I see that the rack was already mentioned, along with short trips, but there's another variable I don't see above - the 3-zone AC.

Here's my summary: short trips (5-7 minutes one way), rack, ladder, stock "all terrain" tires on 20" rims (yet), no heavy gear (yet) - all in all, I'm lucky if I'm getting 15mpg in the city. Right now it's sitting at 11-12. The best I ever got on long trips was probably 18 - but may have been all downhill. That is given the fact that I drive it very gently (at least compared to how I drive my other car, a German V8 ). Costco gas (it never gave me problems with other cars, see no reason to use anything different now).

Anyone here that can compare a 2-zone and 3-zone AC fuel consumption? On a tangent, 3-zone was a must for our crew (there are people who physically can't stand heat) but <censored>, I wish there was a way to just completely shut it off when there are no passengers in the back - it's simply a waste of energy.

Last but not least - I have a hunch that most of the gas is spent on recharging that battery; I never used the trickle charger during the first year of ownership but now I'm toying with the idea of using it just to see if it makes a difference in fuel consumption.

 

Thank you again for all the feedback and advice — it was both helpful and timely. I had the opportunity to put some of it into practice on a recent drive to Pittsburgh and made a few adjustments along the way.

After increasing tire pressure by an additional 5 PSI in the fronts and 4 PSI in the rears (I am running Pirelli Winter Scorpions, which, as an aside, do not seem to hold PSI consistently and I generally do not like), the Defender immediately felt more responsive and noticeably less sluggish on turn-in. The trip was primarily highway driving along the I-90 and I-79, where I maintained an average speed of approximately 73 MPH.

Fuel economy improved as well, which was encouraging. Warmer spring temperatures may have contributed slightly, but the most significant improvement came from switching the drive mode from Comfort to Economy and turning off the air conditioning — which, in Canada at this time of year, is not exactly essential. That adjustment had the single biggest impact on fuel consumption and brought the average up to 18.6 MPG.

Overall, a very worthwhile exercise and a reminder that small adjustments can make a meaningful difference in both performance feel and efficiency. Thanks to @BritCars and @Sir Lands-a-lot for the pointers!

 

I've noticed that every 10mph from 50 up makes a pretty big difference in MPG. This thing is a brick in the wind. given a long enough distance on cruise control I can see 20mpg at 75mph, but on shorter trips at the same speed it's more like 15mpg. factoring the almost $100k msrp the cost to fuel it becomes insignificant but highly visible because it's the one number that you see every week.

 

Update from my prior post when I got 18.4 mpg coming back from VT to south of Boston. This past trip I used ECO and got 19.3, saved a couple gallons. Pretty decent actually.

 

@theblue and @SpyHop both the exact experiences I had. Drag coefficient and ECO efficiency meet somewhere around 72mph
Thank you both!