Forum Discussion

nomad297's avatar
nomad297
Explorer
Sep 13, 2014

4,000 - 4,200 RPM?

I have a 2004 Chevrolet 2500HD with the 6.0 and 4.10 rear with about 80,000 miles on it. This is what I use to pull my 8,000# travel trailer. I have kept it well-maintained and it still seems to work like it did when it was new.

My question is, how much wear and tear would I put on it if I let it run at 4,000 to 4,200 RPM up grades to maintain 55 MPH? My habit is to try and keep it around 3,000 RPM and let it decide how much it will slow down by the time I reach the top of the grade, but I would be much less of an annoyance to those behind me if I felt more comfortable letting it run at 4,000 to 4,200 RPM, but it just sounds scary when the motor is screaming at those high RPMs.

I think the motor's peak horsepower of about 300 is obtained at around 4,000 RPM, but does that mean it is ok to run it there? What are your opinions -- expert, or not?

Thank you,

Bruce
  • If you have never exceeded 3K you are going to have a broad grin on your face at 4K.
  • While my 6.0 screams and sucks gas at 4,200 rpm, that is the engines sweet spot on steep grades. I have never had issues with engine Temps, but do keep eye on transmission temp. The engine is made to handle the rpms. On steep grades I found it is best to lock the transmission to third gear on the steepest grades and maintain the peak torque at 4200 to 4500 rpms and I can maintain about 50mph on 5 to 7 percent grades with my 12k fiver. The trick is to maintain rpm, be patient and not allow the transmission to jump between gears or downshift. With the 2004, you may have, or will have a bit more of a challenge without the 6sp transmission in the newer models.
    Some will say get a diesel, but that is not pertinent to the OP questions.
  • Sport45 wrote:
    nomad297 wrote:
    My tach goes to above 5,000 with no red line. Does this mean I am safe taking it all of the way up there?

    Bruce


    Go ahead and punch it. The rev limiting will be handled by the computer. As mentioned it will run all day long at 4 - 4.2k. Just watch the temperature. As long as it's not climbing any faster than the gas gauge is dropping you'll be okay. :)


    I think my fear of high RPMs goes back to 1980 when I was messing around with a 90cc Yamaha motorcycle. Showing off, I was cranking the throttle up and down, getting higher and higher on the RPMs, when it finally went "BANG". It blew the spark plug out of the head into oblivion. I never did fix that bike.

    Bruce
  • nomad297 wrote:
    My tach goes to above 5,000 with no red line. Does this mean I am safe taking it all of the way up there?

    Bruce


    Go ahead and punch it. The rev limiting will be handled by the computer. As mentioned it will run all day long at 4 - 4.2k. Just watch the temperature. As long as it's not climbing any faster than the gas gauge is dropping you'll be okay. :)
  • transamz9 wrote:
    The 6.0 likes to run at the higher rpm. If you have been keeping it at 3000 this whole time then you don't know what your truck can do. Yes, it will be louder and to a lot of us annoying but it won't hurt it to run @ 4-4500 to pull the hills. Let it run.;)


    Thanks for your opinion.

    This is the kind of thing I'm needing to hear, but from more than just one person. I really would like to get the RPMs up there and feel good about it.

    I guess this is pretty much what everybody has stated so far.

    Bruce
  • The 6.0 likes to run at the higher rpm. If you have been keeping it at 3000 this whole time then you don't know what your truck can do. Yes, it will be louder and to a lot of us annoying but it won't hurt it to run @ 4-4500 to pull the hills. Let it run.;)
  • eHoefler wrote:
    As long as you are not beyond the red line on the tach, run it. They are designed to build peak torque at a certain RPM, run it there, it will be much happier and than trying to lug it.


    My tach goes to above 5,000 with no red line. Does this mean I am safe taking it all of the way up there?

    Bruce
  • Peak HP is at 4400RPM and peak torque is at 4000RPM. It shouldn't be any problem to run the engine there, especially when it is only on the hills.
  • As long as you are not beyond the red line on the tach, run it. They are designed to build peak torque at a certain RPM, run it there, it will be much happier and than trying to lug it.