DRIVER EDUCATION
STUDENT LEARNING PLAN #13
TIRE SELECTION AND CARE
Tires have as much to do
with the safe performance of your car as the brakes, steering, and suspension
system. If you give them proper care, they
can increase your pleasure in driving and save you money. These lessons will help you provide the care
necessary for safety, maximum tire life and performance. They can also help you select tires to match
the car, the load, and your particular needs.
April, 1976
Car owners have the responsibility
for proper tire care and selection.
SUPPORTING IDEAS
1.
Tires should
be selected to match the car and driver needs.
2.
Proper care
of tires improves performance and save money.
3.
Regular
inspection of tire wear and inflation is important to tire care.
UNIT 13 - - TIRE SELECTION AND CARE
LESSON IDEAS.
1.
Tires should
be selected to match the drivers needs.
2.
Proper care
of tires improves performance and saves money.
3.
Regular
inspection of tire wear and inflation is important to tire care.
1.
You can list
the basic tire types and tell advantages and disadvantages of each.
2.
You can list
the types of fibers used in tires and identify the advantages and disadvantages
of each.
3.
Given a
description of tire wear, you can identify the possible causes.
4.
You can list
at least 4 preventative maintenance procedures for longer tire life.
5.
You can
describe the proper way to determine tire inflation.
6.
You can
identify various tire rotation patterns and identify the types of tires they
are for and what purposes rotation serves.
1.
Read “Tire
Selection.” Write out the answers to the
study questions.
2.
Make a chart
of tire types and their characteristics.
3.
Tell what
tire (type and fiber) you would buy.
Explain why you think it is best for you.
4.
Discuss with
your parents the next set of tires they are going to buy. Find out their reasons for their choice.
5.
Explain what
is meant by “mixing” tires. Why should
it be avoided?
6.
Read “Tire
Care.” Write out the answers to study
questions.
7.
Find
pictures in a book or magazine that show various tire wear to see if they are wearing
properly and have enough tread.
8.
Make a list
of problems related to improper tire pressure.
9.
Check tire
pressure on driver’s ed. Car and/or family car.
Find out the recommended pressure and determine if tires are over, under
or properly inflated for city driving and for expressway driving.
The tire
diagrams above depict (top row) various erratic wear patterns and in each
instance directly underneath, the cause of the problem as well as the
corrective adjustment required. The tire
flaw may be something as simple to fix as underinflation
or overinflation of the tire, in which case the owner
can attend to it. If the trouble is
caused by improper balancing or on the front wheels, by misalignment, the car
should he taken as soon as possible to a shop that specializes in doing this
kind or work. A program of personal
inspections and prompt correction of any flaws will ensure longer tire life.
Tread wear indicators (above) are smooth
horizontal bands about half an inch wide that become visible when only 1/16 of
an inch remains of the original tread.
When the bands appear two or more adjacent grooves, replace the tire.
TIRE SELECTION
Buying tires is often the hardest
part of maintenance for owners. Not only
are there three types of tires and many manufacturers, but each brand ahas
several grades.
You should replace
tires with tires of the same size or one that is like it. Putting a different size on your car may
cause the speedometer to be wrong or cause poor performance.
Plan what type of
tire to buy, by thinking of the type of driving you do. Each of the three types of tires have good
and bad points. Choose the tire that
fits your driving needs.
Bias or bias
ply tires are made with crisscrossed layers of cords. This makes for rigid sidewalls and
treads. They are good for driving
around town and can take curb bumping.
There are few manufacturing problems.
They give the softest ride of the three tire types. The problem with these tires is that they are
poor for fast driving (highway) and gard turning.
Bias belted
tires are made like bias tires but two or more layers of “belts” are added
under the tread. Bias belted tires are good
for cross country driving.
They also give better stability, handle better, and are less likely to
be bruised, punctured, or cut. They
should last 15 to 50 percent longer than bias tires. Another fringe benefit is 2 to 5 percent more
gas mileage.
Radial tires
are the newest tires on the market. The
cords run from side to side on the tire.
Belts are added running with the tread.
The tread of these tires goes slightly to the side. The design makes a tire look underinflated
even when properly inflated. They are
best for all around driving and offer the best handling points as the tread is
kept flatter on the road and in curves.
They get less damage from bad roads that have ruts, rocks, and road
debris. They increase gas mileage and
some offer a guarantee of 40,000 miles.
Some of their bad
points are they cost a lot, and give a harsh ride at low speeds. They are also easily bruised by hitting
curbs. They should never be mixed
with other tires.
Besides picking the
tire type, you often have a choice of cord fabric. Radial tires often are steel belted. Other fabrics used are rayon, nylon,
polyester, and fiberglass. Rayon gives
the softest ride and is the cheapest but may be hurt by much exposure to
water. Nylon is stronger than rayon but
may give a rough ride and have temporary flat spots when the car sits. Polyester gives a good ride and good
performance but is not as strong as nylon.
Fiberglass may be added for more strength and better mileage. Steel gives maximum tread wear and good traction. It is the strongest cord used.
Some people, trying
to save money, think about using retreads.
These are worn tires with new treads added. Unless well done, they are difficult or
impossible to balance. Also, they should
not be used for high speed highway driving.
For winter driving,
many people choose to buy special snow tires.
These tires have special treads which grip the snow and are
self-cleaning. Snow tires wear faster
than normal tires on dry pavement and are not made for fast highway driving. Be sure to check the manufacturer’s
recommendations before buying tires.
Studded tires have
small metal cleats in the tread to dig into snow and ice for better
traction. Many states including
When buying
replacement tires, it is best to buy a whole set (4 or 5 tires). It is best to have the same type of tire with
the same handling characteristics which means better vehicle control. If you find you don’t really need four tires,
buy two tires of the same type already on your car and mount them on the rear
axle. (The best tires would be in the
rear to cut skid potential.) It is very
dangerous to mix radial tires with other types.
Safe driving requires that you can count on good performance under all
conditions. When bias, bias belted, and
radial tires are mixed some control is lost, especially in crnering. It is like wearing one rubber and one leather
soled shoe. You probably won’t notice
the difference until it’s too late.
In order to pick the
proper tire, you must ask yourself some questions.
1.
What type of
driving will I be doing?
2.
Do I need
winter tires for the driving I do?
3.
How much can
I afford to spend?
4.
How many more
miles do I plan on driving before selling the car?
5.
What brand
of tire is best?
6.
Can I wait
for sales?
7.
Can I get
the same tire cheaper somewhere else?
Remember, the smart
shopper thinks of his/her needs, the price and the cost per mile. Be a comparison shopper.
1.
Should you
mix tire types? Explain.
2.
What are the
good and bad points of bias tires? Bias
belted? Radial?
TIRE CARE
The tires of
your car are very important to your safety and have a direct effect on your
budget. Well-cared-for tires will last
longer and give better gas mileage. Your
car will start, stop, and turn better.
Most tire care consists of simple things that anyone can do. You should be sure that all valves have caps
and the stones, nails, and glass that become lodged in the treads of the tire
are removed. Avoid hitting the tires in
oil deposits. Remember that high speeds,
fast starts, and pressure drops very low suspect a leak, bent rim, or cracked
valve. Be sure to check the pressure of
the tire again within a few hours to be sure the pressure is holding.
Tire pressure is often given in terms of KPA (kilopascal) or simply
“pounds.” The correct pressure for your
tires can be found in the owner’s manual or the glove compartment of your car. If you buy different replacement tires, be
sure to find out from the dealer the proper pressure when you check your tires.
Most tire charts in cars and owner’s manuals will tell two different
pressures. One is for a light load (one
to five passengers and total weight not more than 240 kg and the other for full
load (up to 500 kg). If you plan larger
loads than those given on the chart you should think of buying different tires
and maybe buying helper springs or heavy duty shock absorbers. Check charts for the maximum weight per tire
for the inflation you will be using. The
total weight should not be more than the weight of the car and its load
together.
Tire pressure should be checked about once a month. This may vary from two to six weeds. Also, tire pressure should be checked before
long trips and after extreme temperature changes. It is thought that your tire pressure will
change one pound for each ten degree change in temperature. (If it is 32 degrees celsius
one day and 13kp the next, your tire pressure will go down about five
pounds.) Tire pressure is always given
as a “cold tire pressure.” All tires
will increase pressure while driving so it is important to check the pressure
before driving. Of you must drive to a
gas station, go right there. After
driving, wait as least three hours before checking tire pressure. Do not mix up the recommended pressure
for the maximum pressure stated on the tire.
The pressure should never go above the amount stamped on the tire
and in most cases will be below it.
Although an important part of care and safety, tire pressure is often
forgotten or left in the hands of gas station attendants. Cars can have a two to ten pound difference
between the front and rear tires to give the car more stability. Attendants often put the same pressure in all
tires. Many stations use air gauges
mounted on the air hose. These air
gauges are often not right. Be sure the
station attendant uses a hand pressure gauge and knows the correct pressure for
your tires. This is really such an easy
part of maintenance that each person do it and not take chances on faulty
equipment or poorly informed service attendants. Also, attendants forget to check the spare
tire pressure. It should be checked at
the same time.
A mistake people often make is to check tire pressure after driving. It
is impossible to figure how much pressure will be increased while driving. Letting air out of a “hot” tire may cause underinflation.
Another mistake is the “visual check.” Visual checks should be used to
find a flat tire, check for stones or cuts; but cannot be used to get correct
pressure.
Bias and bias belted tires may be ten pounds below pressure before they
“look low.” On the other hand, radial
tires, when properly inflated, “look low.”
The only way to get the right idea of the tire pressure is with a
pressure gauge.
Improper inflation makes problems in vehicle control. One low tire may cause a pull on the steering
wheel or affect the cornering ability of the car. Both overinflated and underinflated tires are
more likely to suffer a blowout.
Traction is cut which lengthens stopping distance and cuts cornering
skill. Also, tires will wear improperly. Overinflated tires get rounder and wear in
the center. Underinflated tires bulge
and wear on the edges. Other things that
will cause your tires to wear improperly and quickly include improper wheel
balance and alignment.
Although you are warned not to change tire pressure when driving in
snow it is important to fix it for long distance highway driving. Depending on the load and type of pressure
marked on the side of your tires.
Tread depths tell how well your car will handle, so you should check
tread life and replace them when they are bad.
Experts say that treads must be at least 1.65 mm. Cheap gauges can be used to measure tread
depth and the evenness of wear in tires.
A simple test anyone can use is the “penny test.” Insert a penny head first into the tread. If the head is totally visible, it is time to
replace the tires. Remember, bald and nearly
bald tires are more likely to be punctured, more likely to blowout, and more
likely to hydroplane in wet weather.
Tires on a car do not wear evenly.
Back tires get more wear than the front.
In order to balance wear and make handling better, tires should be
rotated every 9600 km – 12,800 km. The
best tire rotation is shown on the following page. Please see the radial tires have a different
rotation than all other tires.
Five tire rotation is often used with a new car. Often, when people buy the second set of
tires they keep the best for a spare and only the four new tires are
rotated. If you buy special winter tires
while changing back to your regular tires.
Snow tires may be bought for the back of the car only or for all four
wheels. This means that you will also
have to store the “extra” tires. Tires
should be stored in a cool dry place away from furnaces r batteries which may
produce ozone. Store whitewalls facing
each other. Identify which wheel
position they were taken off of so they can be returned to the proper
position. Like most new things, tires
need a break-in period. Tires should be
driven below 90km/h for the first 80 km.
1.
List five
general maintenance tips for tires.
2.
How often
should tire pressures be checked? Spare
tire?
3.
Explain
“cold” tire pressure.
4.
What can
tire wear patterns tell you?
5.
What is the
minimum safe tire tread depth?
6.
How often
should tires be rotated and why?
7.
Where is the
correct air pressure generally found?
8.
What is the purpose
if “visual” tire checks?
9.
What
adjustments should be made in tire pressure for high speed driving?
TWO PLY TIRE CONTRUCTION
TIRE CAR AND SELECTION TEST
Multiple
Choice Questions - - Select the ONE best answer.
1.
A tire that
is driven without enough air (underinflated) will wear
A.
on the
inside edge.
B.
on the
outside edge.
C.
on both
edges.
D.
in the
center.
2.
Tires will
wear out faster if your driving usually includes
A.
gradual
stops.
B.
quick stops.
C.
low speeds
3.
Your tires
may be damaged by
A.
hitting
curbs when parking.
B.
parking in
oil deposits.
C.
both of
these.
4.
The correct
tire pressure for your tires is usually
A.
found in the
glove department.
B.
known by a
gas station attendant.
C.
on the tire
sidewall.
5.
Tire
pressure should be checked
A.
only when
tires look low.
B.
every week.
C.
once a
month.
D.
twice a
year.
6.
The spare
tire pressure should be checked
A.
every week.
B.
once a
month.
C.
twice a
year.
D.
once a year.
7.
Identify the
false statement about tire pressure
A.
Tire
pressure should be checked before driving.
B.
Tire pressure
should be lowered in the winter.
C.
Tire
pressure should be raised for heavy loads
D.
Hand gauges
are usually the most accurate.
8.
Underinflated
tires
A.
shorten
stopping distance.
B.
increase
turning ability.
C.
increase
chances of a blowout.
D.
none of
these.
9.
Overinflated
tires
A.
wear out in
the center.
B.
are better
for highway driving.
C.
make better
stops.
D.
all of
these.
10.
Tires with
poor treads
A.
are more
likely to hydroplane.
B.
are more
likely to be punctured.
C.
take longer
to stop.
D.
all of
these.
11.
Tires are no
longer considered safe when the tread is
A.
0.8 mm
B.
1.6 mm
C.
3.2 mm
D.
6.4 mm
12.
Tires should
be rotated every
A.
3,200 km
B.
6,400 – 8,
000 km
C.
9,600 – 12,
900 km
D.
16,000 km
13.
Tire
rotation is done to
A.
equalize the
wear on all tires.
B.
improve the
handling of the car.
C.
keep the
best tires on the back.
D.
all of
these.
14.
In the tire
size B70- 13, the number 13 stands for the
A.
diameter of
the rim.
B.
width of the
tire.
C.
height-to
width ratio.
15.
Bias tires
are good for
A.
driving
around town.
B.
cross
country driving.
C.
decrease gas
consumption.
D.
all of
these.
16.
Bias belted
tires are
A.
stronger
than radial tires.
B.
stronger
than bias tires.
C.
Usually
guaranteed for 64,000 km
17.
Radial tires
A.
are the
cheapest types of tires to buy.
B.
Give the
softest ride.
C.
Offer the
best handling charecteristics.
18.
A disadvantage
of many snow tires is that they
A.
should not
be used for highway driving.
B.
Make
stopping distance longer.
C.
Are legal in
some states.
D.
All of these
19. Studded tires
A.
should not
be rotated.
B.
Are designed
for highway driving.
C.
Are illegal
in
20. When buying new tires,
it is best to buy
A.
one tire at
a time (as they are needed).
B.
Two at a
tome (placed on the rear axle).
C.
A full set
(four or five tires).
21.
When buying
winter tires for the back axle only, they
A.
should be
the same type of tires as the front tires.
B.
Should be
better type of tire than the front.
C.
May be any
type pf tires.
22.
When buying
new tires, you should consider
A.
the number
of kilometers you plan to drive the car.
B.
the type of
driving you do.
C.
If one brand
is better than the other.
23. When changing a flat
tire, the car should
A.
be in park.
B.
Have
four-way flashers on (hazard lights).
C.
Be well off
the road.
D.
All of
these.
24. When changing a tire, it
is wise to
A.
tighten the
lug nuts completely before lowering the car
B.
use a star
pattern when tightening the lug nuts.
C.
Loosen all
lug nuts completely before raising the car.
D.
All of
these.
TEACHER’S GUIDE FOR TIRES UNIT
This unit is designed
to assist students in the development of stored information for proper tire
care and selection. The purpose is to
show students how to make their safer at the lowest cost to them. As in maintenance of any part of the car,
lack of knowledge or simple failure to exercise one’s knowledge may lead to
personal inconvenience, higher operating costs, accidents, or even personal
injury. Today’s tires are much safer
than yesterday’s, but proper maintenance and selection is still necessary.
Much of the material
presented in this unit cannot really be tested except in an objective manner in
the classroom. It is hoped, however,
that whenever time and facilities permit that students will be given the
opportunity in classroom, range, or even possibly stimulation, to participate
in check tread depth, tread wear patterns, and tire pressure as well as learn
how to change a flat. This laboratory
experience may be completed with other units including such items as battery
and oil checks. Although tread wear
patterns are discussed in this unit only in relation to proper inflation, it is
assumed that it would be covered in other units under system malfunctions.
Since tires change
rapidly, no effort was made to evaluate brands of tires. It hoped that you and your students will have
available the most current library materials on tire selection and care. Those references should be used and
recommended to students for their future use.
The material presented here is based on the general claims of the tire
industry. Encourage students to look for
the exceptions.
Every attempt has been made to test
each objective outlined in the student learning plan. Each answer can be found in one of the two
student resource papers included.
1.
C 6. B 11. B 16. B 21. A
2.
B 7. B 12. C 17. C 22. D
3.
C 8. C 13. D 18. A 23. D
4.
A 9. A 14. A 19. A 24. B
5.
C 10. D 15. A 20. C
1.
Student
Learning Plan.
2.
Tire Care.
3.
Tire
Selection.
4.
New Car
Owner’s Manual
5.
Consumer
Tire Guide, (available free from:
Tire Industry Safety Council,
1.
Brochures from
local dealers.
2.
Consumer
Reports Consumers’ Research Yearbooks, and current
monthly issues.