Mugen Seiki MBX8T ECO

The kind of vehicle the maker sells it as. It sets what the car is built to do and which cars it is fair to compare it with.

• A truggy is a 1/8 buggy with wider arms and truck tires: more stable and more forgiving on rough ground.

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

• The cost is more parts to maintain.

Sold without a motor, so you choose the motor, ESC and battery yourself.

• Rows that depend on the motor say so.

A kit you build yourself from parts.

• Most kits come without motor, ESC, servo, radio and battery, and many without tires or a painted body.
• The manual lists what to add.

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.

The small gear on the motor shaft. Fewer teeth gear the car shorter: quicker acceleration, lower top speed and a cooler motor. More teeth do the opposite.

• On this car one tooth changes the gearing by about 6.7%.
• Racers change the pinion to suit the track and the class's motor rules, and often compare setups by rollout rather than tooth count.

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.

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.
• This one is worked out from the tooth counts the maker publishes.

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.

• Among 1/8 truggies in the catalog, the middle half run between 13.9:1 and 15.2:1 on stock gearing; this one is 14.1:1.

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

• Race tires wear down over a day, and a smaller tire gears the car shorter.

Motor KV is the RPM a motor turns per volt with no load.

• This vehicle comes without a motor, so there is no stock KV; it depends on the one you fit.

The highest LiPo cell count the maker rates the electronics for.

• This vehicle comes without electronics, so it depends on the ESC and motor you fit.

It needs a motor KV, and this vehicle comes without a motor. Fit one and the calculator works it out from the motor's KV and the gearing.