Diesel vs. Gasoline

I drive a 2002 VW Jetta GLS TDI.  It's an automatic.  I bought it back in 2005 when gas prices were a lot different than they are now.  I ran a comparison of prices with my older car, a 1995 VW Jetta GL.  So here's what it looks like today after I paid $4.22 for biodiesel (B5).  Granted, these are highway figures.  My old Jetta got around 25mpg in city and the diesel Jetta gets about 32-33mpg in city; 35mpg if I'm really babying it.  These prices are current as of today.

I think this guy should take a look at my comparison.  He's paying way more than he should.

Gas: $3.42 - 31mpg on highway
BioDiesel: $4.22 - 39mpg on highway
DinoDiesel - $4.09 - 41mpg on highway

400 miles of travel

Gas - 12.9gal used - $44.12
BioDiesel - 10.26gal used - $43.30
DinoDiesel - 9.76gal used - $39.92

$ savings in %:
BD and DD are 1.8% and 9.5% cheaper tank for tank than gas, respectively.

fuel savings in %:
With BD and DD, you use 20.5% and 24.3% less fuel than gasoline, respectively.