Arthur's probably right, they probably should find someone from the twenty-first century--something that sounds absolutely absurd if he thinks about it for more than a moment--to verify things for them before they go poking around in potentially dangerous machinery. James is relatively confident with the technology of his time, enough so that it's very tempting to experiment with the mess of machinery under the hood, but he's not an engineer and he does have enough sense to weigh the risks.

"I suppose it would be best to wait until the Aurora has passed." Begrudgingly. But since it's just curiosity driving him to want to experiment with the truck's engine, and it's not about attempting to use the Aurora's power to actually start the engine or anything, he can wait until it's safer to do so.

So instead, he glances over at Arthur, and asks something else he's curious about. "Are you from England?" The accent says yes, but Arthur's from nearly a hundred years later than James is, so who knows what accents might be like in that time.