How to Read an RC Spec Sheet

Every product page lists a wall of numbers. Most beginners glaze over and skip to the price. Here's what each of those numbers actually means and which ones are worth caring about.

Motor specs

KV rating

RPM per volt with no load. A 2000Kv motor spins 2000 RPM per volt applied. Paired with a 3S (11.1V) battery: 11.1 × 2000 = 22,200 RPM unloaded.

What it tells you: higher KV = faster top speed, lower torque. Lower KV = slower but more torque.

Typical ranges:

• Crawler: 1000-1400Kv (torque priority)
• Basher: 1800-2500Kv (balanced)
• Racer/speed run: 3500Kv+ (top speed priority)

Can size

The physical dimensions of the motor, usually expressed as diameter × length in mm. "3660" = 36mm diameter, 60mm length.

What it tells you: bigger = more power-handling capability, more heat dissipation, higher continuous amperage. Big motors need correspondingly big ESCs and gearing.

Turns (brushed only)

How many times the wire is wound around the armature. Lower turns = less resistance = faster, hotter motor. Higher turns = more torque, cooler running.

• 35T: crawler-appropriate
• 17.5T: race spec
• 13.5T: fast
• 10.5T: very fast, needs capable ESC

ESC specs

Max continuous amps

How much current the ESC can handle without thermal shutdown. This has to exceed what your motor pulls under load.

Typical ranges:

• 60A — 1/10 brushed
• 100A — 1/10 brushless
• 150A — 1/8 brushless
• 200A+ — 1/5 brushless

Running a 150A motor on a 100A ESC = burned-up ESC in minutes.

Max cell count

Maximum LiPo S-count. "3-6S capable" means works with 3S, 4S, 5S, 6S LiPos but NOT 7S or 8S.

Exceeding this kills the ESC instantly. Double-check before plugging in a new battery.

BEC output

The ESC's internal voltage regulator for the receiver and servo. Typically 6V or 7.4V at some amp rating (usually 3-8A).

Matters when: you use a high-torque servo. A big crawler servo pulls 3A+ peaks; if your BEC only delivers 2A, the receiver browns out mid-steering-input (glitchy, jittery behavior).

Battery specs

Capacity (mAh)

How much charge it holds. Higher = longer runtime, bigger pack, more weight.

Typical ranges:

• 1/18 truck: 1500-2500mAh
• 1/10 truck: 3500-6500mAh
• 1/8 truck: 5000-8000mAh
• 1/5 truck: 8000mAh+

Cell count / voltage

See our LiPo basics guide. Higher S count = more voltage = more speed/power.

C rating

How fast the battery can deliver its capacity. Max amps = C × capacity in Ah.

50C × 5Ah = 250A max sustained. That's typical for most packs.

Real talk on C ratings: manufacturers inflate these numbers. A "100C" pack from a budget brand often tests at 40-60C in reality. Brand-name packs (SMC, MaxAmps, Gens Ace) are closer to labeled values.

Rule of thumb: 50C real-world is plenty for 95% of driving.

Servo specs

Torque

Usually expressed as oz-in or kg-cm at a specific voltage. 250 oz-in at 6V means it can resist 250 ounces of force at 1 inch from the output shaft at 6V applied.

Typical needs:

• 1/10 stock: 100-150 oz-in
• 1/10 with aftermarket tires: 200-300 oz-in
• 1/8 crawler with heavy tires: 300-500 oz-in
• Big drift car: 300+ oz-in

Not enough torque: servo can't overcome tire grip, steering feels mushy or refuses to return to center.

Speed

Expressed as seconds per 60° rotation. 0.10s/60° is fast; 0.15s/60° is average; 0.20s+/60° is slow.

Faster isn't always better — slow, high-torque crawler servos work great for crawling because smooth is more important than quick.

Material

• Plastic gears: cheap, fine for crawlers and light use; strip under heavy load
• Metal gears: most of the market; strong, reliable
• Titanium gears: premium, most durable

Chassis / drivetrain specs

Wheelbase

Distance between front and rear axles. Longer = more stable at speed, harder to turn tight. Shorter = more agile, twitchier.

• 1/10 short course: 310-330mm
• 1/10 crawler: 290-330mm depending on scale vehicle
• 1/10 drift: 255-260mm

Ground clearance

Gap between the chassis and ground at ride height. More important than people think for bashers (big jumps deform shocks — low clearance = chassis strike).

Gear ratio (drivetrain)

Overall reduction from motor to wheel. 11.8:1 means the motor spins 11.8 times for every wheel rotation.

Lower ratio (like 8:1): faster top speed, less torque. Good for flat-out running. Higher ratio (like 15:1): more torque, slower top speed. Good for crawling.

Gear pitch

How fine the teeth are on the spur and pinion. 32 pitch is fine (more teeth); 48 pitch is finer (more delicate); MOD 1 is coarser (very strong).

Matters when: replacing gears. Mixing pitches instantly strips both parts.

What the spec sheet doesn't tell you

Critical things that don't show up in the specs:

• Parts availability — a "better" spec sheet means nothing if the truck is orphaned
• Community support — how active is the forum / subreddit / Discord for this model?
• Stock setup quality — some trucks have great components but bad initial tune (shock oil weight, diff fluid, gear mesh)
• Build quality / QC — same parts from same factory can be assembled well or badly
• How it actually drives — specs don't capture feel

These factors usually matter more than ±10% on any single spec number.

The 2-minute spec-sheet summary

When comparing two trucks, here are the only 6 specs that really matter:

1. Scale — what size are you buying?
2. Category — what does it do best?
3. Motor + ESC power system — brushed or brushless, max cell count
4. Drivetrain type — 4WD shaft, solid axle, portal axle, RWD
5. Top speed claim — rough performance indicator
6. Weight — affects how it drives, transports, stores

Everything else (exact KV, specific gear ratio, servo brand, etc.) is tuning detail. Most of those you'd swap out anyway if you upgrade.

Focus on category fit and platform reputation. Specs are mostly tiebreakers.