Of course, this means diesel is displacing residual fuel oil. So refineries have to figure out how to get rid of residual fuel oil, which means *all* refineries have to upgrade to recrack/upgrade/process the residual fuel oil (they can't just store it in tanks forever). This means the spread between refinery costs and end-user costs has to increase.
And this increase in diesel demand no good for crude oil producers, because this demand will go straight into refinery capex and opex costs to get rid of the unwanted residual fuel oil. Refineries will probably pad out their margins a bit for safety, too.
I've been predicting for a while that we'll start to get a divergence where the "crack spread" increases; prices at the pump go up while prices at the wellhead go down. For those of us who want to see the end of the petroleum age, this is of course ideal. I can see several different phenomena which would lead to this widening. Is there any good way to track whether it's happening?