How we research

Products

Every product on this site comes from a current Amazon listing, retrieved through Amazon's product API, with its real title, image and price. We read specs such as scale, motor type, LiPo cell count and any stated top speed from the listing itself. If a listing does not state something, we say "not stated" rather than filling the gap from memory.

We choose picks from published specifications, parts availability, manufacturer documentation and patterns in verified owner reviews. We have not driven every car and we never claim to have tested products in person.

Calculations

• Motor RPM = KV x volts, using 3.7 V per LiPo cell nominal and 4.2 V full.
• Final drive ratio = (spur / pinion) x internal ratio.
• Top speed (mph) = motor RPM / FDR x tire diameter (in) x pi x 60 / 63,360. We show realistic speed at about 85 percent of theoretical.
• Runtime (min) = mAh / 1000 x 0.8 usable / average amps x 60.
• Max continuous current = Ah x C rating. Charge time = Ah replaced / charge amps, plus 10 to 15 percent for balancing.

Where a page uses an assumed value, such as an internal ratio or a typical average current draw, it says so next to the number.

Prices

Prices are the listed price when we last updated the catalog and change often. The price at checkout is the one that counts.