Ford guy here. When I think of emergency and reliable vehicles, I think of Ford and International.
Cop cars - Ford Crown Vics and Mustangs (although the new Dodges are sweet)
Ambulance - Ford F350 Diesel
Fire Trucks - International aka Ford
School Bus for kids - International aka Ford
Swift Trucking (largest trucking company in USA) - International and Volvo
Bottom line is all the big 3 make good reliable trucks. All 3 of them have their quirks. Same drill goes for all the toys we have such as motorcycles, boats, snowmobiles, ATV, etc.
Hell even Kia and Hyundai make good vehicles nowadays. Both of those brands were cheap entry level players when they started out in USA. But if you go back 30 years, same thing happened with Toyota and Honda. Cheap entry level cars that rusted out before your 5 year car payment was done.