[softgrow]

Fire and rescue appliances are a bit of a problematic thing to buy as they never go very far and are retired with low mileages.

In my Australian State, South Australia, this a huge contrast with police who buy new from the manufacturer, get a three or maybe five year service contract from the manufacturer and then sell them when the warranty expires and they've done around 100,000 km (60,000 miles). So no servicing worries and they get some tax benefits so it works for them.

Ambulances have less mileage and my guess is retire after 10 years. Ambulances are very standardised so can swap metro and country vehicles to get value from the asset. There was a "twin life" ambulance (http://www.old-ambulance.com/Twin-Life.htm) that had a long life rear bit on a light truck chassis so swap out the motor bit two or three times every 200,000kms, but these days vans are used. There was much sadness in the ambulance fleet buying community when Ford discontinued the F150 type chassis in Australia.

But your average (fire/rescue) appliance in the city or country has low mileage. In the city plenty of use but never have to drive far. In the country not much use but do drive further but end up the same a very old vehicle without much mileage on the clock. Trailers can be even older 50 or 60 years before retirement. Another issue with a fire appliance is they carry water which is heavy, three tonnes is a pretty common load. And have other readers have mentioned a monopoly on manufacture wouldn't help.

[waste_monk]

I have heard that the problem with ex-emergency services vehicles is they tend to have low distance on the odometer but drastically higher engine hours, particularly idle hours. That is, they may sit with the engine idling for hours at a time to maintain power to the lights, radios, and other vehicle systems, and are generally closer in wear and tear to a vehicle with several times the mileage.

Another problem I have heard of is that while the actual mileage may be low, the miles that are driven tend to be much "harder", in the sense that an emergency services vehicle may be accelerating and stopping rapidly, and generally being thrashed without regard for the vehicle, leading to increased wear on the engine and transmission.

It reminds me of the saying attributed to Jeremy Clarkson, about the fastest car in the world being a rental.

[trailrunner46]

Yes, trucks typically are running with the generator constantly on scene. Also many pumps are run on a PTO system where the transmission is put into a pump gear, further wearing on it since pumps can be run a lot on scene.