trucks HP vs Tork

[mlh]

A tuner or chip will give a few extra horsepower and torque in a naturally aspirated engine. If it has a turbo or twin turbos the power is almost unlimited up to what the engine will stand and turbo will produce. But that is true with a Diesel engine too. I can load up a different tune that I already have in my tuner and have 350 extra rear wheel horsepower. Rear wheel horsepower is different from engine horsepower. You add 22% to get engine horsepower.
Lynwood

[77cruiser]

A naturally aspirated engine will never produce the torque a turbo engine will gas or diesel. May produce the same HP but rpm will have to increase.

[mlh]

Originally Posted by 77cruiser

A naturally aspirated engine will never produce the torque a turbo engine will gas or diesel. May produce the same HP but rpm will have to increase.

And a turbo engine will always get better fuel mileage than a NA engine with the same horsepower. Says Bosch.
Lynwood

[JABURKHOLDER]

Originally Posted by glenshaeffer

I don't remember the name, but there is a chip you can get for gas engines that will boast foot pounds to be equal to diesels. I put one on a Dodge a pulled hills as good as diesels. My brother put on on his truck and said it made such a difference that he was out pulling diesels going up hill. You might nwant to check on it.

Most gassers have about half the torque of a diesel.
A chip that can double your torque ? Hmmmm

[AZMont]

I am also firmly in the diesel camp. Better hill climbing and fuel economy. Then, there is the exhaust brake. I used to own a 2000 F250 7.3L diesel with no exhaust brake. When I got my 2020 Ram 3500 HO diesel. I really learned to appreciate the safety of the exhaust brake. I'm pulling a 2015 RL3100 Monti that Cat Scales at #13,500 loaded.

[77cruiser]

No ex. brake on my 04 either, but now I have a 19 but haven't really tried it out yet. Came down Monarch pass a few years back with the 04 even at 25 mph brakes still got a bit warm.

[Dave W]

I agree that exhaust brakes are great. My '11 doesn't have one though it does have Tow/Haul and manual transmission shifting, both of which I use and have never had a hot brake situaltion on any of our trips.



Would I like an exhaust brake - for sure but a new truck is not in my future - unfortunately

[MT167]

The reason a diesel has more pulling power (torque) than a gasser is due to a longer stroke. Think of it this way, try to loosen a stubborn nut with a six inch ratchet, then try it with a twelve inch breaker bar. The ratchet will require less stroke but the breaker bar will be much easier.

[77cruiser]

More to do with 30 - 40 lbs. of boost than stroke.

[mlh]

The 6.7 Ford has a bore of 3.9 inches and a stroke of 4.25 inches.
Lynwood

[77cruiser]

Take the turbo off of any of them & you'll be about 200 hp & 300 ft. lbs.

[mlh]

Originally Posted by 77cruiser

Take the turbo off of any of them & you'll be about 200 hp & 300 ft. lbs.

That happened to me. I had a blown turbo hose in Montana of course going up a large hill called Bolder Hill. I was almost to the top when it went off like a shotgun. No power and I almost couldn’t see my camper for the smoke. There is a web cam where we were stopped. I still Google Bolder hill web cam Montana. Brings back old memories.
Lynwood

[kowbra]

Originally Posted by MT167

The reason a diesel has more pulling power (torque) than a gasser is due to a longer stroke. Think of it this way, try to loosen a stubborn nut with a six inch ratchet, then try it with a twelve inch breaker bar. The ratchet will require less stroke but the breaker bar will be much easier.

Well, yes or no, it depends on the engine design. Often true, especially on 6 cylinder diesels vs 8 cylinder gas.

But the real reason diesels have more torque starts with 2 differences in the fuel itself:
1. there is more energy in a pound of diesel than in a pound of gas.
2. diesel is slower burning. Slower burn means greater power extraction.

BECAUSE of the 2 primary differences in the fuel, diesel engines are designed differently. Primarily, they have a lot higher compression ratios. If a gas engine were to be designed with as high of compression ratios it would have to burn much higher octane gasoline (performance gas engines do but they are designed for high HP, high revs; typically not high torque).

Taking the above 2 categories together, you have an engine that inherently has more "pulling/staying power" (torque) even if the other design considerations were the same. IOW if you build an engine with similar bore and stroke and add tubos to both, etc, the diesel engine will have more torque.

Brad

[Theunz]

Diesels have a compression ratio of about 17 to 1 while gas engines are around 9 to 1, although with advances in modern fuel injection and electronics some high performance gas engines are up to around 12 to 1. It wasn’t long ago that even race cars didn’t have more than 13 to 1.
That high compression ratio is one of the reasons diesels are so heavy, as engine components similar to a gas engine just would not be able to stay together under the high stress loads that diesels operate under.

[mlh]

Originally Posted by kowbra

Well, yes or no, it depends on the engine design. Often true, especially on 6 cylinder diesels vs 8 cylinder gas.

But the real reason diesels have more torque starts with 2 differences in the fuel itself:
1. there is more energy in a pound of diesel than in a pound of gas.
2. diesel is slower burning. Slower burn means greater power extraction.

BECAUSE of the 2 primary differences in the fuel, diesel engines are designed differently. Primarily, they have a lot higher compression ratios. If a gas engine were to be designed with as high of compression ratios it would have to burn much higher octane gasoline (performance gas engines do but they are designed for high HP, high revs; typically not high torque).

Taking the above 2 categories together, you have an engine that inherently has more "pulling/staying power" (torque) even if the other design considerations were the same. IOW if you build an engine with similar bore and stroke and add tubos to both, etc, the diesel engine will have more torque.

Brad

Fords Ecoboost engines have about the same torque as their Diesel engine. The 2.7 has a little less and the 3.5 a little torque more per liter. They both are fairly low RPM engines. The 2.7 HP is 5750 RPM, or close to that. The Diesel HP is either 5000 or 5500 RPM. There isn’t much difference in either HP or Torque in either engine per liter.
Lynwood

[kowbra]

Originally Posted by mlh

Fords Ecoboost engines have about the same torque as their Diesel engine. The 2.7 has a little less and the 3.5 a little torque more per liter. They both are fairly low RPM engines. The 2.7 HP is 5750 RPM, or close to that. The Diesel HP is either 5000 or 5500 RPM. There isn’t much difference in either HP or Torque in either engine per liter.
Lynwood

Do you have a reference?
And, is the performance from the design of the engine or the turbo boost being used? ie, apples to apples?

Brad

[mlh]

Originally Posted by kowbra

Do you have a reference?
And, is the performance from the design of the engine or the turbo boost being used? ie, apples to apples?

Brad

All of this comes from Ford Motor web site. Then do a little simple math to find HP and torque per liter. So yes it is apples to apples.
Lynwood

[432bartman]

Originally Posted by mlh

Fords Ecoboost engines have about the same torque as their Diesel engine. The 2.7 has a little less and the 3.5 a little torque more per liter. They both are fairly low RPM engines. The 2.7 HP is 5750 RPM, or close to that. The Diesel HP is either 5000 or 5500 RPM. There isn’t much difference in either HP or Torque in either engine per liter.
Lynwood

I don't know where you're getting your information, but the new Ford 6.7 diesel makes 475 hp at 2600 RPM, and all it's available torque at 1600 RPM. The Ecoboost has no where near the torque of a diesel. All diesels make their torque low in the RPM spectrum.

[kowbra]

Originally Posted by mlh

All of this comes from Ford Motor web site. Then do a little simple math to find HP and torque per liter. So yes it is apples to apples.
Lynwood

I don't want to belabor this, but I was making the point that if engines are apples to apples in design of bore and stroke (and optionally using similar turbos) you will have more torque from a diesel; for the reasons I mentioned.

The Ford engines in question are not apples to apples even though some of the specs may be similar. For instance, at what RPMs are HP and torque delivered? What are the compression ratios and turbo boosts? What are each of the power band curves?

At the risk of getting overly technical, HP and torque are equal if both are made at 5400 RPM. Any engine that delivers its torque lower down will have more real world practical pulling power and a much flatter power curve than an engine that makes the same HP and torque higher up.

And how that relates to the rest of the thread? Due to the points I made in my prior post and in this one, diesel engines inherently make more torque at lower RPMs, and in practical terms that is beneficial to hauling a heavy load.

hth
Brad

[mlh]

The point I was making is, per liter the Ecoboost engine has about the same torque as Ford’s diesel. The 3.5 Ecoboost has 148.5 Torque per liter while the Diesel has 156.7 torque per liter. The diesel makes its peak torque at 1600 while the Ecoboost makes peak torque at 2500 and has 90% from 2000 to 5000. That is according to Ford.
Lynwood