So far the claims of this device are dubious at best. This scientist is funded by a company that makes fuel magnets. His work has only recently been published but no other independent experimental verification of his claims exists. There is some independently verifiable evidence that magnetic fields can lower the viscosity of crude oil however crude oil has a large number of chemical components and metals that are refined out when it is converted to fuel.
The following report has found no statistically significant improvements in mileage of this scientist's benefactor's device. This latest announcement from this scientist may just be an attempt to keep research money coming in by changing the magnetic field claims by this company to electric field claims.
http://wwwcgi.rand.org/pubs/technica...RAND_TR313.pdf
Until there is duplicated experiments and results by an independent party I will regard this research dubious. The key factor is if diesel fuel is indeed an electrorheological fluid. So far the only name that pops up in this area of research is this scientist. This is starting to smell a lot like the acetone scam in as far as the only evidence to back up the claims come from the person making them.