I had mine out this weekend......25F both started right up and ran great. Broke them both doing long jumps at those temps. Broke the engine mount, gas tank mount on the savage landed right on the engine from 25 feet up. Had about 80 feet of length to the jump and over rotated to death landing. Hyper 7 truggy conversion got the same treatment and suffered a broken diff housing and rear shock tower. Hyper 7 snuffed out the engine on landing, while the savage was still running and had to be shut down.