Just got back from my Houston trip. I was running SW1, TQ-1, TM-default, RP-1, VGT-1. Topped off before I left and, for the first time in a long while (several thousand miles), reset the overhead MPG meter. On the way up, negligble wind (~5mph), cruise set at 63-64mph, bobtail and unloaded (just me and my gear). When I got into Houston, the overhead was reading 24.4mpg, the highest I think I've ever seen it. After driving around Houston for a bit taking care of things, I pulled into my hotel parking lot for the evening and the overhead read 24.1mpg. I had 270 miles on the tank of fuel and the fuel gauge was at 3/4 tank exactly.

On the way home today, there was a significant head/crosswind, 30-35mph. Crazy wind, but normal for this area (coastal). At half a tank on the fuel gauge, i had 410 miles. By the time I got home, overhead was down to 22.7mpg. Filled up, 510.6 miles total, hand calculated 20.5mpg, fuel gauge was reading just below 3/8 tank. If the overhead can be trusted as an indication of trends (which im still not sure is the case all the time), i probably got around 21.5mpg actual on the way up there and 19.5mpg actual on the way back. Considering the traffic and winds today, im pretty impressed.

So, this setting is staying for a while. After about 2000 miles in the past couple of weeks on this setting, i've gotten used to the near-stock power levels. The truck drives easy, still has more than plenty of power, and I REALLY like knowing I can hook up to the trailer and drag something heavy across Texas without having to adjust anything. Just hook and go. I don't have to worry about the clutch slipping (for the time being, that is), or anything else. Im happy.

This also just reaffirmed my belief that, with my truck set up the way it is (leveled with true 35" tires), wind resistance is the real mileage killer, far moreso than grades. My single best tank of fuel is still right at 21mpg where I was driving up to central Texas and back through the hill country. Away from the coast so little to no wind, but constant ups and downs. The truck ate the grades up, but tends to get thirsty with a heavy wind. Guess the only way around that is to move away from the coast, something I will surely do if the right opportunity presents itself.

Cliffnotes: I like SW1, TQ-1, TM-default, RP-1, VGT-1. If you are truly ONLY looking for fuel economy with Smarty and are more than happy with the stock power levels of the truck, this might be the settings for you. It is much gentler on the drivetrain and seems to work very well with the truck.

Warning: The power of Smarty at higher levels is addicting. If you've been running higher tunes for a while, it's going to be a culture shock running SW1 for the first while. The truck will seem sluggish, non-responsive, and disappointing. If you aren't totally hooked on the power, however, i think there is better fuel economy to be had on the lower tuning levels. As with all my other posts in this thread, these are purely my own impressions and opinions based on my own hypotheses and experiments. These do not, in any way, reflect Smarty FACT nor do they guarantee you will see the same results on your rig. Take it all for what it's worth, which isn't much I admit.