How many miles should you put on a New truck before you start towing?

 

Not that I would recommend this but I only had about 150 miles on mine before I towed 14,000 pounds of fifth-wheel and boat up mountains and through the desert in 105 degree heat. I just took it real easy and monitored the gauges constantly. I now have over 50K on it and have never had any problems and it requires no additional oil between 5,000 mile oil changes. Maybe I'm just lucky.

Given the opportunity, I would give it about a thousand miles before towing. In reality though, with today's moly rings, there is almost no time requirement to allow the rings to seat.

Here's a quote from the owner's manual: There are no particular guidelines for breaking-in your vehicle. During the first 1,000 miles vary speeds frequently. This is recommended to give the moving parts a chance to break in.

 

The owners manual for my '04 said 500 miles (page 5 under BREAKING-IN YOUR VEHICLE)

 

I towed my 8000# camper the day after I got it. I also took it easy. No wide open throttle hills. I have about 33,000 now and no problems or oil consumption.
If your going to synthetic oil I would wait untill the recomended 2000 miles for first oil change. It seems like a long time, you will be tempted to pull the plug before that, but the engine won't break in with synthetic.

 

I towed next day after getting my truck Odo had 40 miles on it I just was gentle. 38600 miles now and no trouble.