particular tire based on tire wear. We call this "Optimum wear pressure" and it's based on your tires (not your friends tires, even if they are identical). The way you hit the gas and drive determines how your tires wear on your mustang.

The next thing to consider is the weather. Colder temperatures keep the PSI in the tire fairly constant. When it gets hot outside and hot on the road, your tire will expand as the pressure increases inside the tire due to heat. You may want to account for this when filling your tire (base your decision on tire wear not the pressure imprinted on the sidewall in this case). If your weather is freezing one day and 100 degrees the next day, back and forth, for a few days (like in the desert) then you'll need to check your tires often to make sure they are at optimum PSI levels.

The next thing to consider is your goal. At a drag strip, lowering the PSI in your rear tires a tad will give you better launch traction (allowing you to free up some weight in the rear as well). We're still talking normal street tires here. We'll talk slicks, snow, rain and other types of tires below.

Gas mileage is affected by tire pressure:

Worried about 4.10 gears giving you bad MPG. Your tires may be giving you a MPG problem by 1 or 2 MPG. If they are low, they create more drag. Fill them to specs imprinted on the sidewall or to your determined optimum wear pressure. By contrast, overfilled tires won't give you better MPG. Your tires will wear in the center more and you will spin them more easily on sandy roads.

When to buy a new tire:

Die hards (or rich folks) buy a new one for any hole or tire problem. We buy tires when the tread is almost gone and plug small holes. Some tires have "wear indicators" on them, they are rubber stumps located in the tire grooves. Some use a penny and place it in a tire groove, if the tread is below lincoln's hair (on his head), they replace it. If you are driving with exposed radial mesh showing and no tread, then you need to get a new tire tommorrow !

The "Donut" Spare:

It's located in your trunk next to the "joke" jack , please make sure it's got air or you are dragging it along with you for no reason. It's good for 50 miles per hour max for 50 miles (ideal), surely they can go for longer distances but they are not intended for use until you can "afford" to buy a new tire. Check for your tire lug nut wrench and lug nut key as well. If you need to jack up your stang with the OEM jack, there are special "notches" on the underside of your stang to properly secure the jack at the frame rails, there are four, one in each corner.

Armorall is good for your tire, but not everywhere:

Ask a motorcycle racer about Armorall protectant on tires :-) We do recommend Armorall (or other tire dressing) on the sidewall BUT NOT on the tread area. It can cause a loss of traction on pavement (believe it). Having it on the sidewall is good and may prevent damage to the tire when hitting a curb for example. The sidewall will "slide" rather than "bite" and tear. If you get a little on the tread no big deal, but don't "coat" the entire tread area, stick to only the sidewalls. Make sure you clean your tires regularly with a rag and cleaner before applying tire dressing. Don't just keep putting layers of tire dressing on top of crud.

Rotate them if you can:

The front tires will wear out the side of the tread area faster than the rear tires, especially with the SN95's excellent attitude changes during suspension travel up front. The rear will wear out the middle area faster than the front, especially if you burn out a lot, g-forces during burnout will throw the center of the tire out regardless of air pressure. So rotating your tires will insure proper tire wear IF... all four of your tires are the same size (like the stock tires). Remember, your Mustang tires can only rotate in one direction (for best traction) so keep the left side tires on the left and right side on the right. Rotate tires front to back only. Look in your owners manual for a rotation schedule. Folks that have larger (wider) tires in the rear get the benefit of better rear end traction and a better lateral g figure. But they can't rotate their tires.

Types of tires:

We could spend 30 pages defining this. We'll simplify. There are different type of tires available. We'll brake "street tires" into two main groups, wet and dry:

Rain / Wet traction tires:
These tires are available for rain / snow sludge type of driving and allow high confidence driving under these conditions. They have many "channels", grooves, and "fingers" to actually create a two tier standoff with the ground surface to allow water to channel through them. Potential hydroplaning is virtually eliminated. Under rain conditions, in a road race, a 3 cylinder Geo metro with rain tires will beat a Mustang GT without them, the Mustang will probably end up in a wall. That's how good "rain tires" really are. When it's dry, rain tires are a bit more "sloppy" in hard turns than dry / multi purpose tires.

Dry traction / multi purpose tires.
Many companies try to optimize their tires for dry weather with a bit of wet traction capability as well. Gatorbacks, firehawks, Comp T/A's, etc. are tires that fall into this category, offering more solid rubber on the road that's not broken up by tiny slit patterns. There are even some types of tires that put only the minimum required wet traction capability (grooves, etc.) sometimes known as "half slicks", etc. for folks that want to compromise their wet traction for all out dry traction but still be legal when driving on city streets. Many performance tires also carry a "rating", for example a "Z"rated tire is supposed to be rated up to 150MPH. H rated up to 100MPH, etc. However, we've seen $20 radials go over 100MPH no problem.

Tire rubber compounds.
There are also different tire compounds, S, C, G, F... and more. To simplify, a softer tire compound will offer you slightly better traction on hot days, but won't last as long (mileage) as a tire with a slightly harder rubber compound. Always ask a salesman about tire compounds, names vary from brand to brand.

Other tire types:

Slicks
These are tires with no-tread pattern on them at all. They are mainly used in the rear for drag racing applications. They put the full amount of rubber possible on the ground for maximum traction. They also have flexible sidewalls to account for axle windup and a larger size. These tires are made to compress during launch and expand their diameter slightly for more traction.

Run Flat Tires.
The future of tires are these. The spare tire will be a thing of the past for passenger cars as these tires make their way into distribution and their costs go down. These tires allow you to run your stang with no air whatsoever in the tire. You can go 200 miles at up to 55 MPH. The sidewalls of these tires are stiffer and these tires have a "inner tube "like double chamber design to make this possible.

Re-treads.
These are used tires that have had their treads re-done. They are usually sold for less than a new tire.

Radials.
Like "Kleenex" and "Xerox" are a name brands that became so used in daily life, "Radials" is a term that came to describe thin (normal) and standard width tires that can be used on your V8 stang (but we don't recommend it) and on most passenger cars. The 4 cylinder base Mustangs of the 80's used a radial type of tire as standard equipment. The current base stangs are using a wider tire and V8 stangs even wider, than "radial" type tires. Radial refers to the steel belted "radial" mesh wrap within the rubber compound to re-enforce the tire.

Some definitions at the tire shop they may charge installation fees for:
Balance: Making sure the tire spins balanced on each rim, weights are placed on the tire to do this.
Mounting: Actually putting the rubber onto your rims.
Valve stems: Installing the valves and stems.
Alignment: Tire alignment, don't confuse this with a camber / caster front end alignment they won't do that, rather the shop will do a font to back wheel alignment and possibly a toe in / out alignment based on your previous settings, unless it was way off beforehand like when you hit that pot hole in the road last week at 50 Mph and threw your alignment off :-)

Which are the best tires for your stang for street use ?

The best tires are the ones you can afford that fit your rims. Why? Because it's hard to find a "bad" tire from a name brand company these days. There are so many types of tires. Make your own decision or listen to someone posting on a message board. Hopefully the info here can help you make your next tire buying decision a bit easier.

We want to emphasize good tire maintenance to get top performance and safety out of your stang. We'll talk about tire widths & ratios (P300's, etc.) when we talk about Rims in another article.

Til next time... See ya on the street !


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