d.h

Does anyone know what is the difference between peek horsepower and total horsepower? I saw this term in some hybrid cars.

We all know what peek horsepower is. I'm guessing that total horsepower is the power combine by the engine and the battery. So do they have a different peek horsepower in these hybrid cars?

sahtt

Judging from how your questions is set up, I'll leave the technical mumbo jumbo out of it.

Peak* horsepower is the maximum amount of power a drivetrain can produce. Total horsepower is usually taken as the amount of power produced from idle through redline, or area under the "curve" of the dyno.

For instance, the Lexus V8 engine from 98 and on [until ls460] had 290 peak horsepower but more importantly had most of that power throughout the RPM range. The power closer to idle is what commonly is refered to as "torque down low". The car has no problems accelerating at 2k RPMS. On the other hand, the s2000 has about the same power as a civic until near the vtech crossover, and hammering it at 2k rpms will not get you anywhere until next tuesday.

What the media is probably trying to get across to you is that although a prius and a standard corola have the same peak horsepower, the hybrid is much easier to drive and has near its peak horsepower throughout the rev range from idle to redline.

Depending on the setup, some hybrids only use the engine or only use the electric motors depending on the throttle application. Some, like the LS460h, use both the engine and the electric motors at the same time to produce peak power. More economical applications may only use the gas engine during WOT on the highway for example.

It is an interesting process trying to determine the exact output of hybrid cars that can produce power from two independent sources.

rockville

Actually, I think they are just trying to be clear about the correct way to state the power of a hybrid car. The electric motor produces say 40hp and the gas one produces say 100hp. However the car can't put 140hp down to the wheels (even ignoring all those peaky drive train losses). The issue is that the electric motor's peak power may not line up with the peak power of the gas motor. If the electric peaks at say 3000RPM and the gas peaks at 5600RPM then the total HP the car can actually deliver to the drive train at any one time is something less than 140hp. This would be easier to explain with some power charts.

d.h

^ That's the understanding that I have. The peak power is probably less than the total power. Basically, the peak power is what the engine can max out at.

Example

Lexus RX330 - 230hp
Lexus RX400 - 268hp

So, I'm guessing the peak horsepower is the same or close to RX330 since they both have the 3.3L