US Mail delivery trucks - CNG run or NOT???

[bbriscoe]

This week I pulled up at QT and waited behind a mail truck to pump gas.  The truck had a CNG "This vehicle runs on clean natural gas" sign on it.  He was filling the tank with unleaded.  What gives?

[Wrinkle]

Simple....mail carriers don't have to complete their routes if their trucks don't run.

Actually, I think a CNG conversion really makes the vehicle "Flex-Fuel", so it can run anything.

The carrier probably found themselves enough short that they couldn't make it back to the fuel stock provided by the government.

Wild guess.

[sgrizzle]

CNG vehicles run on CNG only. You're not going to get unleaded into a pressurized tank no matter how hard you try.

Could be the vehicle was mis-labeled or had body work done with parts taken from another truck.