Here's something I dug up on the inter-web thingy about a 1974 tire comparison test between standard 9x16 NDT and Brazillian run flat tire.
It is a PDF file.
http://www.dtic.mil/cgi-bin/GetTRDoc...c=GetTRDoc.pdf
Scroll past some of the charts and there is some neat info on a test:
5000 miles long, 41.7 mph average throughout, with:
3500 paved miles, 45.4 mph average,
750 secondary miles, 30.2 mph average,
750 cross country miles, 22.6 mph average.
724.4 gallons fuel used
6.91 mpg.
And I get wore out driving to the store......
Scott