MPGs from our last tanks;

Insight 102.2
VW Golf TDI 48.7
Suburban 10.2

MPG for last year;
Insight 13527 miles at 90.7 MPG =149 gallons
VW Golf TDI 25056 miles at 47.9 MPG =524 gallons
Suburban 3009 miles 11.1 MPG =270 gallons

It's not a fair comparison because I have never pulled a trailer with the Insight but the Burban used 121 gallons more then the Insight to go 10518 miles less....Louis