possibly an Oshkosh W800
Mayday is the fire truck in Propwash Junction and appears in both movies.
In Planes, Mayday is first seen taking fuel from Chug. He then leaves just before the delivery truck carrying Roper arrives in Propwash Junction. Later, Mayday cheers after Chug tells him and some other citizens that Dusty Crophopper is in the Wings Around the Globe.
At the end, he is seen in the crowd celebrating Dusty's victory.
Planes: Fire & Rescue
Feisty old Mayday has been Propwash Junction’s fire and rescue truck forever. He’s always rarin’ to go, but he’s lost a little speed over the years. Plus, his hoses are leaky and he can’t see much without his glasses. Propwash Junction is growing fast thanks to resident-turn-big-time-racer Dusty, so Mayday might be in over his headlights.
"Listen to my new siren!"
"Good luck Dusty!"