High TierDrivin': Maneuvers - You no longer have to worry about falling off a mountain and exploding the truck. You can also do truck combat stuff well and position the truck very accurately, for example, entering combat, you could probably block off their routes with fancy maneuvers.
Steely Nerves (gives you a bunch of fucking bonuses to other skills. Lucky you.) Fatigue depends on the mood and how long he does it for. Being Steely Nerves for a day probably tires him out. Half a day at a stretch sounds reasonable and he needs breaks/rest/food/coffee before and after long sessions)
MediumFightin': Punchin'decent but can be powered up through steely nerves moods, alcohol, gasoline and such (each is +1 or about +half a tier)
Normally, he can handle 1-2 opponents at a time in lethal combat and smash a car and send it flying with his punches.
His specialty is punching shit. His style is boxing.... bar-room?
Crab on hot steel tin? - a hotass reaction skill to danger. He moves and reacts fucking fast.
LowLiftin'Weak Lift is okay but frankly, let's wait and see if people join the thread and then we can decide roles in more concrete. Either way, you can use Steel Nerves and alcohol to supplement any weak skills.
For your last skill, maybe it can be something George does to relax, let off steam, vent, let go, or alternately it could be something that winds him up and makes him more intense. What does George do for hobbies? I had the idea that he might sing to himself: a lot of truckers do this when they're alone in the cab. He might also have some relation to gasoline and the truck, hence he could use fuel in some way.