Driver for mileage

My 07 Charger R/T Daytona currently gets 27-30 at 65-70 on the hwy (making sure that the cylinder deactivation or MDS is working) and 15-18 in the city. Not bad for a 4,200 lb beast that runs mid 13's.

I had a slant six 76 Duster for a while with a 4 spd. 30 mpg were easy on the highway and it only turned 1,800 rpm in 4th/OD.

-Justin