Don't know what year, model, ect of your Tacoma is but I've been able to average around 12 mpg plus pulling my 180. I assume if your Tacoma has an automatic transmission that your shifting it in manual between 3rd to 5th gear (sometimes on the super slab and long flat run I'll shift into 6th) and that you have the ECT on if have that feature? That seems to help increase my mileage with my Tacoma.

One reason why fuel burn numbers always seem to be all over the map even on dead flat roads with the same tow vehicles, same road speeds and even drivers is due to headwinds or tailwinds. Since at freeway speeds about 2/3 of your horsepower while towing is going to overcome air drag on that big box and only 1/3 goes to rolling resistance, even a few mph of wind added or subtracted from your road speed can make a huge difference. And air drag goes up 4x when you double your air (not ground) speed. Say you had an almost unnoticeable 5 mph headwind going one direction at 60 mph, then you turned around and went the other way, also at 60 mph. That would cause about a 4 mpg change in fuel economy even on a dead flat highway.  

I agree that wind resistance plays a big part. It's easier to go slower on country roads than the interstate, plus you see better scenery a lot of the times. I've never been in a big hurry. (I drove a VW bus for seven years in the 80s and 90s!)

Exactly! (Mine was a '67 EZ-Camper with 53 horses but it was still slow. The pre '68s had the reduction boxes on the rear wheels and could climb better but didn't have the top speed that the non-split window busses had. Like you really needed to go over 55 mph in a bus!)

I always laughed when I would look into my side mirror and watch the panicked drivers behind me as they serpentined back and forth trying desperately to get around me! They ALL had the same look on their faces!

I've always disliked impatient people.

I learned a lot from driving the VW bus. It's almost like a Zen thing! (Also it helped to think about the quote in the John Muir 'Idiots Guide to VW Repair' that said, 'If everyone drove like they were strapped to the front of their vehicle like an Aztec sacrifice and would be the first thing hit in an accident, then people would be a lot slower and safer!) 

Those reduction boxes really meant you were stirring that long gearshift a lot getting going, but they gave you great ground clearance. I eventually got a 56 bug with a bad 36hp and swapped the 40 horse from the bus into it, then got a 1600 dual port for the bus. Then I actually could go 55 mph in it and climb hills at more than 10 mph. Then later I had a 72 Westy, that was really a step up...

There are places you can rent old Westy campmobiles now if you want to recreate that zen feeling. Check out thesamba.com if you haven't to see what those things go for these day...

And we're way way off topic now...

Now with that sentence your giving me flashbacks and they are not good! Between all my VW's bugs and van, I wore out my copy of the Idiots Guide to VW Repair. One of my fondest days was the one I sold my rid of my 66 Micro-Bus, that seemed to spend more time broke down then running. Never in my wildest dreams did I ever think that today one in good condition is worth mucho-denaro!

Westies have a cult following now

We always had vans,but they were the old Ford econolines

Vann

There is a huge VW place here locally in Los Osos called 'Go Westy' that does repair and sales. The used ones on their lot are astronomically priced! For the money I'd rather have my new rPod!

Maybe your friend bought my old blue and white 66! ....  People pay crazy prices for Vanagon's and the old Micro Buss'es. Both of them had junk motors IMHO, the air-cooled motors they put in the Bugs and Vans where way to under-powered in Vans and not much better in the Bugs! The later water cooled Van motors were also a disaster in the making. Though what I do find very cool is that there are a few companies beefing up old Westy Van's suspensions, ripping out Volkswagen motors and putting in place Subaru motors. Now that is something if I was single I'd definitely be interested in but since I'm not the R-pod fit the boss and I perfect.