Armor protects your vehicle from damage. It works in two ways: an armor part protects the parts behind it by taking damage, until it is destroyed; and each piece of armor adds its durability points to your vehicle's overall durability value (which is based on your cabin's durability points). Your vehicle's total is the value shown on your heads-up display.
You gain armor parts by leveling up with the various factions. The different factions have parts with different characteristics: the parts supplied by the Lunatics have the best durability-to-mass (D/M) ratio and worst durability-to-powerscore (D/PS) ratio, while the Scavengers have the best D/PS ratio and worst D/M ratio. The Engineers and Nomads ratios are between these two. Steppenwolfs armor has the highest absolute armor value but it loses a little in D/PS ratio to the Scavengers and a lot in D/M ratio to the Lunatics.
Engineer Armor
Name
Durability
Power
Weight
D/W
D/P
Canvas roof
60
53
135
0.444444444
1.132075471
Fender
25
22
56
0.446428571
1.136363636
Medium strut
13
11
28
0.464285714
1.181818181
Minivan sideboard
25
22
56
0.446428571
1.136363636
Rear door
86
77
196
0.438775510
1.116883116
Running board
15
13
34
0.441176470
1.153846153
Small strut
6
4
12
0.50000000
1.500000000
Torino bonnet
94
84
213
0.441214553
1.119047619
Torino fender
25
22
56
0.446428571
1.136363636
Torino nosecut
40
35
90
0.444444444
1.142857142
Torino rear
25
22
56
0.446428571
1.136363636
Van ramp
6
4
12
0.50000000
1.500000000
Van side
20
18
45
0.444444444
1.1111111111
Van window
23
20
51
0.450980392
1.150000000
Gun mount
38
133
43
0.883720930
0.285714285
Bumper 'Catch'
54
26
74
0.729729729
2.076923076
Radiator grille
7
7
21
0.333333333
1.000000000
Hatchet
40
24
60
0.666666666
1.666666666
Small buggy floor
8
28
9
0.888888888
0.285714285
Offroader bumper
72
42
109
0.660550458
1.714285714
Buggy engine cover
5
14
5
1.000000000
0.357142857
Buggy trunk
8
28
9
0.888888888
0.285714285
Lunatic Armor
Name
Durability
Power
Weight
D/W
D/P
Buggy fender left
6
7
11
0.545454545
0.857142857
Buggy fender right
6
7
11
0.545454545
0.857142857
Left crutch
10
12
19
0.526315789
0.833333333
Right crutch
10
12
19
0.526315789
0.833333333
Fryer
28
35
54
0.518518518
0.800000000
Dryer
10
12
19
0.526315789
0.833333333
Buggy rear
44
56
86
0.511627906
0.785714285
Whaleback
41
52
80
0.512500000
0.788461538
Comb
4
4
7
0.571425714
1.000000000
Grater
6
7
11
0.545454545
0.857142857
Buggy step plate
8
9
14
0.571428571
0.888888888
Bullbar
75
44
113
0.663716814
1.704545454
Brazier
14
18
27
0.518518518
0.777777777
Frontal Protection System
54
32
78
0.692307692
1.687500000
Buggy bumper
64
36
80
0.800000000
1.777777777
Bumper Spike
58
34
82
0.707317073
1.705882352
Nomad Armor
Name
Durability
Power
Weight
D/W
D/P
Avia double slope
50
53
130
0,384615385
0,943396226
Avia panel
21
22
54
0,388888889
0,954545455
Avia panel large
42
44
108
0,388888889
0,954545455
Avia slope
9
10
24
0,375000000
0,900000000
Avia strut
7
7
19
0,368421053
1,000000000
Avia wide slope
18
20
48
0,375000000
0,900000000
Left avia fender
49
52
128
0,382812500
0,942307692
Narrow wing
47
50
121
0,388429752
0,940000000
Oblique slope
17
17
43
0,395348837
1,000000000
Oblique slope wide
33
35
85
0,388235294
0,942857143
Oblique strut
11
12
29
0,379310345
0,916666667
Plane nose
12
12
30
0,400000000
1,000000000
Right avia fender
49
52
128
0,382812500
0,942307692
Scavengers Armor
Name
Durability
Power
Weight
D/W
D/P
Barrel quarter
11
9
43
0,255813953
1,222222222
Curved pipe
8
6
31
0,258064516
1,333333333
Half wall
57
44
216
0,263888889
1,295454545
Large fender
92
72
350
0,262857143
1,277777778
Large slope
36
28
135
0,266666667
1,285714286
Long pipe shield
43
33
162
0,265432099
1,303030303
Pipe shield
29
22
108
0,268518519
1,318181818
Quater wall
29
22
108
0,268518519
1,318181818
Straight pipe
14
11
54
0,259259259
1,272727273
Thick pipe mudguard
23
18
88
0,261363636
1,277777778
T-pipe
7
6
27
0,259259259
1,166666667
Truck door
114
88
430
0,265116279
1,295454545
Truck slope
11
8
41
0,268292683
1,375000000
Twin slope
22
17
81
0,271604938
1,294117647
Wide slope
22
17
81
0,271604938
1,294117647
Steppenwolfs Armor
Name
Durability
Power
Weight
D/W
D/P
APC panel 1
100
88
377
0,265251989
1,136363636
APC panel 2
50
44
189
0,264550265
1,136363636
Armored slope
19
17
71
0,267605634
1,117647059
Armored triple slope
19
17
71
0,267605634
1,117647059
Gun tower
83
72
308
0,269480519
1,152777778
Hard module
79
69
294
0,268707483
1,144927536
Strengthened slope
41
36
154
0,266233766
1,138888889
Strengthened ventilated slope
19
17
71
0,267605634
1,117647059
Strike plate 1
88
77
330
0,266666667
1,142857143
Strike plate 2
44
39
165
0,266666667
1,128205128
Strike plate 3
38
33
142
0,267605634
1,151515152
Thin strike plate
7
6
24
0,291666667
1,166666667
Dawn's Children Armor
Name
Durability
Power
Weight
D/W
D/P
Cooling System
61
55
157
0.388535
1.10909
Ventilation Box
28
25
71
0.394366
1.12
Observation Pod
31
28
79
0.392405
1.10714
Hull Part
10
8
28
0.357142
1.25
Hull Back
52
47
134
0.388059
1.10638
Control Module
28
25
71
0.394366
1.12
Broken Radiator
19
17
48
0.395833
1.11764
Air Intake
4
3
8
0.5
1.33333
Notes
At this time, it seems that the various types of armor pieces within the game don't vary, regarding which types protect better; that is, one piece of armor will sustain the same amount of damage as any other piece which has the same number of structure points, regardless of what is causing the damage. The more layers you can apply to guard your vehicle's cabin and its other most-important parts, the better. Your vehicle will last longer on the battlefield if it has more layers of armor, as the enemy must destroy the layers one by one, to get a chance to damage your cabin. You can even apply your armor so that a layer or two covers your wheels, so it becomes more difficult for your opponent to destroy your wheels and render you immobile—it is fatal to become stationary on the battlefield. Protect your weapons with armor, too, but you must guard them without impeding their movement and operation. If you place a large piece of armor directly beside a weapon, then the weapon will not be able to rotate. This will give you a "blind spot" where your enemy can sit in safety, and attack you with impunity. While you are in your garage, experiment with different ways to arrange your weapons and armor, so that they work together well. The more often you use the Test Drive option and spawn enemy bot vehicles to face in simulated battle, the more you will learn about the strong points and weaknesses of your vehicle's configuration. It's better to invest time in practice combat, and discover the flaws in your vehicle's design when the stakes are low, than to be taken by surprise when the combat is for real.