I'd say low gear for low speed.
I drove a 10 truck once, that had a severe mis-match of trans and differential. It's top speed was just under 35. It sure did piss people off behind me. I could be first in line at a stop light, and by the time i'm through 5 of the 8 gears, I might be half way through the intersection. And for those who don't know this, in a truck, once you get moving, you usually don't clutch. I could get away without the clutch from a dead stop. I could just jam it into first, and it would(almost) lurch