Those that have tuned or programmed

Could be the more sustainable torque/power numbers are those that are made for medium duty applications ... so for the 6.7 Cummins and Powerstroke the number is around 750/330 torque/power as compared to the pick up truck ratings.


Edit: our Peterbilt doesn’t provide enough water cooling to prevent defueling on a hot day and the 15 litre Cat makes 550 crankshaft hp .The comparatively small rad on my pick up is going to have its work cut out for it trying to deal with 475 HP.

4x4ord wrote:


I know the Cat in my 07 Peterbilt will defuel when it gets too hot on a long hard pull. I suspect my Ford will defuel if ever gets too hot and I hope the Cummins will as well. I see that as a good thing. When TFL pulled 30,000 lbs up to the Eisenhower tunnel I wouldn’t call that a short burst of HP.

As I said, all modern diesels will defuel. Some more than others especially of they have a lot of power. This is one reason why I never care about stock power numbers and those that gloat about them because they don't know any better. Just because a truck has x hp, doesn't mean you are getting that horsepower all the time especially under sustained conditions.

The other other thing is, people believe that a certain condition will force a diesel A to defuel X amount of horsepower, then the very same conditions will force diesel B to defuel the same X amount of horsepower. This is false and it depends on how "hot" the initial power level is.

For example, manufacturers of diesel A may want to post the highest power levels possible for marketing so they post 400 hp even though it cannot sustain that power for very long. So they tune their engine to make the most power possible, and then have the ECU back it off as needed. This is all perfectly legit using SAE standards. So under towing conditions, engine A may need to defuel to 350 hp depending on many variable such as barometric pressure, turbo speeds, trans temps, EGT's and so on. Hotter ambient temps such as 90F exacerbates this issue making it defuel even more than it would at lower temps.

Then you have the manufacturer of diesel B who may want to give their customer sustained numbers so they tune their engine to 350 hp even though can easily do the same power levels as engine A and back it down as needed. Since engine B is tuned for sustained power, it does not need to defuel and cut power in the same type of conditions. It may eventually need to defuel, but it will take a lot more to get it to that point of cutting power from the stock power levels since the stock tune was very conservative to begin with.

Generally, when someone says that a truck feels more labored with a load, then that is a clear sign that it is in the category of engine A. Adversely, when someone says that an engine does not feel that it has to work harder with more load or that higher loads do seem to effect it as much, then it is in category B.

I will also point out that what is happening in the engine A example is essentially how it is with my tunes except I back it down myself instead of the computer. Unloaded, I keep it on my highest power level. Towing, I will lower the power levels(defuel) on the fly depending the load and temps. Just because it is safe for me to tow 12k lbs in 40F at 500 hp at 50F, does not mean I can do the same at 95F.

There are many variables that come into play that you have to be mindful of. Hence the reason why I tell people that do not have gauges or want the computer to do all the work for them to just leave it in the lowest power level possible. Higher power levels are for those who have gauges, know what they are doing, and know what are the limits of the truck. There is a reason why heavy duty trucks had so many gauges and the professional drivers had to know what those gauges meant back in the day. Now, with computer controlled engines, it is not as important to have all the gauges since the computer will keep the truck within safe limits so the need for professional drivers is becoming a thing of the past and are being replaced by steering wheel holders.

I used my programmer just to adjust for the gear ratio change, lower the shift points, and firm up the transmission shifting.
No need for additional performance. What will it save you really on a 5 hour drive?

If it had a fuel economy setting I may have considered it.

Super Dave… Hopefully you have a pyrometer so you can watch the exhaust heat. Is economy less power than Tow? Tow should be safe so start with that but I would also try economy, just out of curiosity. I had a Diablo sport stack on my 03, 6 speed truck. Tow was 60 and economy was 100 hp. With a bigger towing turbo and all the air and exhaust mods I could run the 100 easily. The 100 was actually a better towing tune than the 60 and i got better mpg with the 100. Wwatch the gauges and try economy and tow and see which one you like better. Watch out for clutch or transmission slipping and also see which one provides better drive ability. Craig

ShinerBock wrote:
Argument? I am just stating facts that even the new 475 crank hp Powerstroke is not a sustained power level and will defuel when temps get too hot. All diesel engine will do this to a certain extent. If you don't believe me, go ask a Ford engineer or the guys at Calibrated Power Solutions who made that tuned towing comparison video Fish posted a while back. Heck, they even state it in one of the videos in that series.

I am sorry if you can't handle the truth and think it is an argument. I would suggest to stop quoting me like you did in this thread if that is not something you want to hear. Truth is, some manufacturers post sustained power numbers and some post quick burst power numbers that cannot be sustained over long periods of time under heavy load.

Better yet, go buy an Edge CTS monitor and watch EGT, commanded fuel pressure, actual fuel pressure. You will see fuel pressure starts to drop (defuelinng) when EGTs get too high.

I know the Cat in my 07 Peterbilt will defuel when it gets too hot on a long hard pull. I suspect my Ford will defuel if ever gets too hot and I hope the Cummins will as well. I see that as a good thing. When TFL pulled 30,000 lbs up to the Eisenhower tunnel I wouldn’t call that a short burst of HP.

Here is a good video from Calibrated Power Solutions on towing at higher power levels. They go over what to watch and what supporting mods are needed to tow at higher power levels. Keep in mind that they are talking wheel horsepower not crank horsepower.

Towing in the race tune

Edd505 wrote:

ShinerBock wrote:

4x4ord wrote:
That sounds wonderful. If the Ram grill area is large enough to supply cooling for 475 sustained rear wheel HP we likely haven’t seen the end of the hp increases from the factory trucks.

You are forgetting about emissions again and how they play into the sustained performance and efficiency of a stock engine.

I could not sustain 475 hp at the wheels on stock turbo with emissions equipment.

Hummm 2015 Ford stock 440HP tuner 40HP bump on a stock engine with all emissions intact.

You are mixing wheel horsepower with crank horsepower. My 475 hp at the wheels is 546 hp at the crank with the standard 15% drivetrain loss. A 440 hp at the crank with another 40 hp is 480 hp at the crank which is about 408 hp at the wheels with a 15% drivetrain loss.

Argument? I am just stating facts that even the new 475 crank hp Powerstroke is not a sustained power level and will defuel when temps get too hot. All diesel engine will do this to a certain extent. If you don't believe me, go ask a Ford engineer or the guys at Calibrated Power Solutions who made that tuned towing comparison video Fish posted a while back. Heck, they even state it in one of the videos in that series.

I am sorry if you can't handle the truth and think it is an argument. I would suggest to stop quoting me like you did in this thread if that is not something you want to hear. Truth is, some manufacturers post sustained power numbers and some post quick burst power numbers that cannot be sustained over long periods of time under heavy load.

Better yet, go buy an Edge CTS monitor and watch EGT, commanded fuel pressure, actual fuel pressure. You will see fuel pressure starts to drop (defuelinng) when EGTs get too high.

ShinerBock wrote:

4x4ord wrote:
That sounds wonderful. If the Ram grill area is large enough to supply cooling for 475 sustained rear wheel HP we likely haven’t seen the end of the hp increases from the factory trucks.

You are forgetting about emissions again and how they play into the sustained performance and efficiency of a stock engine.

I could not sustain 475 hp at the wheels on stock turbo with emissions equipment.

Hummm 2015 Ford stock 440HP tuner 40HP bump on a stock engine with all emissions intact.

Whatever Shiner. Everything has got to be an argument with you .... I'm sure you're aware of the significant changes made to the 2020 Powerstroke. Steel pistons; stronger connecting rods and main bearings; stiffened block; redesigned heads to provide better cooling; new VGT turbo; new injectors; 36000 psi fuel injection system; split stream piston cooling jets; lowered compression ratio; redesigned 10r140 transmission. Is your theory that this was done to give a little short burst of power so they could maintain bragging rights for highest in class HP? I'll put my confidence in a factory Cummins or Powerstroke having sustained HP ratings before believing the guy who throws a tuner and turbo on his truck and claims he has 475 sustained rear wheel HP.