# Kwh required to replace existing Diesel engine in SUV

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Guiness-4-U
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Joined: 04/02/2011
Points: 6

Can anyone help me with this calculation?
I have a KIA Sorento 2010 model, it is a great car 4WD SVU.
It has the following:-
1. Weight 1884 Kg Dry (fuel tank 70 ltrs)
2. Six Speed Auto Trans
3. 2.2 litre intercooled turbo Diesel, Output 145Kw at 3800 rpm, 436Nm @ 1800-2500 RPM
City driving towing a trailer with a golf cart about half the time and with air conditioner on occasions, It consumes 11.5 litres of diesel per 100 klm.
The question is, Diesel motor is more efficient than a petrol motor, and an Electric motor is more efficient than a Diesel motor.
So What is the calculation to find out under my driving conditions(11.5 ltr per 100 klm), if I convert to electric, how many Kwh of electricity would I use per 100 klm.
i.e.( 11 Litres of diesel for a the above diesel motor) (How many Kwh for an electric motor Substitute)
Thanks
Guiness-4-U

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Sergei
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Joined: 08/18/2011
Points: 19
Re: Kwh required to replace existing Diesel engine in SUV

The torque says something about the acceleration at low motor speeds.
But as soon when the motor is running at higher speeds,the power , the 145kW kicks in.
So, if you look at these two on a schematic, torque curve is in front of power output curve, not total in front, they overlap for a certain range.
Electric motors works a bit different. They go to full power at start and, they have a higher efficiency compared to the diesel.

So a way could be: divide 145*0,45 = around 65,25kW
Yes, the effeciency of a diesel is higher then a gasoline engine , but still under 50%

A electric motors are more a problem: their effeciency may be between 78 to 93% so your first concern is to choose a motor with higher effeciency. Lucjy for you, effeciency and max power are related.

Let's assume 90% : 65.25/0,9 = 72,5kW
So, you sure need 72,5kW electrical compared to the 145kW diesel.

Batteries : the most important factor is the power (Ah) that a battery can give to a motor.
And not forget, controllers stop if the voltage drops below a certain limit.

Starters : motor voltage = battery voltage must fit.
W/V gives the Ah

But there is not soo much to say cause there are various battery models with their own discharge capacity and maximum discharge capacity
Note: the motor controller has also no 100% effeciency so there is some extra loss between battery and motor. Even the used cabling leads to power loss.

Sergei
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Joined: 08/18/2011
Points: 19
Re: Kwh required to replace existing Diesel engine in SUV

Is included in the power loss percentage of the motor.
Thers is indeed some power loss when burning diesel but it's the engine that looses most power.
And the turbo: works only good at higher engine speeds, the turbo is included in the overall effeciency.
Side note: eff. rates for a direct injection are a bit higher, approx. 60 to 63%
Side note 2: if you use wheel motors then you gain some power.

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