Rovan 1/5 Scale 360F5 36cc Gas 4WD On-Road RTR Race Car

All four wheels are driven. That gives more grip under power, especially on loose ground.

• The cost is more parts to maintain.

A two-stroke engine running gasoline mixed with oil, used on the largest cars.

• It has no motor KV or battery rating.

Ready to run: built at the factory with the electronics installed.

• Some come without a battery or charger; the maker's box contents say which.

The maker's nominal size compared with a full-size vehicle. It works more as a class label than a measurement.

• A 1/10 monster truck is far bigger than a 1/10 touring car, so compare length and weight for real size.

The maker's product number for this exact version.

• A V2, a new color, or a kit instead of an RTR usually has a different number, and parts can differ between them.
• Check it against your box or receipt before ordering parts.

On a nitro car the gear on the engine is the clutch bell.

• Its teeth work like a pinion's: more teeth gear the car taller, for more top speed and slower acceleration.

The large gear the pinion drives. A bigger spur with the same pinion gears the car shorter.

• Pinion and spur must have the same pitch, or tooth size, to mesh.
• On a nitro car the clutch bell drives it.

Every reduction after the spur, multiplied together: transmission, differentials and axle gears.

• It is fixed by the design; the gearing you change is the pinion and spur.

How many times the motor turns for one turn of the wheels. A higher number is shorter gearing: more acceleration and pulling power, less top speed.

The outside diameter of the mounted tire, tread to tread. A taller tire covers more ground each turn, which gears the car taller.

• At high speed tires can balloon and grow, so the real gearing gets taller as the car goes faster.

An engine has no KV rating.

• Nitro engines are sized by displacement in cubic inches, such as .21.

An engine car has no drive battery.

• A small receiver pack or a BEC powers the radio and servos.

An engine has no KV, so a theoretical top speed cannot be worked out from the gearing alone.