wnjj wrote:
brulaz wrote:
And Peak Torque and HP numbers are good info. But what I really want is the actual torque vs rpm curve. And even there, with all the sophisticated torque management built into today's engines, that doesn't tell the whole story.
Exactly. People get too hung up on peak rated HP/torque which cannot be applied all of the time.
In addition to the HP/torque curves across RPM you need vehicle road speed across RPM in all available gears. If you cannot put the peak power to the wheels in the gear you are in for a particular grade and road speed your engine is being under-utilized.
On that note: The more gears you have available, the less having a "peaky" engine matters since you will be able to more effectively keep the engine near its peak.
One more point that needs to be (re)stated with regard to torque "moving the load":
Rear axle torque is what moves the load which is dependent upon, but no where near the engine's torque output.
The truth of the matter is that, more often than not, people don't really understand what they're talking about when it comes to torque, HP and gearing so the less choices they have the better off they might be. For instance if you buy a Duramax the GM engineers have decided that offering different axle ratios confuses the issue, just get in the truck and drive it. Ford has decided for those who need an F250 or 350 SRW they would offer a choice of 2 different axle ratios; if you really need to pull heavy then get an F350 dually and it will have a 3.73 ratio. For those who are pulling heavier than all but the very heaviest of RV's you can buy an F450 and it will have a 4.30 ratio. I can't help but cringe every time I see a Ford F450 hooked up to a little 16,000 lb RV. Ram gives the consumer too many axle choices and my bet is that 7 times out of 10 the consumer makes the wrong choice. All the manufacturers are offering both 3/4 tons and 1 ton SRW. They should quit making the 2500 series trucks and then classify the current 1 ton SRW as a 2500 / F250.
