How to Choose Servos for RC Planes and Cars
Match the servo to the job by torque, speed, size, and gear material. A 9g micro servo suits a small foam plane, while a standard servo with 9.4 kg/cm of torque suits a 1/10 car steering job. Metal gears last longer under load than plastic gears. The TowerPro SG92R costs $8.00 and gives 2.5 kg/cm of torque at 4.8V.
Quick facts
| Fact | Value |
|---|---|
| Servo signal | 50 Hz PWM, 1 to 2 ms pulse |
| SG92R torque | 2.5 kg/cm at 4.8V |
| SG92R speed | 0.1 sec per 60 degrees at 4.8V |
| MG996R torque | 9.4 kg/cm at 4.8V, 11 kg/cm at 6V |
| 1250MG torque | 3.5 kg/cm at 6.0V |
| Lowest price servo here | $8.00 for the SG92R and MA-90 |
What torque does your plane or car need?
Torque is the turning force of the servo, measured in kg/cm. A higher number moves a larger control surface or a heavier steering load.
A small foam plane flies fine on 0.6 kg/cm from a 5g SG50 servo. A 1/10 car needs 9.4 kg/cm or more for steering under load.
Check the servo datasheet for torque at your battery voltage. The MG996R gives 9.4 kg/cm at 4.8V and 11 kg/cm at 6V.
Should you pick metal gears or plastic gears?
Metal gears handle shock loads and last longer in cars and 3D planes. Plastic gears run quieter and cost less in light foam models.
The MG90D uses metal gears in a 13g digital micro servo. The SG92R uses plastic composite gears and still gives 2.5 kg/cm at 4.8V.
Pick metal gears when the servo drives steering or a large surface. Pick plastic gears for a light park flyer with small loads.
What is the difference between analog and digital servos?
An analog servo updates its position about 50 times per second. A digital servo updates faster and holds position with more force.
Digital servos suit fast steering and 3D flight where holding torque matters. The DSM-44 is digital, gives 1.6 kg/cm, and moves in 0.07 sec.
Analog servos cost less and suit trainers and slow scale models. The ES08MA set gives four analog metal gear servos for $35.00.
How do you size a servo for a plane or a car?
Measure the servo bay before you order any servo. A micro servo measures about 23 by 12 by 29 mm, while a standard servo measures about 41 by 20 by 37 mm.
Match the spline count to your servo arms. Most servos in this guide use a 25 tooth spline, so check the arm listing first.
Match the voltage too. Most micro servos run on 4.8V to 6V, so a 2 cell receiver pack needs a regulator or a high voltage servo.
How do you test a servo before you install it?
Center the servo with a tester before you fit the arm. A servo tester checks travel and centering on the bench.
Power the servo from a 4.8V to 6V source, never from a bare USB port. A servo can draw 1400mA at stall, per the MG996R datasheet.
Move the arm through its full travel and listen for binding. A servo that buzzes at the end point needs its travel reduced.
How the options compare
| Servo | Torque | Speed | Gears | Price |
|---|---|---|---|---|
| SG92R | 2.5 kg/cm at 4.8V | 0.1 sec per 60 deg at 4.8V | Plastic composite | $8.00 |
| MA-90 | 1.3 kg/cm | 0.10 sec per 60 deg at 4.8V | Metal | $8.00 |
| SG50 | 0.6 kg/cm | 0.1 sec | Not listed | $9.00 |
| MG90D | Not listed | Not listed | Metal, digital | $14.00 |
| 1250MG | 3.5 kg/cm at 6.0V | 0.14 sec | Metal | $18.00 |
| DSM-44 | 1.6 kg/cm | 0.07 sec | Metal, digital | $22.00 |
| ES08MA, set of 4 | Not listed | Not listed | Metal, analog | $35.00 |
How do you install a servo in a plane or car?
- Center the servo with a tester, then fit the arm at 90 degrees.
- Mount the servo with its screws and rubber grommets.
- Connect the servo lead to the correct receiver channel.
- Power the receiver and check full travel in both directions.
- Set the end points so the arm never binds at full throw.
Parts that fit this guide
In-stock parts ship from the New York, USA warehouse in 1-2 business days. Prices below are the live store prices we verified on November 10, 2026.
SG92R Analog Plastic Composite Gear Micro Servo ($8.00)
Micro servo at $8.00. It gives 2.5 kg/cm of torque at 4.8V with plastic composite gears.
MA-90 Metal Gear Micro Servo ($8.00)
Metal gear micro servo at $8.00. It gives 1.3 kg/cm of torque and moves in 0.10 sec per 60 degrees at 4.8V.
SG50 5g Micro Servo ($9.00)
Light 5g micro servo at $9.00. It gives 0.6 kg/cm of torque and moves in 0.1 sec.
MG90D Digital Metal Gear Micro Servo ($14.00)
Digital metal gear micro servo at $14.00. It weighs 13g and suits larger park flyers.
1250MG Metal Gear 25g Mini Servo ($18.00)
Mini servo at $18.00. It gives 3.5 kg/cm of torque at 6.0V and weighs 25g.
DSM-44 Digital Metal Gear Micro Servo ($22.00)
Digital metal gear micro servo at $22.00. It gives 1.6 kg/cm and moves in 0.07 sec.
Shop the full range: Servos at Quality RC Parts. See also: Related guide.
Frequently asked questions
What size servo does a 1/10 RC car need?
A standard servo with at least 9.4 kg/cm of torque at 4.8V. The MG996R meets that figure and costs $15.99.
Can a micro servo steer an RC car?
Yes, on a small 1/16 or 1/18 car. A 1/10 car needs a standard servo with higher torque.
Do metal gear servos last longer than plastic gear servos?
Yes, under shock loads such as steering hits and hard landings. Plastic gears suit light foam planes with small loads.
What voltage do most micro servos use?
Most run on 4.8V to 6V from a receiver pack or BEC. Check the datasheet before you use a 2 cell lithium pack.
Sources
Last updated: November 10, 2026.