Quote Originally Posted by wbute View Post
Is it better if you have the fan on to pressurise the cab?
It is. I often drive with the top tailgate up (just like the old days.....) and if I stick the fan on there is no noticeable fumes.

It probably still has a lot to do with exhaust exit location and tailgate seals for a lot of vans because there seems to be a great discrepancy between what some people say (in other related threads) about fumes. Some say they have no problem, while others are getting gassed.

I'm glad it's no problem on my van because I love cruising with the tailgate up.