Another 7,000 supercharged miles completed......all good. Fully loaded and going up very steep hills as well as some off-road. 110F in Phoenix to about 20F. Highest elevation about 8,000ft
The biggest test, however, was today - passed the California SMOG test which I was quite apprehensive about. Fortunately, no problems.
So far, the vast majority of the use has been towing. The modest amount of unloaded regular driving shows that the mileage is still the same 22-23mpg that you get with the V6 - but you have 400hp under your right foot when you want. I will say that this truck is horribly equipped for spirited driving that uses the full force of the supercharger. It gets pretty squirly, but surprises the heck out of other fast-ish cars. The exhaust is OEM, so very quiet. The transmission shifting gripes I spoke about earlier have largely been resolved by just calibrating the tire size. Just before the supercharger install, I swapped the 20" wheels with low profile tires for 17" with high-profile tires. the overall diameter was about 1" less than the OEM wheels so the speedometer was off. The wheel speed is how the computer maps shifts so when I got is calibrated properly, it shifts better.
One of my biggest concerns was reliability and drivability. It still starts just like a normal stock truck in a very wide range of temps with no trouble while running open loop. The general driving experience is benign, but with the supercharger whine being unmistakable when the hills come in. When it starts making power, everyone in the truck knows what is under the hood. It is not bad, just noticeable.
Gas mileage is about the same, but only if I drive the same speed as before the supercharger. The practical reality is that I am able to keep my speed up even on the hills, so the overall mileage goes down a little, not enough for me to care. My wife is really happy we get to use this particular truck as out adventure vehicle even though it was never designed for it. I would guess that the towing performance is similar to the V8 Hemi's although it is very difficult to compare. When this truck completes its adventure duty - my next tow vehicle will certainly be a diesel 2500 or 3500 even if we still have a small trailer. For those that followed this thread, you will know that I like truck to be miles from its max capacity. The official capacity numbers from the manufacturer are ridiculous - they do not account for hills, altitude, or temperature. They also don't account for driver experience.
A supercharged V6 does work for towing - but not exactly the low-cost option.