RX450h has 477 combined hp why isn't it faster 0-60?
03-13-17, 05:35 PM
#1
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RX450h has 477 combined hp why isn't it faster 0-60?
By the technical spec, the combined total hp is 477 hp (245hp from the 3.5 liter gas engine, 165 hp from the front electric motor and 67 hp from the rear electric motor for AWD), with a curb weight of 4,652 lbs (AWD) the hp/weight ratio is a favorable 9.75 lb/hp. In comparison. the IS-F with the big 5.0 liter V8 and 416 hp and 3780 lb has a 9.09 lb/hp ration.
So if under full acceleration you get the combined power of the gas engine + front + rear electric motors, RX450h should go form 0-60 in 5.5 seconds or less.
Is it because the CVT?
So if under full acceleration you get the combined power of the gas engine + front + rear electric motors, RX450h should go form 0-60 in 5.5 seconds or less.
Is it because the CVT?
03-13-17, 06:43 PM
#2
Lead Lap
Because you don't add them all up.
The powersplit transmission splits the ICE somewhere between 2/3 and 3/4 (I can't remember exactly) between the MG1 and MG2 - which means that approximately Up to 2/3 (Or is it 1/3?) of ICE's 245 HP gets converted into electricity and that electricity is used to power the motor - along with whatever is available from the battery - up to an electronically-managed 295 HP.
You can never get enough power out of the battery alone to max power (220 HP) the front and rear motors - and the ICE is needed to generate power to send to the motors.
There's enough power available from the battery to assist the ICE to where there's 295 HP available in total (electronically managed/limited) up until the battery has depleted and the ICE's 245 HP alone is all that's available (since you can never get more than 245 HP out of the system once the battery has been depleted - and you'd only know that if/when you were continuously calling for max engine power - meaning that the driver wasn't calling for something less than the 245 HP that the ICE's capable of putting out so that the excess could be added back into the battery).
There are some technical inaccuracies and omissions with my explanation - but I think it's close enough for an overview,
The powersplit transmission splits the ICE somewhere between 2/3 and 3/4 (I can't remember exactly) between the MG1 and MG2 - which means that approximately Up to 2/3 (Or is it 1/3?) of ICE's 245 HP gets converted into electricity and that electricity is used to power the motor - along with whatever is available from the battery - up to an electronically-managed 295 HP.
You can never get enough power out of the battery alone to max power (220 HP) the front and rear motors - and the ICE is needed to generate power to send to the motors.
There's enough power available from the battery to assist the ICE to where there's 295 HP available in total (electronically managed/limited) up until the battery has depleted and the ICE's 245 HP alone is all that's available (since you can never get more than 245 HP out of the system once the battery has been depleted - and you'd only know that if/when you were continuously calling for max engine power - meaning that the driver wasn't calling for something less than the 245 HP that the ICE's capable of putting out so that the excess could be added back into the battery).
There are some technical inaccuracies and omissions with my explanation - but I think it's close enough for an overview,
Last edited by NateJG; 03-13-17 at 07:05 PM.
03-15-17, 11:36 AM
#6
It would then weigh a bit more than 4600 lbs however...
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03-15-17, 07:43 PM
#8
Lead Lap
I've been wondering why I haven't seen someone reprogram one for dragstrip duty (or at least repurpose the drivetrain into a lighter frame).
And I started a thread months ago regarding dyno torque and horsepower to no avail.
And I started a thread months ago regarding dyno torque and horsepower to no avail.
03-17-17, 02:31 PM
#10
The more I learn about LiIon batteries limitations and contraindications, the more I appreciate the wise Lexus decision to stay with the NiMh ones; with the last incarnation of the Toyota Prius they pushed a lot beyond the use of the improved NiMh battery. The real limit of the RX450h, resides in the excessive weight. Lexus should learn from the European industry, every generation of Mercedes, Bmw, Land Rover SUV weight hundred of pounds less that the previous one, thanks to the increased use of alloy and high resistance steel. Heck, even my Prius has the bonnet built in alloy... it is time to wake up, Lexus!
03-17-17, 04:09 PM
#11
Lead Lap
The more I learn about LiPo batteries, the more I like LiFe chemistry.
While my Drone-operating friends love LiPo, my Ham Radio friends love LiFe - and they (LiFe's) accept very rapid charges; and don't share the spontaneous combustion tendency attributed to LiPo's.
73
NateJG
While my Drone-operating friends love LiPo, my Ham Radio friends love LiFe - and they (LiFe's) accept very rapid charges; and don't share the spontaneous combustion tendency attributed to LiPo's.
73
NateJG
03-18-17, 08:16 AM
#12
Instructor
I understand Toyota made the decision to stick with Nikel Hydride due to resource issues. Remember that lithium battery needs certain rare earth metals which only come from a number of different places including many mines owned by state owned corporation of communist China.
I think you know what kind of relationship exists between the two nations. Toyota wasn't about to be at the mercy of .......... I think you know the story.........
I think you know what kind of relationship exists between the two nations. Toyota wasn't about to be at the mercy of .......... I think you know the story.........
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