V10 RPM November 21, 2020, 07:01:08 pm I have a question about engine rpm while climbing a grade. I read that max torque was achieved at about 3500 rpm and a limiter was set to about 5500 rpm. Do these values sound about right. While climbing a grade is it reasonable to select a gear that keeps the engine rpm at around 3500 rpm? Would you ever run the engine to 5500 rpm and if you did would that create a problem?Randy
Re: V10 RPM Reply #1 – November 21, 2020, 08:05:58 pm I suggest you let the engine and transmission figure it out. They called "automatic transmissions" for good reasons.For hill climbing, what counts is power, not the RPM of the full throttle torque peak, as the transmission gears adjust the torque sent to the rear wheels. I let the engine and tranny do the work, while I press on the accelerator to select the best compromise between engine noise speed (which are personal preferences, generally speaking).
Re: V10 RPM Reply #2 – November 21, 2020, 08:20:20 pm Quote from: Eric Greenwell - November 21, 2020, 08:05:58 pmI suggest you let the engine and transmission figure it out. They called "automatic transmissions" for good reasons.For hill climbing, what counts is power, not the RPM of the full throttle torque peak, as the transmission gears adjust the torque sent to the rear wheels. I let the engine and tranny do the work, while I press on the accelerator to select the best compromise between engine noise speed (which are personal preferences, generally speaking).Couldn't have said it better. Your 2018 chassis has the 6-speed transmission and a V10 with HP peak at 4,250 rpm, a torque peak at 3,250 rpm, and can run at max rpm without harm. Just put your foot down, let the chassis do the thinking, and enjoy the ride.Charles
Re: V10 RPM Reply #3 – November 21, 2020, 08:45:54 pm And how best to handle going down said grade? 🤔
Re: V10 RPM Reply #4 – November 21, 2020, 09:00:01 pm Quote from: HiLola - November 21, 2020, 08:45:54 pmAnd how best to handle going down said grade? 🤔Put it in Tow-Haul, it works too. If you don't have it put it in 2nd.Charles 2 Likes
Re: V10 RPM Reply #5 – November 21, 2020, 09:26:10 pm RandyEven though it's called "Automatic" there's no reason to not use it like a stick shift. Let your engine do the braking on those downhill stretches by down shifting to a speed you are comfortable with. My father was a long haul driver and I am his son! 1 Likes
Re: V10 RPM Reply #6 – November 21, 2020, 10:56:29 pm "Let your engine do the braking on those downhill stretches by down shifting to a speed you are comfortable with."But do it before you end up going too fast for comfort. 2 Likes
Re: V10 RPM Reply #7 – November 22, 2020, 05:09:06 am Def use low gear down steepGrades - don’t want the breaks to melt and burn.
Re: V10 RPM Reply #8 – November 22, 2020, 09:27:44 am I have heard, can't remember from whom, that your max power for climbing hills was achieved where the the RPM graph lines for torque and horsepower cross. I believe this is approximately 3500 RPMs. Anything above this, does little benefit. Of course going downhill is different, use your tow haul and let transmission decide what is best with occasional breaking by you when needed. 1 Likes
Re: V10 RPM Reply #9 – November 22, 2020, 07:36:11 pm Quote from: Ross and Beverly Taylor - November 22, 2020, 09:27:44 amI have heard, can't remember from whom, that your max power for climbing hills was achieved where the the RPM graph lines for torque and horsepower cross. Keep in mind the torque curve and the horsepower curve contain exactly the same information (power = torque x RPM). For that reason, the crossing point of a torque/horsepower vs rpm graph is an artifact of the way the graph is drawn, because you have to have two vertical axis: one in torque, one in horsepower. Keeping the torque axis scale constant (say 0 to 500 ftlbs), but changing the horsepower scale from 0-500hp to 0-600hp, will raise the RPM of the crossing point, showing the crossing point is not a number important to the engine.So, going uphill, let the engine and transmission work their engineering magic, and just press on the gas pedal until you are going fast enough, and the sound isn't too loud to annoy you.Going downhill, follow the advice from the other posters
Re: V10 RPM Reply #10 – November 23, 2020, 04:17:15 pm So, going uphill, ...just press on the gas pedal until you are going fast enoughAh ha! I have a defective gas pedal, I have never gone as fast as I want uphill. I was making almost 50 up the long slog of Eisenhower Pass. Just before the tunnel, I got trapped behind a truck going maybe 15. I think I was able to get back to 25.
Re: V10 RPM Reply #11 – November 23, 2020, 04:34:07 pm "...long slog of Eisenhower Pass."I hear what you're saying, I too have misread the traffic and was unable to get around slow vehicles on that very pass. Try to not lose your momentum under those conditions, you can never get it back.
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Topic: V10 RPM (Read 392 times)
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