The price of racing.
I always build my engines to run on pump 93 for a few reasons, with my work schedule I can't race every weekend, I like to drive my car (a lot) on the street and most stations in my area have 93, and finally, cost. I'm sure I'm giving up some ET and MPH by knocking off a couple points of compression. But it's pretty cool to run 10.0 at almost 135 mph one day and drive to the car to work a couple days later with the only changes being adding the exhaust and air cleaner.
I was out tonight and saw diesel anywhere from $4.30 to $4.50 per gallon and I don't think this is the highest I'll see it. My guess is there will be some diesel tow rigs parked this summer.