Why is Peterbilt backwards?

First off it would be very difficult to put fuel in a def tank as the nozzle is different and won't fit, and any driver who puts DEF fluid in his fuel tank perhaps should opt for an attendant to come outside and fuel his truck. The truck your friend has is a 389 not a 379 they never had def fluid. Those hoses do stretch quite a bit and it should not be a problem. The new 579 day cab can be ordered with a large capacity def tank. Going to have to get use to seeing these trucks around without the condo. Kind of reminds me of a kenworth , even has the same headlights. I guess I still like the rugged old aluminum cabs. The 579 has the same layout as a t600 , very similar.

 

Dash layout that is.

 

I have a 2012 386 and mine is on drivers side

 

That should help explain that!! Nice Job!

 

(1) & (2) Yes, Most engine makers are using DEF to meet emission guidlines.

 

Why is the fill cap on the def tank so low. It seems like top 1/4 of the tank never gets used? I know every engine model is different , but how much def are you using a day? 3-5% of the days fuel maybe that's what I've seen in ads. Tks

 

I can get about a week on full tank(20 gallons)