[fx_chip]

I'm sure it is. Probably all down hills.

Yes it's downhill and he probably paid the difference while going up. Someone asked him to make the clarification when he posted this MPG earlier and he confirmed it's downhill. Considering the fact that @ballisticexchris can be quite detailed I don't understand why he keeps omitting that fact.

 

[fx_chip]

No hills in south Louisiana but I must have had a nice wind to my back. All on a flat interstate. I drive like a grandpa ( because I am ) and I'm pleased with the gas mileage most of the time. Even city is never below 22.

Is your Passport 2WD or AWD?

 

[fx_chip]

With 2WD, open freeway and a lightfoot on the gas, 40.3 mpg is easily achievable.

 

[fx_chip]

AWD as well. Light input to throttle up or down is almost all front wheel drive with hardly any power going to rear wheels.

Judging from the profile pic, the OP's Passport is either an EX-L or a Touring, the 2WD version of both weights between 232 lbs (EX-L) and 272 lbs (Touring) less than the AWD version because of the absence of a rear diff, that certainly helps with mileage.