I have towed a bit with the BJ70 and here is what I have found. I towed an empty 16foot car hauler from San Diego to LA. I was using my AXT turbo 70 series, I added a receiver to the custom steel bumper. Hauling it was borderline, and the trailer wieght is 1200lbs. Now if you are hauling anything over 2000lbs you need electric brakes, the 70 should not be hauling anything more than 1200 at best, and it is too short to legally (in USA) haul a 16 foot or longer trailer. DO NOT DO IT!!! The 70 series even turbo'd can't handle that much wieght. and if you come across a big hill, you will get passed by even the slowest big rig.
I can tell you if you want to use a TLC to haul a 4000 lb vehicle you should use a 100 series or a supercharged 80 series, I use my 80 series to haul my 70 series on a my 16' trailer (so the net wieght with trailer is a little over 5000lbs) and it does pretty good. I do have my 80 series supercharged and it puts out just a tad under 300hp. I have also hauled my 70 sereis (net wieght is about 3800lb's) with my 100 series using my same 16' trailer and it also does pretty good the mileage drops off a little more on the 100 series and it is not quite as powerfull as the SC 80 sereis but it does pretty good. Keep in mind that the wieght of the 100 series is 1000lbs lighter than my 80 series and the 100 series has 225hp verses the 80 with 300hp all things considered the power to weight ratio is close between the two.
I hope this helps.
G'Day,
Michael
