Just speaking of towing capability and not offroading ability, engine size and vehicle weight have everything to do with towing. A little Tacoma can never pull what a full size does... not enough engine and not enough vehicle weight. Also, the key to a good pulling engine is at what RPM peak torque is made and for how long it is maintained. Good example... 2 stroke motorcycles (ie. CR 250) make a ton of torque... but they don't do it until an outrageous RPM ... like 7000. 4 strokes... and the Polaris twin make a ton of torque at a low RPM and keep that torque curve pretty flat for the majority of the power band - hence why they pull and work so darn well. There is a great article about the differences between hp and torque in this months Hot Rod magazine. Basically torque is the ability to twist (to do work) and horsepower is how fast it can do that same amount of work (fast as measured in RPMs).

 

I've always heard it this way. Torque gets you moving and horse power keeps you moving.
And that 9500 lb tow capacity? Sounds like the tail will be wagging the dog. How much does that truck weigh. If it isn't around 7000lbs I'd be concerned when cornering and stopping. I'll take american muscle any day. I prefer GM but all the american big three are great products. I see more and more jobs going out of the USA to Mexico and overseas. I feel for all the younger generation.I hope they all can find jobs so I can collect my social security when I retire. IF I can retire. What were we talking about anyway!

Steve

 

Keep in mind, HP cannot actually be measured. It is a figure that is based on the torque of a motor and figured at 5250rpms if memory serves me correct. That is why you can have motors with high torque on one end of the scale and low hp and vice versa. If a motor has high HP, then it will have a high torque value somewhere on the rpm scale. They run hand and hand most of the time with exception of very low rpm motors such as diesels.

 

Actually, horsepower is a function of torque and engine speed. HP is equal to Torque/Time. The number 5250 is a conversion factor, which is obtained b/c you must convert rpm to rad/s and revolutions to radians in order to calculate HP. So, 1 revolution equals 2pi radians, and 1rpm is 60 rev/second. This results in ft*lb/s. To convert ft*lb/s to HP, you must multiply by 550. So, putting it all together you get 555*60/2pi which equals 5252. So, to calculate HP at a given engine speed, you just multiply the torque by the rpm and divide by 5252. Diesels, for example, don't make much HP because all the torque is produced at low rpm. Jap engines, on the other hand, can make lots of HP at relatively low torque values because they spin so fast. Take a diesel engine that makes 500 ft*lb torque at 2500 rpm: thats works out to 238 hp. On the other hand, take the S2000 which makes about 200 ft*lb at 7000 rpm. This works out to 266 hp. So now you know.

 

And now you know.......... the rest of the story.[img]i/expressions/face-icon-small-happy.gif[/img]

 

The most popular engine for Torque when upgrading the old L Head or F-Head on the ****** Jeep....is the Buick V-6 Odd-Fire. Alone it has a lot of low end torque, but you can put a Tractor cam in it....I have peak torque on mine under 2000 RPMS. Put the heavy flywheel on (mine weighs 50-60lbs), and you have engine that refuses to die.

The Odd-fire motor has the name, because GM rushed it out the door in the mid-60's. They took their V-8 and literally, just chopped off 2 cylinders. All the other parts were from the V-8, including the distributor. So when you look at the Distributor, there is a missing 7 and 8 sparkplug. So when the engine runs, it skips 7 and 8 in the firing sequence. The Even-fire V-6 doesn't do that.

They made the V-6 225 until like 67 or 68. But it was so popular, they brought back in the 73 or 74, as the 236 (smog was added, so they pumped it up a few HP to compensate).

Totally off-topic....but I still find it interesting.

Yes...Torque is very important, especially for OHV stuff.

 

Nissan Titan -- 379lbs-ft of TQ... As much as any FORD that is gas powered... Your point???

 

Yep -- you were wrong....

 

2manytoys, you are right that the Nissan Titan can pull 9500lbs, but the new F-150 can pull a whopping 9900lbs. The Titan does make more peak torque 379 to 365 for the F-150 but the F-150 makes more low-end torque. The F-150 makes 80% of its peak torque at only 1000rpms while the Titan makes 90% at 2600rpms. There is no doubt that the Titan is a good truck but I'll take the F-150 over it anyday. Sorry to say gnd111, but your wrong to, Fords 6.8liter V10 engine makes 425lbs-ft. of torque.

 

yo gnd111 those were some great constructive posts thanks for your input.
man my feelings are so hurt i dont know if i can go on...

Elbongo thanks for handling that one for me[img]i/expressions/face-icon-small-wink.gif[/img]

Rh68 that was a great post...thanks for the info..