How many miles does the Hemi motor need to be broke in?? 5k? What is your observation?

 

I have heard a few guys here say around 10K, I am not sure myself as I only have around 1400miles on mine so far.

 

My mpg leveled out after about 12K miles. To me, that would indicate that the motor had a chance to fully "break-in" by that time.

 

What is your avg MPG if you don't mind me asking?

 

I think the most important period for your break in is the first couple of hours.

 

My MPG was abysmal to start with at about 11-12mpg. That was due to constant stop and go driving in terrible traffic. It gradually went up to 13-14 in the same traffic. On highway jaunts I averaged about 17-18 at speeds of 75-80. My best was a little over 20mpg when I was taking backroads and cruising at about 55-60. My overall mixed driving after I moved out of South Florida was about 17. Of course this is with the non MDS Hemi.

My wife has the MDS Hemi in her JGC that we traded my truck for and we routinely see 20+ mpg. Granted there is a lot less weight, btu the overall gearing also keeps the rpm's up over my truck.

 

Yes, break-in does occur in short order. I was just explaining what I saw in relation to MPG

 

After about 10k mine leveled out at around 16mpg. Also, from what Ive been told, after about 10k is when you start seeing all your hp from the engine come out. I've heard this from the dealership, and from one of my uncles. He told me that when he took his 02' Viper down one of the guys in charge of righting up all the maintenace charts (a maintenace advisor?) told him that there was a limiter on most of the engines for the first 10k that slowly releases your hp so you dont damage the engine right away, a different dealer told me the same thing with my HEMI, and one of my friends who works for toyota said the samething is done with thier cars. Now I dont know if they are just blowing smoke in my face or what but everytime I take it down to have some maintenace done it always seems to get a little bit more of a "get-up-and-go" to it.

 

The quality control check for every engine is to fill them with oil and red line them before they ever leave the factory...granted this is only for a few seconds but there is also a limiter built into the Ram's at 105 MPH so there is really little chance of the average driver redlining the engine and damaging it. I believe the break in process is immediate and the first twenty miles are probably the most important.

 

Im not talking about that limiter, all it does is govern your speed. Redlining your motor and releasing horsepower have nothing to do with each other either. Like I said I dont know weather or not they mere just messing with me or what but hearing it from 3 different sources sounds kind of convincing to me, and why else would they do updates/re-flash your computer when you take it down to get any work done to your vehicle at the dealership?

Also why would you want to run the crap out of a new vehicle that only has about 5-10 miles on it? That just sounds like a stupid thing to do. Everything have been taught and everyone I know that knows anything about cars/trucks have all said that you never run it at full throttle right away, you wait a while ususally the first 500-1000 miles to break it in before you run it like it was meant to be ran so you dont burn anything up.