My last two trucks...bought them...took straight down for a hitch...went home and hooked up and took off. This current truck had it's first 5000 miles on it hooked up other than the 175 that was on it from dealer miles and getting the hitch put in.

Not saying that it is right or wrong, but around my place, a truck with 5000 miles and none pulling a trailer just isn't practical. at 30,000 miles, it doesn't have 5,000 total not pulling a trailer.

My diesel had the same 500 mile restriction which I followed. I was told a replacement engine installed, would be $10,000. I've built many motors, raced some cars and been around engines treated well and some not so.

The two areas of concern in breaking in a motor are the bearings and rings. Rings are best seated at a high rpm. Their wear and seating will determine how much oil your motor will use. The bearings will determine how much life, the bottom end of the motor will have. They usually should be eased into usage, with varying rpms and loads.

Today's machining practices are far superior to those of several year's ago, and the break in periods are much shorter. A new motor will still have metal machining  particles that the new oil will flush out. So initial oil changes are a good idea. Don't use synthetic oils until the second or third oil change and your rings will have a better chance to seat. Some new cars have this oil installed from the factory. They also allow that an engine that consumes a quart of oil per 1k of travel is "normal consumption". None of my vehicles use any oil between scheduled oil changes.

I have a lot of money in my vehicles and don't want to spend any more than necessary to keep them running a long time. Proper maintenance and break in periods will ensure the longest life span.

Gard

We *always* break in our engines. My father was an mechanical engineer and always said that no matter how well an engine is made, it should be broken in carefully for at least 500 miles. He said really high RPMS should be avoided, that it should not be towed with and should be driven at varying RPM's.

My Diesel mechanic said that he likes to see diesel engines driven as I mentioned above for the first 500 miles and not towed with until there are 1000 miles on the engine.

How would you know?  An engine that isn't broken in properly isn't going to blow up, it's going to lose compression, throw a rod etc. the same as when any engine fails, the difference is that it may need a rebuild or replacement sooner than one that's broken in properly.  

I agree with Gard "I have a lot of money in my vehicles and don't want to spend any more than necessary to keep them running a long time. Proper maintenance and break in periods will ensure the longest life span."

edited for spelling

Sarcasm implied in my statement above. 

"How would you know?"  Exactly.  How would you know if improper break in caused the failure?  The type of failure likely to be cause by not following break in procedures will probably show late in the service life of the engine anyway.  Not to mention how many people actually keep a vehicle that long to start with? (that trend might change with fuel prices though)  Ive built a few engines in my younger days, this topic is hardly foreign to me. 

Modern engines are much better than they used to be, generally its not the engine that needs 'breaking in' before towing, its the rear end.

However, generally I follow break in procedures for all my equipment, motorcycle to trucks, but if I needed my new truck to go to work in the same situation the OP stated I would not hesitate to use the truck.

I wasn't trying to be sarcastic, I was just asking how you would know.  The point I was trying to make is that in the life of our engines, there are a few things in our control to help them last longer, break in is one of them and maintenance is the other.   There are of course things that can happen to an engine that are beyond our control like a faulty injector washing down a cylinder in a diesel engine, or weaknesses when the engine was built.

Even though the manufacturing of engines has improved there is still friction and parts that need to seat properly, so in my opinion, a proper break in is worth the time and effort and is still needed. 

Roperchick, I hope your husband realizes how fortunate he is to have such a well versed and knowledgeable wife. I've worked with some professional mechanics with less knowledge and common sense than you. Good job.

 I run my vehicles as long as they are viable, regardless of mileage or age. I can't afford constant replacements. My proactive maintenance is necessary. If I traded every few years, long life spans and break in periods would be a moot point. Purchase the best lubricants, treat the machinery with respect and observing a rigorous maintenance schedule, are the keys to a long lived and reliable vehicle.

Gard