Hi, bought our 2015 Promaster 3500 diesel as a Winnebago Travato 59k June 2016. Very happy except for servicing. No service in Victoria BC. Have to drive an hour, not even near acceptable. At 28000 Km we are averaging 10.2 l/100k. Just added DEF for the 4th time. First thing I did after getting the van was to put on a locking 'gas cap'. Thought it a bit odd that there was a vacuum created in the fuel tank. Could hear the air go in when I opened the tank for fillup. All was well until last fall heading south on the I5 in south Oregon. Van stopped. All sorts of warning messages flashed on and were gone. Waited 2 hrs for a tow to dealer. Long story short. I had been sold a gas cap for a diesel and the bottom of the tank had been sucked up by the vacuum created by the sealing cap. Fuel gage registered 1/4 tank since it was displaced. Took the sealing washer out of the cap and we are back on the road. Tank returned to proper shape. Jokes on me!