Campaign for the right tyre pressure
3 steps to achieving optimum tyre pressure
Try it, and make sure you’re working with the right tyre pressure
Here is how you go about determining your optimal tyre pressures:
1. Establish your tractor’s wheel load
• by weighing each axle when fitted with different attachments and weights or
• by estimating it (inside this brochure you will find a guide to estimating the wheel load)
2. Take the appropriate tyre pressure values for the required speed from the Technical Data Book.
Get the tyre pressure
right – and keep
the ground breathing!
3.Enter the respective values on the sticker enclosed. Ensure that this sticker is placed in a clearly visibly position on your
tractor and then you can always double-check your tyre pressure values.
3 easy steps to achieving optimum tyre pressure
Under the sticker there is an application example
Enter the details of your
tractor tyres, the equipment
attached and the optimum
tyre pressure for the front
axle (FA) and rear axle (RA)
when driving on the road and
in the field – as shown here.
Tractor tyres
Front axle:
Mitas
Rear axle:
Mitas
540 / 65R 28 RD 0 3
650 / 65R 38 RD 0 3
50
Attached equipment/application
Road . . . . . . . km/h
FA (bar) RA (bar)
Field 10 km/h
FA (bar) RA (bar)
Seed drilling set-up
1.6 1.6 0.6 0.6
www-mitas-tyres.com
If you have any questions about tyrepressure settings, we’re here to help you
The estimation rules given in this brochure are for information only. To the extent permitted by law, no warranty, express or implied,
and no liability in connection with the use of the information is contained in this publication. There is no liability for any direct, indirect,
incidental, consequential or punitive damages arising out of the use of this publication.
MITAS a.s.
Švehlova 1900, 106 25 Praha 10, Czech Republic
Technical support hotline: 267 111 594, 577 523 437 (482)
business@mitas-tyres.com, www.mitas-tyres.com
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Campaign for the right tyre pressure
The best possible tyre pressure
in the field and on the road
With the right tyre pressure in the field and on the road, you can optimise the traction on your tractor, reduce your diesel
costs and protect the ground structure!
Driving in the field
with reduced tyre pressure
Driving on the road
with increased tyre pressure
The following two examples illustrate the factors mentioned that affect the wheel load and help in the estimation:
Example A
Example B
Tractor 150 HP-class, with additional
weights – road application
Tractor 150 HP-class, with additional
weights – field application
Max. weight allowed: 10 000 kg
Tyre sizes: front axle (FA) Mitas 540/65 R 28 RD-03;
rear axle (RA) Mitas 650/65 R 38 RD-03
Max. weight allowed: 10 000 kg
Tyre sizes: front axle (FA) Mitas 540/65 R 28 RD-03;
rear axle (RA) Mitas 650/65 R 38 RD-03
Tractor with add. weights
=
9 900 kg
Tractor with add. weights
=
FA load (18 %)
=
1 830 kg
FA load (37 %)
=
3 043 kg
Large ground contact patch
per front wheel
=
915 kg
per front wheel
=
1 522 kg
• R
educes slip and in turn diesel
consumption by up to 20 %
RA load (82 %)
=
8 070 kg
RA load (63 %)
=
5 157 kg
per rear wheel
=
4 035 kg
per rear wheel
=
2 579 kg
Tractor with weight (empty)
=
6 500 kg
Tractor with weight (empty)
=
6 500 kg
FA load (40 %)
=
2 600 kg
FA load (40 %)
=
2 600 kg
RA load (60 %)
=
3 900 kg
RA load (82 %)
=
3 900 kg
Tyre pressure
Reduced ground pressure
• P
rotects the ground structure, thereby
increasing return per hectare
Shallow rut depth
• S
aves up to 10 % on fuel per centimetre
of rut depth
• Avoids elaborate soil loosening work
Tyre pressure
Improved steering, tipping and
braking stability
• Increases driving safety
Reduced rolling resistance
• C
uts diesel consumption
Even wear
Add. front weight
(FW) 800 kg
Add. rear weight
(RW) 2 600 kg
2.8 m (W)
Add. front weight
(FW) 800 kg
2.0 m (R)
1.0 m (F)
Distance FW to front axle (F) = 1.0 m; Wheel base (W) = 2.8 m;
Distance RW to rear axle (R) = 2.0 m
Calculation for the front tyre load:
Front axle load
with weight
= 2 600 kg − 2.0 ⁄ 2.8 m × 2 600 kg + (1.0 m ⁄ 2.8 m + 1) × 800 kg
= 2 600 kg − 1 857 kg + 1 086 kg
= 1 829 kg (= front axle load) ⁄ 2 = wheel load
Front wheel load = 915 kg
Please read the corresponding inflation pressure for the calculated wheel load
(915 kg) and depending on the speed from the technical data book.
Calculation for the rear tyre load:
Rear axle load
with weigh = 3 900 kg + (2.0 m ⁄ 2.8 m + 1) × 2 600 kg − 1.0 m ⁄ 2.8 m × 800 kg
= 3 900 kg + 4 457 kg − 286 kg
= 8 071 kg (= rear axle load) ⁄ 2 = wheel load
Rear wheel load = 4 035 kg
If you have no weighing facilities nearby, you can also just estimate the wheel load.
To do this, you have to allow for the following factors:
Please read the corresponding inflation pressure for the calculated wheel load
(4 035 kg) and depending on the speed from the technical data book.
Tyre pressure 1.6 bar
Tyre
size
650/65
R 38
Service
description LI/SS
157 D
(160 A8)
Rim
(permitted)
W 18 L
DW 20 A
Section
width
(mm)
626
646
Outer
diameter
(mm)
1 829
Wheel load 4 035 kg
Tyre pressure
Speed
(km/h)
0.6
0.8
1.0
1.2
1.4
1.6
2 740
2 880
3 505
2 985
3 110
3 270
3 980
3 155
3 315
3 455
3 630
4 420
3 450
3 625
3 780
3 970
4 830
3 790
3 980
4 150
4 360
5 310
4 125
4 330
4 500
4 745
5 775
2.0
6 775
2.8 m (W)
2.0 m (R)
For field use with continued high torque, e. g. ploughing,
the values for 30 km/h (18 mph) apply.
Formula for calculation of front and rear axle weights:
Front axle weight with ballast = FAL empty − R ⁄ W × RW + (F ⁄ W + 1) × FW
Rear axle weight with ballast = RAL empty + (R ⁄ W + 1) × RW − F ⁄ W × FW
ttached weight, tongue weight
A
Variable weights (full or empty tank / hopper)
Leverage / Overhang
Dynamic loads in driving operation (rocking on the road)
RW = 2 600kg,
thereof ca. 1/3
as remaining axle
weight (= 900 kg)
• Increases mileage performance
1.0 m (F)
•
•
•
•
8 200 kg
Speed
65
50
40
30
10
For field application (without high and sustained torque)
the 10 km/h values apply, which in this case would lead to the lowest possible:
Tyre pressure 0.6 bar
Tyre
size
650/65
R 38
Service
description LI/SS
157 D
(160 A8)
Rim
(permitted)
W 18 L
DW 20 A
Section
width
(mm)
626
646
Outer
diameter
(mm)
1 829
Wheel load 2 579 kg
Tyre pressure
Speed
(km/h)
0.6
0.8
1.0
1.2
1.4
1.6
2 740
2 880
3 505
2 985
3 110
3 270
3 980
3 155
3 315
3 455
3 630
4 420
3 450
3 625
3 780
3 970
4 830
3 790
3 980
4 150
4 360
5 310
4 125
4 330
4 500
4 745
5 775
2.0
6 775
65
50
40
Speed
30
10
This example of field use shows optimum ballast distribution on front and rear axle.
However, if the centre of gravity of the rear weight is shifted towards the back, this
takes the load off the front axle and traction here is lost.