[Vwdiesel] VW diesel exaust sound

[William J Toensing]

I have had no experience running a VW diesel with a straight pipe. However, I did own an Argosy 26 foot motor home that I wished I had never sold. A prior owner had replaced the stock Chevy 454 gas engine with an Isuzu 6 cylinder industrial turbo-diesel. It had a streightpipe with no muffler. I was told the turbo quieted the engine enough to make it legal. It was coupled to a GM Turbo 400 automatic & a Gearvendor under/over drive. I got anywhere's from 12 MPG to 17 MPG & usually 15 MPG. I currently own a Rockwood diesel pusher with a Spartan chasses & 190 Cummings turbodiesel.It only gets from 9 &  one half to 10 MPG. I think it needs a new thermostat as it only runs around 140 degrees F under normal conditions & suspect this contributes to poor MPG. I wonder if removing the muffler would help fuel economy? However, this is a heavy rig weighing about 20,000 pounds.