Last weekend I installed my tvs 1900 and it runs pretty good. Might of lost about only 1mpg driving around town, I can deal with that.
Well today we drug the camper about 600 miles. It pulls the 5500 lb camper so much better fi but I was shocked how much my mpg dropped. Went from about 11 mpg NA. Down to about 7 with the blower, towing at the same speeds. I expected it to drop alittle but not that much. Think my tune is too rich, gonna try to contact Justin to see if He can help.
Any other thoughts.

 

Gotta remember, when you up the power, you simply will not get better gas mileage. I can't even get higher than 16-17 mpg on the highway now, whereas not too long ago I was able to get well over 21. Up the power, up the parastitic loss, etc.

That being said, I wouldn't expect that much of a drop. If anything I thought it may go up 1mpg or so since the truck wont need to downshift up hills and stuff while towing. I agree that your tune is probably off.

 

When we did my friends truck he went up towing around 3mpg. It was a 4.8 with a 112. Go figger.

 

Does not shock me, my setup drank fuel when towing too with the blower. Towed great though haha. My stall killed my fuel mileage more then anything I think. If you are in boost then you will be running a richer AFR, which means you will be dumping more fuel. Gotta pay to play.

 

Ouch! 7MPG. That sig pic makes it all worth it tho. Not to jack, but got any vids like that smokin the hides? I hope ya get it sorted out.

 

x10 7mpg ouch!

Sounds like you need a dedicated tow tune you could load in when towing???, or have a spare PCM with one .

All in all though mpg suffers when we mod stuff most of the time, we just love using all that new power .

 

I didn't lose any mpg when towing. The extra torque keeps mine in overdrive, with the torque converter locked, much longer than when naturally aspirated. Even when in boost it's very low boost so it doesn't suck gas.

 

1 bar or 2 bar tune? If it is in boost all the time due to engine load, then you will be running at a richer AFR. It may be richer than it needs to be if you are just barely into boost. IIRC I used to get better fuel economy in 3rd gear when towing with my Radix because I was able to maintain enough engine vacuum to keep the bypass from closing. This was even though I was running at a higher RPM.

I believe that Magnuson used to sell "towing" kits that came with a larger pulley, so you wouldn't be into boost all of the time. If your truck does mostly towing, that makes sense. If you want to play, then you give up some major ponies with a larger pulley.

 

I tow my 5k trailer in 3rd gear and still have TC lockup. I only see boost on hills, on ramps and passing.
Without towing I used to get 18mpg hwy but after last mod, Radix, I dropped to 16mpg. I believe it is due to parasitic loss from the Radix.

 

What size pulley are you running? you shouldn't be seeing that poor of mpg imo.