The CVT should keep the engine revving quite low at highway speeds, right? Any manual control over the transmission? It would be interesting to manually keep the transmission at those low rpms and increasing the load without increasing rpms. Then you should reach a better BSFC "island".
That 3.5L V-6 must be a sweetheart to drive. I was eying a V-6 with MT, and Nissan is the only manufacturer of affordable family sedans to offer that combo. Well, when the Hyundai with the 2.0L turbo I-4 arrives I may have more options.
Do you do a lot of highway or city driving? In any case try manually "down-shifting" to use the engine to brake for you. Less brake wear and as an added bonus DFCO (deceleration fuel cut-off). Timing stop lights also helps a lot. I'm curious about your driving style/hypermiling experience at the moment, and how that all fits in with a CVT.
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