Hybrid Cars - Towing Weight - Batteries

Jan 20, 2022
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Can someone explain why the Gov.uk https://www.gov.uk/vehicle-weights-explained states that the Car Weight on a hybrid does not include the weight of the batteries? We have just bought a Peugeot 3008 300bhp which has a Kerb Weight of 1840kg. Using 85% one gets 1564kg. Yet the Maximum Tow Weight is listed as 1250kg which implies a kerb weight of 1470.

We are going to have to change our caravan to a smaller one (this was planned but ...) . I would just like to understand "Why". I have not been able to find this explained anywhere.
 
Nov 6, 2005
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Yet the Maximum Tow Weight is listed as 1250kg which implies a kerb weight of 1470.
That's invalid logic - the maximum towing weight is determined by a whole stack of engineering criteria and has no direct relationship to the kerb weight.

You'll need a caravan under 1250 kg MTPLM with that towcar.
 
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Jul 18, 2017
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Seems very strange excluding the weight of batteries from the MIRO of an EV as it does not make sense. However it may give an insurance company a good excuse to void a policy in the event of a claim.
 
Nov 11, 2009
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That seems odd as the battery is an integral part of the car, just like it’s engine and gearbox. But notwithstanding you are limited by the manufacture maximum towing weight limit.
 
Nov 6, 2005
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I don't think it's anything to do with the battery weight - I think the OP has misunderstood how Max Towing Weight is arrived at.

Unladen weight isn't the same as kerb weight - batteries are probably excluded from unladen weight for the same reason that full tank contents are.
 
Jul 18, 2017
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Unladen weight

The unladen weight of any vehicle is the weight of the vehicle when it’s not carrying any passengers, goods or other items.

It includes the body and all parts normally used with the vehicle or trailer when it’s used on a road.

It doesn’t include the weight of:
  • fuel
  • batteries in an electric vehicle - unless it’s a mobility scooter or powered wheelchair
Above clearly states when it is being used on a road however how can it be used on the road if it does not have fuel?

I think the wording is very misleading however going by the above it does not apply to hybrid vehicles only EVs.
 
Mar 14, 2005
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Can someone explain why the Gov.uk https://www.gov.uk/vehicle-weights-explained states that the Car Weight on a hybrid does not include the weight of the batteries?
Hmm... That certainly looks wrong! and it wouldn't be the first time the Govt Web site has given wrong information. I'm not claiming its a conspiracy, it sadly one of the problems of trying to condense several thousands words which have fairly specific meaning as found in acts of parliament or regulations into a few tens words. Sometimes the detail is seriously lost in translation.

We have just bought a Peugeot 3008 300bhp which has a Kerb Weight of 1840kg. Using 85% one gets 1564kg. Yet the Maximum Tow Weight is listed as 1250kg which implies a kerb weight of 1470.
You are juggling with two unrelated matters here. The 85% figure is just advice from the caravan industry. It has no authority in law, but it does represent the industry trying to give guidance to people who to purchase a caravan or car for towing. However

The cars legal specifications must always take precedence over any advice regardless of how well meaning it is.

As I think Roger has pointed out a given towed weight limit cannot be used to work out a kerbweight or indeed a Maximum Authorised Mass.

We are going to have to change our caravan to a smaller one (this was planned but ...) . I would just like to understand "Why". I have not been able to find this explained anywhere.
Well I hope this has at least partly explained it, but essentially you are not comparing like for like criteria, and there is not simple direct calculation that links them together.
 
Jul 23, 2021
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Hmm... That certainly looks wrong! and it wouldn't be the first time the Govt Web site has given wrong information. I'm not claiming its a conspiracy, it sadly one of the problems of trying to condense several thousands words which have fairly specific meaning as found in acts of parliament or regulations into a few tens words. Sometimes the detail is seriously lost in translation.
My suspicion is it is a hangover from when some EVs had removable batteries (the classic lead-acid based milk float) and the battery weight was considered part of the payload.

Completely irrelevant for a modern EV, Hybrid or PHEV. All that legaly matters is the weights stamped on the weight plate of the car, the actual weight of the trailer (less nose weight) and the actual standalone weight of the trailer relating to its own MTPLM.
 
Nov 6, 2005
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It should be noted that unladen weight, as opposed to kerb weight or mass in service is used in very little legislation relating to cars - it's more to do with commercial vehicles.
 
Mar 14, 2005
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lutzschelisch.wix.com
It should be noted that unladen weight, as opposed to kerb weight or mass in service is used in very little legislation relating to cars - it's more to do with commercial vehicles.
Yes indeed. Unladen weight is irrelevant for cars. Besides, neither unladen weight nor kerbweight are documented anywhere. Only mass in running order (also known as mass in service) and actual mass are documented. Actual mass is not shown on a V5c though. All four weight terms are defined differently.
All that legaly matters is the weights stamped on the weight plate of the car, the actual weight of the trailer (less nose weight) and the actual standalone weight of the trailer relating to its own MTPLM.
Just to clarify, "the actual weight of the trailer (less nose weight)" is the axle load. The weight plate on the trailer must also display the maximum permissible noseweight. On the plate it is referred to as "axle 0".
 
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May 7, 2012
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If the battery weight is not included in the unladen weight I would think it should be included if using the 85% recommendation as it is fixed and the car will weight this unladen. I suppose the law makers think that it could be used with the batteries removed using just the ICE engine so discount the batteries or possibly if they are replaced technology will mean the newer ones are lighter.
As the others have said the makers towing limit is not based on the vehicle weight, but the ability of the car to move the load. In general it is the ability of the car to restart five times on a 12% slope. Most cars do have a towing limit well above their kerb weight, but only a fool would try to tow a caravan at some of the towing weights published. With a hybrid the manufacturer would have to use the ICE engine only, simply, because the electric element might be used up and have no input, meaning the towing limit will look low in many cases.
 
Oct 8, 2006
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If the battery weight is not included in the unladen weight I would think it should be included if using the 85% recommendation as it is fixed and the car will weight this unladen. I suppose the law makers think that it could be used with the batteries removed using just the ICE engine so discount the batteries or possibly if they are replaced technology will mean the newer ones are lighter.
[snip]

A bit difficult given that most EV/hybrid batteries are part of the car construction, i.e. the floor pan!
 
Jul 23, 2021
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Maybe a hybrid is not classed as an EV?
The original article only referenced "electric vehicles". Its clearly out of date for the context of any modern EV (hybrid, PHEV, BEV) where typically the battery pack is removable in the same way as the fuel tank is removable in an ICE. Can it be done? yes. Is it an every day occurrence? No. (Unless your car is made by Neo).
 
Jun 16, 2020
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The original article only referenced "electric vehicles". Its clearly out of date for the context of any modern EV (hybrid, PHEV, BEV) where typically the battery pack is removable in the same way as the fuel tank is removable in an ICE. Can it be done? yes. Is it an every day occurrence? No. (Unless your car is made by Neo).
I watched that fifth gear last night. That Nio make so much sense. I once got shouted down for suggesting replaceable batteries as the way to go. In fact, they would have been ideal in a black cab. An opportunity missed there.


And this, look at 4’45”
View: https://youtu.be/3HQgAxUDYB0




John
 
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Mar 14, 2005
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Many of the newest EV's have a battery pack that is structural to the car, but the cells in the pack probably can be changed.
 
Jul 18, 2017
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It's irrelevant whether a hybrid vehicle is classed as an electric vehicle or not because unladen weight itself has no significance for a private car.
The reference was to the wording on the gov.uk website.
 
Nov 6, 2005
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The reference was to the wording on the gov.uk website.
It's correct on the gov.uk website, the weight of a commercial EV's battery isn't included in the unladen weight - but unladen weight isn't used for cars in legislation.
 
Jul 18, 2017
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It's correct on the gov.uk website, the weight of a commercial EV's battery isn't included in the unladen weight - but unladen weight isn't used for cars in legislation.
Not disputing, but the gov.uk site does not seem to make any reference whether it applies for a commercial or non commercial vehicle.
 
Mar 14, 2005
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Not disputing, but the gov.uk site does not seem to make any reference whether it applies for a commercial or non commercial vehicle.
Correct, but the 85% recommendation is quite clearly based on kerbweight, not unladen weight and there is no legislation relating to cars where unladen weight is an issue, so any gov.uk reference to unladen weight is irrelevant to us.
 
Jul 18, 2017
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Correct, but the 85% recommendation is quite clearly based on kerbweight, not unladen weight and there is no legislation relating to cars where unladen weight is an issue, so any gov.uk reference to unladen weight is irrelevant to us.
As pointed out the term "kerb weight" does not exist in legislation. Makes you wonder how an insurance company can have a clause stating that insurance is void if you exceed 95% of the kerb weight of the towing vehicle? Surely that would be an Unfair Clause in the event of a claim as the kerbweight could vary quite a bit for the same model of towing vehicle?
 
Nov 11, 2009
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As pointed out the term "kerb weight" does not exist in legislation. Makes you wonder how an insurance company can have a clause stating that insurance is void if you exceed 95% of the kerb weight of the towing vehicle? Surely that would be an Unfair Clause in the event of a claim as the kerbweight could vary quite a bit for the same model of towing vehicle?
I think this has been raised before. But I know the insurer is talking a load of old baloney, but even if towing vehicle kerbweight were to vary between similar vehicles because of specification difference, 95% of whatever the kerbweight was would still be the insurers maximum allowed tow weight. But it’s a non sequitur.
 

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