07 5.4L EB swb ~14-15mpg average. Hasn't seen higher than 17 or 18 mpg in about 100k miles. Lieometer is actually spot on accurate.
17 3.5L Plat EL Lieometer says 18.3 average, with a high of 21 if real careful. Hand calculating has shown a consistent ~1.2 mpg less discrepancy so I don't bother hand calculating anymore. So real mpg is about 17.1-17.5 mpg avg when I'm driving 80 mph on the highway. Even 5 mph less helps a lot. I get ~19 when I'm cooling it at 70-75 without traffic.
17 3.5L Plat EL Lieometer says 18.3 average, with a high of 21 if real careful. Hand calculating has shown a consistent ~1.2 mpg less discrepancy so I don't bother hand calculating anymore. So real mpg is about 17.1-17.5 mpg avg when I'm driving 80 mph on the highway. Even 5 mph less helps a lot. I get ~19 when I'm cooling it at 70-75 without traffic.