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600 HP, 2050 torque, occurs at all RPM's. Not true. Notice what occurs at 1500 RPM on the curve. The reason why HP continues to rise is because of >RPM. At 1800, HP starts to fall off dramatically. Notice the torque has dropped from 2050 to 1751. Can the driver feel that, absolutely. You don't feel HP, only torque.
Some folks believe higher HP doesn’t work as hard thus will get better fuel economy. That's not true, but is a good reason to buy big HP. RPM controls fuel economy and how fast you can climb a hill. HP is a calculation based on torque at a specific RPM.
HP = torque X RPM / 5252. This is the formula James Watt (Engineer) came up with this marketing gimmick when he was trying to sell his steam engine to replace horses in 1770s. We use this formula today. He determined, a horse could lift 33,000 lbs 1 foot in 1 minute, or 550 lbs 1 foot in 1 second. The constant 5252 = 33,000 divided by 2 X 3.1416 (Pi). 6.2832 is the circumference of a 1’ radius pulley. So, higher RPM’s increases HP.
Let’s say it takes 350 HP to pull a loaded trailer at 65 MPH on level ground. Does it matter the engine HP rating? No, as long as it's at lease 350 HP. Do you see a pattern? RPM is key to engine performance with like torque.
Today's engines are amazing and generate max torque in the 900-1,000 RPM range. This is why gear ratio's continue to drop (smaller #) so you can take advantage of what the engineers have designed. It wasn't that long ago that we were in the low 3's, now we're in the mid to high 2's. Just because your pulling grades doesn't mean you need a larger drive gear. That's what the transmission is for.
Grandpa was in the low 4's, Dad was in the 3's, Jr is now in the 2's. It's all tied to engine RPM and identifying the sweet spot for best performance. Pull the torque curves on the engines your considering and find that sales professional that can help explain this technology for best performance.
Could you purchase 600 HP and get close to the same fuel economy while matching the performance of a 455 HP? Theoretically YES (disregard the torque difference), but the monster would have to be driven like a 455. It still takes 350 HP to pull a trailer on level ground. 600 could climb the hill much faster, but would drink more fuel if you utilize what it was designed to do with high torque and HP.
[email protected] 816-500-3225. Reach out if we can help. Education is key to success.
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5moThis is terrific. Congratulations.