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Discussion Starter #1
I have a Mini Countryman Hybrid. In electric mode I have found that power is always fed in very gradually.
From a standing start the car accelerates slowly then gets to about 20mph before giving it's full power.
Even at cruising, power is fed in gradually.

This is true in all driving modes.
It seems over cautious for a 1700kg car with an 88hp motor!

Is this the case with other hybrids such as the Golf GTE?
 

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Kona PremSe64k 2020+bluelink +ohme
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The Kona has been criticised for having too much power early on, causing wheelspin. Most people blame this on a mix of the default Nexen tyres and the front-wheel drive. Though in part it can be controlled, as well as by the pedal, by reducing driving mode from sport down to eco. We use Sport mode to ensure a quick get away at junctions where you want to get away sharpish.
 

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The Kona has been criticised for having too much power early on, causing wheelspin. Most people blame this on a mix of the default Nexen tyres and the front-wheel drive. Though in part it can be controlled, as well as by the pedal, by reducing driving mode from sport down to eco. We use Sport mode to ensure a quick get away at junctions where you want to get away sharpish.
Yeah, our Ioniq (88kW motor) spins the wheels even in eco mode on a dry grippy road. It's probably quite a useful safety feature to not allow maximum torque from a standing start - these are consumer vehicles, not race cars, after all.
 

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I get similar in the Passat GTE, though from standing start it electric only,then the engine starts around 20mph then I get full power. I think it's just the time taken to get the engine started and engaged in the drive. Does the Mini let the engine run while stationary, the GTE turns it off.
 

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Discussion Starter #6
I get similar in the Passat GTE, though from standing start it electric only,then the engine starts around 20mph then I get full power. I think it's just the time taken to get the engine started and engaged in the drive. Does the Mini let the engine run while stationary, the GTE turns it off.
The Mini can keep engine on if the gearbox is in the sport position, otherwise it's off for the initial pull away then comes on between 5 and 10mph.

However, here I am talking only about the electric motor.
 

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Discussion Starter #7
Yeah, our Ioniq (88kW motor) spins the wheels even in eco mode on a dry grippy road. It's probably quite a useful safety feature to not allow maximum torque from a standing start - these are consumer vehicles, not race cars, after all.
I agree that I certainly do not want wheelspin but as the system doesn't take into account steering position or available grip it's default seems to be far too cautious for straight dry roads, when leaving a junction for example. A driver can take conditions into account and apply throttle accordingly.

Anyway, I shouldn't really complain as the car remains pretty rapid off the line while being nice and efficient.

Thanks all for your input.

It seems it is common practice.
 

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Kia Soul EV 2020
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You should not be mixing full EVs with hybrids. Because in the case of the GTE, the clutch between the e-motor and the wheels has torque limitations that need to be considered. BEV's don't have clutches, so have no torque limitations either (unless the manufacturer gives them some).
 

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Discussion Starter #9
You should not be mixing full EVs with hybrids. Because in the case of the GTE, the clutch between the e-motor and the wheels has torque limitations that need to be considered. BEV's don't have clutches, so have no torque limitations either (unless the manufacturer gives them some).
The Mini Countryman and BMW 225xe have a motor directly powering the rear wheels rather than going to the front wheels via the gearbox.
 

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BEV's don't have clutches, so have no torque limitations either (unless the manufacturer gives them some)
Strictly, on a BEV there will be a torque limitation set by the maximum allowable motor current.
 

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Discussion Starter #14
Unless people have studied physics/ engineering they mostly don't really understand either of these terms
I don't think so, the relationship between torque and power is not complicated.

The motor used in the Mini countryman has flat torque of 165nm at 0-3000rpm.
Initially I did consider that the feeling of gradual power on was because at low rpms the motor is incapable of generating it's full power. However, this pattern of gradual power on occurs even at 30mph when accelerating. The powerguage takes a few seconds to climb.
This points to it not being an rpm based torque limiter.

All I can think is that it's a very simple system to ensure there is no wheelspin.
If this is the case it's a very simple traction control system that does not take into account steering forces or car speed, 88hp will not make the rear wheels spin at 30mph!

It's a little surprising that in a car with a traction control system, they would use such a simple torque map rather than allowing traction control to..... control the traction.

Ah well, rambling now.....
 

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I don't think so, the relationship between torque and power is not complicated.

The motor used in the Mini countryman has flat torque of 165nm at 0-3000rpm.
Initially I did consider that the feeling of gradual power on was because at low rpms the motor is incapable of generating it's full power. However, this pattern of gradual power on occurs even at 30mph when accelerating. The powerguage takes a few seconds to climb.
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I think you're not quite following what torque actually means - this directly influences acceleration . Even with loads of torque, and consequently instant acceleration/ wheel spin, the actual power at low rotational speed will be low because power is the product of torque and speed. So your flat torque characteristic will be accompanied by a progressively increasing power value proportional to the rotational speed.
 

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So your flat torque characteristic will be accompanied by a progressively increasing power value proportional to the rotational speed.
...and progressively increasing battery current until the battery current limit setting is reached, then you get decreasing torque with increasing speed at constant electrical power.

peak torque but not peak power would typically be available when accelerating from a standstill with a BEV.
 

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Discussion Starter #17
I think you're not quite following what torque actually means - this directly influences acceleration . Even with loads of torque, and consequently instant acceleration/ wheel spin, the actual power at low rotational speed will be low because power is the product of torque and speed. So your flat torque characteristic will be accompanied by a progressively increasing power value proportional to the rotational speed.
Why would you believe that?

I did state that the fact that flat torque curves yield a progressive increase in power when I said:

"I did consider that the feeling of gradual power on was because at low rpms the motor is incapable of generating it's full power. "

Perhaps I could have been clearer and stated that at, for example 1500rpm (about 8mph in this case) , 165nm of torque would yield just 25kw.

I also stated why I believe this is not the only issue when I said:
" However, this pattern of gradual power on occurs even at 30mph when accelerating. "

From 16mph the motor generates 51kw then from about 21mph the motor generates 65kw which is maintained flat until cut off at 78mph

This would be the obvious answer if it only happened at low speeds. Which is why I discounted it in my previous post.
 

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From 16mph the motor generates 51kw then from about 21mph the motor generates 65kw which is maintained flat until cut off at 78mph
65kW from the battery would exceed the motor’s current and torque limit at low speeds, but not higher speeds. at higher speeds, the same power from the battery produces less torque, which keeps you under the limit. with enough (multiple) motors, you can dump 65kW from the battery into the motors from standstill, without exceeding the torque limit of the individual motors, producing increased acceleration assuming you have sufficient traction.
 

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Its very likely just throttle mapping.

If you floor it at 30mph and it still takes a few seconds to hit peak power, its clearly ECU controlled rather than torque/rpm/power related.

I suspect the issue is that the e-motor is in the rear, and hitting the rear drivetrain with a big wodge of torque isnt great for your typical driver. They'll end up in a hedge. Especially relevant in a hybrid car like the Mini, where the engines driving the front wheels, and the characteristics will be very different in electric only mode, than it will in hybrid mode.
 
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