I saw somewhere online, the previa having a 3800 Lbs curb weight.  I'll put mine on a scale b4 the trip south. 

  The previa door badge says 5215 LBS (I don't have the manual, never needed it), I'm a little over 200 lbs, and I had about 3-400 Lbs of photogear and luggage with me....  average in about 70 Lbs of fuel, and about 70 lbs of dirt, and we're pretty damn close to 3 ton. 

xB is supposed to be 2600-2700.... or around half the weight. 

The Previa has a 2.4 liter motor (same block tipped on its side??), and an auto slush-box 4 speed tranny, with rear wheel drive.    Previas don't look huge, but they are quite substantial vehicles.  and deceptively roomy on the inside. 
I really don't baby it either... I was obviously going 75ish+ most of the time I was on the road to make 63 average MPH.  Looking at a 12 hour trip, I was more interested in getting there than saving a few MPGs.

I do run my tires at about 10 PSI higher than suggested to help reduce rolling resistance.  Anyone try this on your scion? 

I'll definitely post again after my trip south (I'll have a full load, including a motorcycle stuffed inside)

Yah, so I don't own one yet, but both my bro and I are both considering.

Here's what I don't get.  I just drove up from Raleigh, NC to Boston, MA area.  In my 91 toy previa.  on the trip up, which included stop and go hiway, and at least 50-80 miles of rural routes/ with some stop lights, I got just an RCH under 26MPG.  This from a vehicle is bigger in every dimension, can carry 7 people in complete comfort, and that prolly weighs twice that the xB does, and has 210K miles on the odee, to boot.  It has AC (x2), PS, PW, PL. 

I kid and say I drive like a grampa, but i really don't... I do what every one else is doing, except i don't follow to closely.  and I keep my foot off the brake.  I averaged 63 MPH for the trip, including pit stops, and RI, CT, NY, NJ, MD, etc traffic and toll tie-ups and massive construction delays (WTF with the roads in the North East guys??? That's just embarrassing!). 

The van gets it's oil changed every 10K whether it needs it or not (it looks like honey when I finally change it)
and the plugs are original at least from 60k miles (which is when I bought it)

been up her for a week, mixed driving, stuck in construction (WTF???) and averaged just under 24.5MPG.

Anyone care to tell me how this is possible? 
I'd love to get a new car, but I can't justify it if this is the best they can do.  I can justify spending some money fixing my old egg.... especially if it gets what a new shoe-box on wheels gets. 
Come to think of it.... my 2000 trans am, with a 350HP 5.7 liter, 3800 lbs at the curb, an auto tranny and convertible fun, gets mid 20s on the highway too...  How come new cars get such incredibly crappy mileage???  I look at the xB and figger it should get mid thirties in a race.  what is goin on?