2007 G35S Sedan VQ35HR 3500 lbs (use 91 gas = 95 in Taiwan) 50% highway 15 miles per trip : 18-19 mpg 100% highway : 25-26 mpg (feel like superman on highway because of much higher cruise rpm)
2010 M35X Sedan VQ35HR AWD 4000 lbs (use 91 gas = 95 in Taiwan) 100% local 3-5 miles per trip : 12-13 mpg (full charged battery), 11-12 mpg(75% charged battery) 100% highway 20-21 mpg (Still feel much faster than GSF on highway because of much higher cruise rpm)
2017 GSF 5.0 V8 4000 lbs (use 91 gas = 95 in Taiwan) 50% highway 15 miles per trip : 17-18 mpg 100% highway : 25-26 mpg (feel a little bit slow on highway. Need to downshift to lower gear sometimes)
2000 Maxima VQ30DE 3200 lbs 100% highway : 28 mpg in Taiwan(use 98 gas)
PS: I believe if I can get 93(=98 in Taiwan) gas in California, I should be able to get at least 0.5 - 1 mpg better... In addition AWD in M35X suffers at least 1 mpg than M35 RWD.
I think my cars' condition should be very good. My son said when driving my G and M on highway he had to let off the throttle all the time. Otherwise he would hit the cars in front of him. Comparing with 2006 TL(3.2 V6) in driving school he sometimes had to floor it on the highway. You may ask me "Why are all my cars so good?" Nothing special!?! Just use good oil and change oil every 3500 miles. Believe it or not. Every time after I change my oil on my G and M, the oil color on dipstick is totally transparent (when the engine is hot) for at least the first 1500 miles... (Even my new GSF cannot beat that color!!!) In addition if you check my previous post, the tailpipes on my G & M are also cleaner than my GSF's!!!
By the way I never drive G and M slowly including my wife (I'm always the fastest one on the road except some crazy drivers. My wife is also fast but not as fast as I do) but with one exception which is my son... (Surprisingly the personality of my son is totally opposite!?!)
In my opinion MPG can be very different especially on city roads. So highway MPG numbers would be more comparable and show how good or healthy your car condition really is. Nevertheless you may have traffic jams on highway. In addition, you may cruise at 100km/h instead of 120km/h. 100km/h uses less gas than 120 km/h. The above MPGs I provided in the previous posts all were cruise at around 120km/h and very light traffic...