Horsepower is horsepower?
If that theory is true (in real circumstances), then a 385hp 6.7L Cummins diesel shouldn't spank a 381hp Toyota Tundra when both are tested 0-60 towing a 5740# boat. But it did. Must be the adva...
Forum Discussion
Hannibal wrote:
6500rpm? Good grief! What are you towing with? I'm perfectly fine with 3800-4200~rpm for the grades but 6500 is well above my listening comfort zone. 6500rpm is 65mph in 2nd gear? My '05 Hemi Ram with auto/3.73 ran 4400~rpm in 2nd at 65mph. Pulled like a diesel. Sounded like an animal!
The Hemi has a taller 2nd gear, a result of having a narrower ratio spread,(I assume you have the 545RFE trans?) and is out of it's powerband at 6500, and likely cannot rev that high anyhow. If you re-read my post, what I was alluding to, was that my truck is caught between gears at that speed, when at 8000', up a 6-7% grade, if I desire to go 60mph plus. I always have the option to slow down, right? You have a similar situation, in that you MUST run 2nd gear under certain circumstances, as 3rd would be WAY to all.
And yes, 6500 rpm is a bit ridiculous. Last year, leaving (IIRC) Salt Lake city, I think on I5 (i'm from Canada, I can't recall if this is correct location I'm citing). We were full GCWR, and I had the option of the slow lane with the semis, going 30 mph, or the middle lane going 60 mph. I REFUSE to be the dolt that is not in the slow lane, holding everyone up, for no reason. So, i hit resume on the cruise, and the truck held second gear. It was a bit noisy, didn't sound particularly good, but the temp gauges all stayed at half or below.
As it relates to this discussion, my truck gas 302 hp, but only 280 ft/lbs of torque. So it is the anti-thesis of a diesel. It can do the job, it just needs to rev. Looking at it another way, 6500 rpm is below the cruising rpm on my ATV, Snowmobile, and my last 2 motorcycles. I'm not saying it's ideal, far from it, but it is manageable, for the hour or so per year I'm in that situation.
Some numbers for the F150 gas engines.
ENGINE 3.7
RPM TORQUE HORSEPOWER
2000 240 91
2500 265 126
3000 255 146
3500 265 177
4000 280 213
4500 275 236
5000 270 257
5500 260 272
6000 250 286
6500 245 303
ENGINE 5.0
RPM TORQUE HORSEPOWER
2000 270 103
2500 280 133
3000 320 183
3500 340 227
4000 370 282
4500 380 326
5000 360 343
5500 345 361
6000 315 360
6500 0
ENGINE ECO
RPM TORQUE HORSEPOWER
2000 365 139
2500 420 200
3000 420 240
3500 405 270
4000 390 297
4500 375 321
5000 370 352
5500 335 351
6000 280 320
