Sorry guys, it's a fact (and sorry for the thread hijack!). Repeatedly measured full tanks going up and down CA and Denmark/Sweden. Speed usually 65-80 mph on TomTom GPS also supplying driven distance.
JW Performance C4 (1:1 3rd), 3.70 9" rearend with TrueTrac, 295/30R18 Kumho tires
351W built...