Proud,

All valid points, but in the world of marketing and intense competition for your dollar, more is always going to be seen as better. The bigger the better, the more power the better. We might know the score here, but there's a ton of goofballs out there that don't (that thing got a Hemmay?)

The lines have long ago been blurred in regards to 1/2 ton, 3/4 ton, etc. Trucks really can't be thought of with those designations anymore. Now, anyone with some common sense would know not to pull a 5th-wheel with a "1/2 ton" truck, regardless of whether or not it could do it. But I think it gives the macho guys an extra sense of security knowing it can tow 10,000 pounds-plus.

I'm all for advancing fuel economy in pickups, and I think that's happening. I can't wait for a diesel offering in GM's 1500 line. I think it will be a very popular option, especially if it's priced to be worthwhile.

 

Excellent post.

When you get to the brass tacks of it, horsepower numbers are irrelevent when talking about regular trucks.

First, it's TORQUE that not only provides the "work" as you mentioned, but it's torque that provides acceleration and "feel" of power.

Second, and just as noteworthy, pickup trucks are governed to just around 100 to 110 mph, regardless of horsepower. Only exception is purpose built trucks like the Ram SRT-10 or the long dead Ford Lightning. Silverado SS is governed to under 110.

The 400+ horse Escalade's party stops at 107 mph. All regular Chevy trucks stop at 100.

Of course, if the price of a new vehicle is but a drop in the bucket of your vast wealth, you can void the warranty of your new vehicle and install an aftermarket chip. But there's probally a good reason why large trucks are governed so low in the 1st place.

 

Power is simply torque at speed. Torque is ALWAYS providing the work and the accleration (not sure what is meant by the "feel" of power). Engines produce torque when the explosions in each cylinder push the piston down and twist the crankshaft via a lever (connecting rod). The resulting power number is the torque generated at a given engine speed times that given speed. It is torque acting through the gears and to tires/ground that moves the vehicle forward.

Generally speaking, in an acceleration/speed contest, an engine that makes 300 hp @6000 /400 lbft @ 2500 will get beat by an engine making 400 hp @ 6000 / 300 lbft @ 2500 in equal vehicles if the cars are geared appropriately for the engine. The lower power engine may make more PEAK torque and at a lower RPM, which is good for stepping off the line and for getting a heavy load moving, but it is making much less torque at 6000 rpm than the 400 hp engine.

In a car, you aren't typically trying to get a heavy load moving from rest, so having 660 lbft @ 1600 rpm (like the Duramax) is not really necessary. Or, look at 18 wheelers, which often have ratings on the order of 400-600 hp (at maybe 1900 rpm), with 1200-1650+ lbft of torque (at 1500 rpm).

In working trucks, this is a big consideration. But in the half ton world (what Bryant would call something other than "real" trucks ), the trucks are often used primarily as cars anyway, so power numbers are becoming pretty important. It's an interesting line for them to walk.

Note how these cars with 3.5L V6s and ~300 hp / 260-270 lbft are producing LT1 (or quicker) acceleration times.

 

But as you and I both know, in the real world, engines do not all exhibit similar Tq/Hp curves, AND most of the time these same engines do NOT demonstrate the linear relationship governed by their equation P=T/dt.
In fact, Ford's old 5.0 flies all in the face of that linear relationship, belting out 300lb-ft of torque at 2100 rpm only to drop-off to about 190ft-lb at 4000 rpm, while hp is at a lowly 170 at 2100rpm and grows up to 225 at 3800 rpm.
These two curves cross each other at radical angles between the vectors, which indicates a far-from-linear relationship - yet, the 5.0 has been doing it since 1968.

Just this weekend, me in my 1991 5.0 with 225hp/300tq was able to stay with and handle Cobras with 4.6L running 320hp/317tq . Likewise, I was bowled-over by the Toyota Matrix my instructor brought to play with... he was able to stay within 4-6 car lengths of me and the Cobras on the back stretch where we reach 100-115mph, and he was right on us in the turns. I have no idea what the little engine was in that Matrix, but it was repeatedly taching over 7000rpm. We also had major competition from some MiniCoopers with turbos. I could not pull more than 2 or 3 cars away in the straights, and they were on rails in the corners. TORQUE was my salvation this weekend.

I'm not saying Hp is negligible, but Hp is FAR more important when trying to maintain high speeds or climb a long uphill grade at speed. Hp actually IS the limiting factor on top speed runs like Bonneville is known for. But for everyday driving and the occasional leapfrog jump at a traffic light, I'll take a sackfull of Tq pellets over a truckload of Hp anyday.

 

Matrix = 1.8 DOHC VVT-li 180 hp... with some TRD mods from a roll they are very decent, much like the Corolla XRS. Most people won't even take a second look at these lighter 4 cyl. cars until they cross one in a road race....

The new 180 hp turbo Mini Cooper is sick. The CooperWorks edition will probably have around 230-240 hp in a 2300 lb go cart, and yes they handle like they are on rails.

My SVT has embarrassed friends in F-bods trying to keep up in twisty roads... they are just too light and nimble. I love my Fbod, but it's no match for my SVT and much less for my Merkur in the twisties...

 

I don't even begin to doubt you. However, you're talking about about going around a road course. In a contest of acceleration or top speed, and assuming equal weight and proper gearing, the 320/317 car would (and does) absolutely destroy a 225/300 car.

Which means it made relatively low amounts of torque, and thus had to spin to a higher rpm to make good power.

As much as I try, I just can't agree with this statement (and I'm going to sound like I'm contridicting my original post). HP & Tq are interchangeable - one is a mathematical derivative of the other. They are inseperable, and one is no more important than the other.

What is important, is matching the powerband (or 'torqueband', if you prefer) and gearing of the vehicle with the intended use of said vehicle.

 

Probably tires, I'd imagine you can't jack the pressure up high enough to sustain the loads imposed by going really fast for a good amount of time. Well that is with conventional tire sizes and the typical tire fitments.

 

Torque is good. Torque at high rpm is better.

 

Most probalby, it's just tires.

But also, what truck on earth needs to go more than 80-90 mph? It's a lot of mass moving at high velocity.

Reminds me of the time when I was driving 120 km/h (about 75 mph) and a semi with a load passed me like I was standing still. My estimate is that his speed reached at least 140 km/h (90mph). I'm sure it'll get him to his destination point faster (and perhaps even save his job), but can anyone imagine such a heap of metal losing control? How much damage it could cause?

I know this sounds sort of "think of the children" mentality, or old-fashioned. But trucks should be used only for what they're designed - hauling load. At legal speed limits, or close enough.

 

Bob, I love your posts... you are a knowledgeable guy and you think before you write - always. I see it.

Thanks... Got video!
I have had so many people call BS when you tell them that a BMW 318 with a stock drivetrain was able to pass and drive away from C5s, Cobras, and Z28s. Likewise, a bone stock 1991 5.0, 5spd, 3.08:1 is able to pass and leave a 2006 Mustang GT, manual, 3.55:1 . I started taping my sessions 2 years ago. Made believers of those in the office and my car buddies who are too chicken-sh1+ to actually come to the track!
Bottom line is ANYTHING can and typically does happen at road course events. So much depends on driver's skill. But then there's the brakes, tires, conditions, type of track, weather, fuels, etc - you know the routine. Fact is - I've seen and done it. As thrilling as it might seem for me to pass a new $40k sports car in my 16 y/o Musturd, I also eat humble pie and let the guy in the MiniCooper go by me when he is faster - and that also happened this weekend.
Props go where they go.


I'm sure the little engine was lower on Tq than my 5.0 - no doubt. BUT, he did have a 6-spd. I think he has 14" rims, and I know they were low-profile performance tires. He did have Carbon-Tech pads (stock rotors). A 6-spd and smaller rims both serve to multiply (or at least maximize) the use of engine torque, and he was able go much deeper into the turn than me before braking, as he had 4-wheel discs and race pads where I had 2 disc/2 drum and street pads - he gained a lot of time right there.
So, you are right - he did keep the rpm high to use the Hp. But if latinspice-94T/A's posted numbers are correct, Chris was making @ 180hp at peak rpm in his Matrix, where I was also at about 170-180Hp when my rpms were down in the 2700-3000 range. So as we pulled out onto a back stretch, we both were putting down about the same actual Hp. It was my TORQUE that allowed me to pull away from him going down the stretch - simply holding my foot down in 4th as he went through 3rd, 4th, and even into 5th. So in this instance, we had roughly equal Hp but one car had gobs more Tq... and the Tq made the difference.

I actually rode in his car for 6 hot laps with him driving it. I couldn't see the instrumentation - it is buried deep into chrome-rimmed pods and the passenger simply can not see the gages. But I asked him what kind of RPM he was turning. He said well over 7000, close to 8. He tries to keep it over 5000 at all times on the track. Car had 40k miles on it. I am man enough to admit that I was impressed with this car.


I respectfully disagree a tiny bit - especially when dealing with engines.
You can slap a turbo on a 4-cyl and go to the moon for Hp, but you will be hurting to put Tq into it. F1 cars epitomise this... they are extremely low on Tq and often stall when dropped in the pits, they can take forever to get up to speed, but once they are finally in the powerband - they are GONE. On the opposite extreme, if your sole objective is to move a mountain, you need a crank with a longer throw which will provide you with more displacement and a mountain of Tq, but will not rev as quickly as a tiny I4. Why do people bore and stroke 460s and 455s out to 700+ cubes in top-fuel? TORQUE!!!
NASCAR is unique in that they need the best of both worlds... fast starts but high-revs and top-end speeds. They have consolidated to engines of around 358 ci which provide low rpm torque, and have pursued valvetrain technology that allows them to exceed 9000 rpm to get the Hp they need at the top end.
All 3 engine examples can easily produce 800hp, but their applications dictate their torque requirements and the architecture of the engine required to yield such figures.

IMO, torque is what causes acceleration of mass - PERIOD. (we all know F=mA, and torque is simply a force applied at a distance(length of the lever arm)).
I have been in many a stoplight encounter where the brutal torque of my well-tuned 5.0 has put me out in front of other cars with more HP, and typically I stay there until we reach speeds where I am limited by gearing and RPM and the other guy has finally reached his power zone and can benefit from it.
To me, "torque gets you moving, power pushes you on." Blending the lines of those two is some of the "art" of racing.


ABSOLUTELY!
On a 2.4-mile road course with 14 turns, many of which are more than 90*, and tangents that are often 100 - 300 yards long, accelerating from 30-40 mph up to 60mph and braking back down to 30 again is critical. All the big-engined cars have an advantage on the 4 long straights. Likewise, regardless of their power, all light cars (typically meaning 4-cylinder compacts) have an advantage in the tight sections with lots of corners. Many guys readily concede torque for weight savings in this field, but given todays turbos and blowers, you can pretty much equalize the Hp between a 4-cyl and a V8... but not the torque. The end result is a MiniCooper or Miata that is within tenths per lap of Corvettes, Cobras, and Mustangs - it gets clobbered on the stretches but gains back time in the curves.
(Just for giggles, here's a link to the track website... Carolina Motorsports Park)
And here's an "arial" of the track...


PS - I kept re-reading your first statement and I think you did actually contradict yourself a bit there.
In a top-speed run - we both agree that Hp is what it takes. Agreed... and done.
In a pure acceleration run (like a 1/4 mile drag), if all weights, gearing, reaction times, aerodynamics, etc are all equal, the ENGINE (as opposed to the car) with the most area under BOTH curves will win. It's not necessarily the one with the most Tq or Hp, but the one that has the most of both to offer because that kind of race is so time-dependent.
So in the end, I don't think we are really so far away from each others' POV.

 

How did I end up here from talking about trucks?!?!

OMG... I need caffeine!

 

lol, stay outta SE Va in the area of Richmond to Hampton, I find it kinda scary too when that much metal is flying down a highway. A few days ago I went to pick up my sister-in-law, after picking her up we were merging onto 64 and traffic was kinda heavy. Anyways, when I merge (regardless of a yield sign or not) I always check out the traffic, pick my spot and accelerate to speed where I can merge without interupting the flow of traffic then slow down to whatever the speed traffic is moving at. This night though a truck driver had a case of occularectinitus when I went for my spot in traffic, I accelerated and topped out 3rd gear and was well into the rumble strips before I could merge with traffic in the right lane, cause this guy didn't want me in front of him. Generally in my car 3rd gear is in the 90+ range when you have to shift. Seemed kinda crazy to me to be flinging that much metal around in the right lane at probably 80+ mph just keep me from merging.

 

Can only ramble on about a situation that will probably not improve itself substantially for the next 2 or 3 years.

 

Proud....no disagreement with the majority of your post. In fact, I can tell you the story of how a well-seasoned driver in an A4 V6 99 Mustang (rental) was lapping Summit Point faster than I was in my mildly modified 99 M6 T/A. Obviously my car was far more capable of his - but the "driver mod" was in full force!

Torque is work - of course it "causes" acceleration. However, 300 lb/ft of torque at 5000 rpm will accelerate a car quicker than 300 lb/ft of torque at 3000 rpm, everything else being equal. I would add that a car that makes its power down low (torque peak at lower rpm) is certainly easier to drive fast than a car that is "high strung". But in the end, the car with more HP (torque * rpm) will go quicker, everything else being equal.

HP/Tq curve....in a very real sense, this is what matters most. The car making the most average power (or torque * rpm, if that is the preference) in each gear will accelerate quickest. If you have a very 'peaky' motor, that drops well out of its powerband on a shift, then it will suffer. Similarly, if you have one that it pretty much doesn't matter where you shift it - its going to make power, then you'll go relatively fast (see "easier to drive" above).

My apparent contridiction...what I was trying to point out is that the 4.6 motor makes its power down low - evidenced by the lower rpm at which its peak torque occurs. IMO, trucks spend much more time at lower rpm, thus the benefit of more power at low rpm.

To illustrate this....lets look at the Ford 5.4 and GM 5.3 numbers I posted earlier. The 5.4 is making 365 lb/ft at 3750 rpm, and thus is making 261 HP at the same rpm. The GM 5.3 makes its peak torque of 338 at 4400 rpm, but lets assume it is also making the same torque at 3750 rpm (and by definition, it has to be making less, but it is a convenient number to use for comparison). Given this assumption then the GM 5.3 is making 241 HP at the same rpm (and actually somewhat less - would have to see the actual torqe at 3750 to be exact). The 5.4 is thus making more power at a lower rpm, making it more useable in a truck, from my perspective.

Finally...and once again....torque and HP are inseperable. HP is a much easier number to work with though. For example...tell me a car makes its peak HP at 6000 rpm, and I can give you a very good idea of where to shift it. Tell me the same car makes its peak torque at 3500 rpm, and I wouldn't have a clue.

Bob

 

For me, it's all good but this part.

I maintain that the car with 300Tq at 3000 will achieve it's max Tq delivery SOONER than the car that needs to rev to 5000. While the 5000 car is reaching that peak Tq level, the 3000 car will have already been applying max Tq and thereby applying max force to the tires and pavement, and that car will be checking out. (unless you launch the cars at their respective peak Tq revs, which will just result in tire smoke or broken parts... )

Speaking from the gut, the 3000 car will jump out front by a decent margin early, then as it winds-out (and Tq starts falling) the 5000 car will catch back up and pass ahead of it as they near top speeds (of the engines and cars) respectively.

Remember... acceleration is not linear - much like a Tq or Hp curve is not. They are typically exponential (parabolas). It will go from 0 to some BIG number very fast (within the first second), then it will slowly ramp back down to zero as the car reaches it's terminal velocity. The 3000 car will have a bigger initial number (and hence initial speed) - I guarantee that - and it will also start going back down faster too. The 5000 car will have a smaller initial number (and hence initial speed) yet it will not drop off as quickly as the other car due to the 5000rpm capability, so it will slowly wind-in the other car.

As you said before, the gearing, tire dia, aerodynamics, etc has EVERYTHING to do with which car ends up with better top-end speed, and initial 0-30, 0-60, 0-100 times etc. But if "all things were equal", I'd bet on the 3000 car to lead for the first bit, and bet on the 5000 car to have the better top end.

You know neither of us can "prove" anything when we are speculating on theoretical equalities such as this. It would be neat if we could!
Maybe we need to send this in to "MythBusters" and see what they come up with!

G-man