You choose - loaded gas or basic diesel?

otrfun wrote:

4x4ord wrote:
Horsepower is horsepower. When talking engines ... torque is horsepower as well. An engine cannot produce torque without running. When it is running and producing torque there you have all three; torque, rpm and horsepower. When we talk about an engines torque rating we are referring to the maximum torque the engine makes and it is specified at an rpm ... Torque @ rpm is equal to power. The manufactures give torque rating @ an rpm and further define the powerband of their engine by providing the max HP @ a certain rpm. Together this information forms a power graph in an understanding persons mind and they will have a very good idea of it pulling characteristics, especially if they consider the gear ratios of transmission along with the final drive ratio and tire size all together. Many people have the misconception that diesels produce more torque than gasoline engines. In fact the opposite is true. Torque and therefore horsepower come from the fuel. Gasoline requires less air per unit of energy than does diesel to burn therefore more torque and power can be achieved per liter of engine displacement with the gasoline engine. Diesel lend themselves very nicely to turbocharging, which, in a way, increases the displacement of the engine and therefore allows for much more fuel per rev to be injected. This increased fuel per rev increases the torque of the engine. With the new technology available gasoline engines with direct injection can also be easily supercharged. If you talk turbocharged gasoline vs turbocharged diesel the gasoline engine will make more torque per engine displacement than will the diesel. And if you talk naturally aspirated diesel vs naturally aspirated gasoline engines the gasoline engine produces much more torque again. It is the turbo that is responsible for the high torque output of modern diesels.

Wow, well said. Very informative. My whole point in this thread was to explain the implications of varying the torque and HP curves of any given engine design. How these changes effect realworld driveability. Some folks here seem to ignore these implications or simply don't understand it. Simply saying horsepower is the ultimate panacea for every power issue is not a very convincing argument in my book. Again, 4x4ord, thanks for the excellent post!

If you are going to try to paraphrase my statement, at least get them right. I never said Horsepower is the panacea for every power issue.

I was very careful to say that horsepower is the only rating that is used to calculate how fast you can go. Goodness man, if you can't even understand what I write, what is the point? :S

I fear I have failed to take Mr. Twains advice on who to argue with. Now look at me, I have fallen into the Ad Hominem trap!

4x4ord wrote:
Horsepower is horsepower. When talking engines ... torque is horsepower as well. An engine cannot produce torque without running. When it is running and producing torque there you have all three; torque, rpm and horsepower. When we talk about an engines torque rating we are referring to the maximum torque the engine makes and it is specified at an rpm ... Torque @ rpm is equal to power. The manufactures give torque rating @ an rpm and further define the powerband of their engine by providing the max HP @ a certain rpm. Together this information forms a power graph in an understanding persons mind and they will have a very good idea of it pulling characteristics, especially if they consider the gear ratios of transmission along with the final drive ratio and tire size all together. Many people have the misconception that diesels produce more torque than gasoline engines. In fact the opposite is true. Torque and therefore horsepower come from the fuel. Gasoline requires less air per unit of energy than does diesel to burn therefore more torque and power can be achieved per liter of engine displacement with the gasoline engine. Diesel lend themselves very nicely to turbocharging, which, in a way, increases the displacement of the engine and therefore allows for much more fuel per rev to be injected. This increased fuel per rev increases the torque of the engine. With the new technology available gasoline engines with direct injection can also be easily supercharged. If you talk turbocharged gasoline vs turbocharged diesel the gasoline engine will make more torque per engine displacement than will the diesel. And if you talk naturally aspirated diesel vs naturally aspirated gasoline engines the gasoline engine produces much more torque again. It is the turbo that is responsible for the high torque output of modern diesels.

Wow, well said. Very informative. My whole point in this thread was to explain the implications of varying the torque and HP curves of any given engine design. How these changes effect realworld driveability. Some folks here seem to ignore these implications or simply don't understand it. Simply saying horsepower is the ultimate panacea for every power issue is not a very convincing argument in my book. Again, 4x4ord, thanks for the excellent post!

4x4ord wrote:
Horsepower is horsepower. When talking engines ... torque is horsepower as well. An engine cannot produce torque without running. When it is running and producing torque there you have all three; torque, rpm and horsepower. When we talk about an engines torque rating we are referring to the maximum torque the engine makes and it is specified at an rpm ... Torque @ rpm is equal to power. The manufactures give torque rating @ an rpm and further define the powerband of their engine by providing the max HP @ a certain rpm. Together this information forms a power graph in an understanding persons mind and they will have a very good idea of it pulling characteristics, especially if they consider the gear ratios of transmission along with the final drive ratio and tire size all together. Many people have the misconception that diesels produce more torque than gasoline engines. In fact the opposite is true. Torque and therefore horsepower come from the fuel. Gasoline requires less air per unit of energy than does diesel to burn therefore more torque and power can be achieved per liter of engine displacement with the gasoline engine. Diesel lend themselves very nicely to turbocharging, which, in a way, increases the displacement of the engine and therefore allows for much more fuel per rev to be injected. This increased fuel per rev increases the torque of the engine. With the new technology available gasoline engines with direct injection can also be easily supercharged. If you talk turbocharged gasoline vs turbocharged diesel the gasoline engine will make more torque per engine displacement than will the diesel.

It doesn't matter, some will not listen. You are absolutely right about all of that. I never once said that it was as simple as picking the engine with the most horsepower and thinking that will fit your needs. The horsepower rating however is THE rating of how much work the engine can produce over time and the only of the two ratings to look at when trying to figure out top speed.

I just get a little too wound up when people start spouting off complete nonsense I guess ( I wasn't referring to you 4x4).

Horsepower is horsepower. When talking engines ... torque is horsepower as well. An engine cannot produce torque without running. When it is running and producing torque there you have all three; torque, rpm and horsepower. When we talk about an engines torque rating we are referring to the maximum torque the engine makes and it is specified at an rpm ... Torque @ rpm is equal to power. The manufactures give torque rating @ an rpm and further define the powerband of their engine by providing the max HP @ a certain rpm. Together this information forms a power graph in an understanding persons mind and they will have a very good idea of it pulling characteristics, especially if they consider the gear ratios of transmission along with the final drive ratio and tire size all together. Many people have the misconception that diesels produce more torque than gasoline engines. In fact the opposite is true. Torque and therefore horsepower come from the fuel. Gasoline requires less air per unit of energy than does diesel to burn therefore more torque and power can be achieved per liter of engine displacement with the gasoline engine. Diesel lend themselves very nicely to turbocharging, which, in a way, increases the displacement of the engine and therefore allows for much more fuel per rev to be injected. This increased fuel per rev increases the torque of the engine. With the new technology available gasoline engines with direct injection can also be easily supercharged. If you talk turbocharged gasoline vs turbocharged diesel the gasoline engine will make more torque per engine displacement than will the diesel. And if you talk naturally aspirated diesel vs naturally aspirated gasoline engines the gasoline engine produces much more torque again. It is the turbo that is responsible for the high torque output of modern diesels.

OhhWell wrote:
No, I am pretty well grounded in the real world. You know, physics and all that. You keep ignoring physics and other real world stuff like that. I think at this point, even die hard diesel fanatics are face-palming.

I don't see anyone pulling trailers with a john deer on the highway anymore than I see any big rigs screaming along at 12,000 RPM burning gasoline.

Horsepower is horsepower and that is how we rate the amount of work done over time. That is the real world and Caterpillar and Cummins understand that perfectly well.

I'll let my posts stand. Just stating you know physics, and that horsepower is horsepower, and that Caterpillar/Cummins know their stuff, unfortunately is not a very powerful or convincing debate tactic.

goducks10 wrote:
High HP, low TQ for lighter vehicles.
High TQ, low HP for heavier vehicles.
Done.

Thank you! Well put!!

No, I am pretty well grounded in the real world. You know, physics and all that. You keep ignoring physics and other real world stuff like that. I think at this point, even die hard diesel fanatics are face-palming.

I don't see anyone pulling trailers with a john deer on the highway anymore than I see any big rigs screaming along at 12,000 RPM burning gasoline.

Horsepower is horsepower and that is how we rate the amount of work done over time. That is the real world and Caterpillar and Cummins understand that perfectly well.

High HP, low TQ for lighter vehicles.
High TQ, low HP for heavier vehicles.
Done.

OhhWell wrote:

otrfun wrote:

OhhWell wrote:

otrfun wrote:

OhhWell wrote:

otrfun wrote:

OhhWell wrote:

otrfun wrote:
As they say, torque does the real work, not horsepower.

Who in the heck says that? Torque is a measure of force and horsepower is a measure of WORK.

You can multiply torque through gearing. You can't increase your horsepower through anything besides upgrading the powerplant.

Definition of horsepower

I get your technical point; however, I believe you missed my point.

It's just a case of semantics. Notice my use of the word "real" work. I'm talking about work as defined by the average person:

"activity involving physical effort done in order to achieve a purpose or result"

If someone needs to haul or tow a lot, and wants to "achieve a purpose or result", which engine would be the better choice?

1. An engine with 400 HP and 200 ft. lbs. of torque.

2. An engine with 200 HP and 400 ft. lbs. of torque.

I think most would choose engine #2. Why? Because in the above scenario an abundance of torque allows them to "work" at "achieving a purpose or result" much easier than an abundance of horsepower.

I would pick engine 1 any day of the week. I might actually have to climb a hill at some point. I'm assuming that in this scenario, the same exact transmission isn't forced on both engines?

You're jokin', right?! If not, is it possible you have horsepower and torque confused? There's a reason why diesel engines are so popular--it's NOT because they have horsepower--it's because they have TORQUE. Again, torque pulls the trailers, hauls the goods, does the work in the realworld. If horsepower was doing all these great things why don't we see Indy 500-type engines powering big trucks? They're small, lightweight, and they produce 700+ horsepower. There's a reason why you'll never see one in a big truck--it's because they have very little torque.

P.S. I see your point about gearing down to increase torque. However, if this was an efficient process, can you explain why we don't see 700+ horsepower Indy 500-type engines powering big trucks?

I do not have horsepower and torque confused. I was wondering if perhaps you did? Torque doesn't pull ANYTHING is it a measure of force. It is a very important measurement but doesn't have squat to do with acceleration or top speed. If these high torque diesel engines could rev as high as gassers do, they would have insane amounts of horsepower.

The reason you don't see Indy Car engines in big trucks is due to longevity and fuel economy. Big trucks and diesel engine manufacturers don't spout out Torque numbers except (it appears) to the light duty truck consumers. Even there we are starting to see a horsepower push and race. Top speed calculations don't take torque into consideration at all, incline or not, it is all horsepower.

Luckily, diesel engines these days have more than enough horsepower as well so it's really all good. Your scenario you posed was too extreme. I wouldn't want to tow a heavy load up a decent hill with only 200hp no matter what the fuel type. You can scream TORQUE all you want but it isn't going to go very fast.

I totally and respectfully disagree. Please reread my previous posts referencing HP = Torque x RPM /5252. Using this formula, please explain why you would choose a 400 HP, 200 ft. lb. of torque engine that has to rev over 10,000 RPM as a practical truck engine. Until you address this, then I don't believe you have a credible argument.

I'm sorry if the torque and horsepower numbers you came up with off of the top of your head require RPMs that are next to unheard of for the high horsepower option. I should have thought of that but just took it at face value. I guess you really got me! :R BUT, then again, it was your fictitious engie so therefore, it must be able to rev that high since you classified it as a 400HP engine! I guess you didn't actually get me.

I could see maybe bringing it to 7k RPM or so however because that is not unheard of for a gas engine and I'm still going to go faster up the hill than with the 200 HP dog.

I don't think it makes your odd position that torque is everything any more valid unfortunately. I have driven High torque, low horsepower engine equipped vehicles before. Everything is well and good and the feeling of power is great until you get to a point and then.... well, there is nothing left. Horsepower is horsepower and only horsepower will determine how fast you are going to pull a load.

Those numbers are far from fictitious. There are many high performance, naturally aspirated engines in Europe and Japan that have similar HP/torque numbers.

Your argument that the only reason they don't use Indy 500 engines in trucks is because of longevity and fuel economy completely ignores and skirts around the point I'm trying to make. An Indy 500 engine has approx. 650-700 HP. It makes this HP at 12,000 RPM!! However, its torque output is only about 300-350 ft. lbs. at just under 12,000 RPM. Yes, you can gear it down to get more torque to the pavement, but the WHOLE point is---it's totally impractical to drive an engine that has to constantly rev from idle to 12,000 RPM for every shift of the transmission to produce any usable, realworld output (both torque and HP). That is why you'll NEVER see this type of engine in a truck. In your discussion here, you completely ignore the whole realworld drivability issue of torque vs. HP.

otrfun wrote:

OhhWell wrote:

otrfun wrote:

OhhWell wrote:

otrfun wrote:

OhhWell wrote:

otrfun wrote:
As they say, torque does the real work, not horsepower.

Who in the heck says that? Torque is a measure of force and horsepower is a measure of WORK.

You can multiply torque through gearing. You can't increase your horsepower through anything besides upgrading the powerplant.

Definition of horsepower

I get your technical point; however, I believe you missed my point.

It's just a case of semantics. Notice my use of the word "real" work. I'm talking about work as defined by the average person:

"activity involving physical effort done in order to achieve a purpose or result"

If someone needs to haul or tow a lot, and wants to "achieve a purpose or result", which engine would be the better choice?

1. An engine with 400 HP and 200 ft. lbs. of torque.

2. An engine with 200 HP and 400 ft. lbs. of torque.

I think most would choose engine #2. Why? Because in the above scenario an abundance of torque allows them to "work" at "achieving a purpose or result" much easier than an abundance of horsepower.

I would pick engine 1 any day of the week. I might actually have to climb a hill at some point. I'm assuming that in this scenario, the same exact transmission isn't forced on both engines?

You're jokin', right?! If not, is it possible you have horsepower and torque confused? There's a reason why diesel engines are so popular--it's NOT because they have horsepower--it's because they have TORQUE. Again, torque pulls the trailers, hauls the goods, does the work in the realworld. If horsepower was doing all these great things why don't we see Indy 500-type engines powering big trucks? They're small, lightweight, and they produce 700+ horsepower. There's a reason why you'll never see one in a big truck--it's because they have very little torque.

P.S. I see your point about gearing down to increase torque. However, if this was an efficient process, can you explain why we don't see 700+ horsepower Indy 500-type engines powering big trucks?

I do not have horsepower and torque confused. I was wondering if perhaps you did? Torque doesn't pull ANYTHING is it a measure of force. It is a very important measurement but doesn't have squat to do with acceleration or top speed. If these high torque diesel engines could rev as high as gassers do, they would have insane amounts of horsepower.

The reason you don't see Indy Car engines in big trucks is due to longevity and fuel economy. Big trucks and diesel engine manufacturers don't spout out Torque numbers except (it appears) to the light duty truck consumers. Even there we are starting to see a horsepower push and race. Top speed calculations don't take torque into consideration at all, incline or not, it is all horsepower.

Luckily, diesel engines these days have more than enough horsepower as well so it's really all good. Your scenario you posed was too extreme. I wouldn't want to tow a heavy load up a decent hill with only 200hp no matter what the fuel type. You can scream TORQUE all you want but it isn't going to go very fast.

I totally and respectfully disagree. Please reread my previous posts referencing HP = Torque x RPM /5252. Using this formula, please explain why you would choose a 400 HP, 200 ft. lb. of torque engine that has to rev over 10,000 RPM as a practical truck engine. Until you address this, then I don't believe you have a credible argument.

I'm sorry if the torque and horsepower numbers you came up with off of the top of your head require RPMs that are next to unheard of for the high horsepower option. I should have thought of that but just took it at face value. I guess you really got me! :R BUT, then again, it was your fictitious engie so therefore, it must be able to rev that high since you classified it as a 400HP engine! I guess you didn't actually get me.

I could see maybe bringing it to 7k RPM or so however because that is not unheard of for a gas engine and I'm still going to go faster up the hill than with the 200 HP dog.

I don't think it makes your odd position that torque is everything any more valid unfortunately. I have driven High torque, low horsepower engine equipped vehicles before. Everything is well and good and the feeling of power is great until you get to a point and then.... well, there is nothing left. Horsepower is horsepower and only horsepower will determine how fast you are going to pull a load.