US Curb and EU Kerb weights, an attempt at clarifying the differences.

[Boss330]

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I have been asked (by swamp2) to do a write up on the different standards for curb weights. There are a lot of discussions related to the weight of cars and how to compare EU and US weights (Apart from lbs to kg I mean ).

As this is a work in progress, it might not have all relevant info at the moment, there might be inaccuracies or contradictions. I welcome any constructive input to make this info as accurate, reliable and useful as possible

Summary:

Weight standards currently used by BMW and other German/European brands on their official web sites.

EU/Germany:
1. Leergewicht EU ( Car with 90% fuel, 68kg driver, 7kg luggage (75kg). Latest EU definition uses only driver @ 75kg )
2. Leergewicht DIN ( Car with 90% fuel, no driver, no luggage )

USA:
1. Curb weight ( Inconsistent reporting, with or without driver, unknown and inconsistent equipment level ).

Recommendation:
Use the European standards for apples to apples comparison. For cars that lack European weights, further research is needed to determine what is included in that cars stated US "Curb weight".



Summary of definitions:

US Curb Weight:

• Weight of car with fluids and fuel at 100% as well as weight of any option expected to be in more than 33% of vehicles sold. Driver not included in US legal defintion, but usually included in manufacturers public figures.

EU Kerb Weight/Leergewicht EG:


Latest EU definition of "mass in running order" (curb weight) according to 1230/2012/EEC:

• "the mass of the vehicle, with its fuel tank(s) filled to at least 90 % of its or their capacity/ies, including the mass of the driver, of the fuel and liquids, fitted with the standard equipment in accordance with the manufacturer’s specifications and, when they are fitted, the mass of the bodywork, the cabin, the coupling and the spare wheel(s) as well as the tools"

Previous EU definition of mass of the vehicle:

• Weight of car with fluids at 100% and fuel at 90%. Driver included in type approval and official documentation. However the defintion of "Mass of the vehicle" does not include driver, but the EU-Directive defines that the weight of the driver (75kg) shall be included in type approval applications. The weight is given for the base vehicle with no options mandatory for the kerb weight.
  

DIN/ISO Kerb Weight/Leergewicht DIN:

• DIN curb weight consists of vehicle, including 90% of fuel, driver, tool kit, warning triangle and spare tire (when fitted). Basically similar to EU curb weight definition. But as the old DIN weights did not include driver, I guess that when there is a reference from someone such as BMW, or others, to a "DIN curb weight" it can be assumed that it is without driver.
  
  
• As pointed out by Solstice in his Porsche weight examples; Leergewicht DIN is used when the curb weight without driver is stated.
  
  
• In German magazines the 1495-1500kg curb weight of the F8x is referred to as the DIN weight, further indicating that manufacturers use Leergewicht DIN as the standard for curb weight without driver.
  

A few real life examples:

Example 1: E92 M3

• US curb weight: 3704lbs/1681kg
• EU curb weight: 1655kg/1675kg (M6/DCT)

Here we can see that the US and EU weight doesn't match each other and there is a good reason why they don't.

EU weight of 1675kg includes DCT as that is stated in the BMW info, 1655kg is with the manual 6-speed. According to US legislation curb weight shall include options that is expected to be installed in at least 33% of vehicles sold.

That means added weight. And US fuel level is 100% as opposed to EU 90%, which adds 6,3l of fuel in the E92. So, if we take the EU 1655kg weight as a base (since that is the lightest known version of the std. E92 M3), the following makes the US weight end up at 1681kg:

• 1655kg
• + 20kg DCT
• + 4,5kg Fuel (extra 6,3l of fuel at 0,711kg/l)
• + 1,5kg Miscelaneous options
  
• 1681kg US curb weight

Example 2: F15 X5 and Cayenne

If we take the new X5 X-drive 35i for example these are the reported weights:

• bmwusa.com: 2125kg / 4680 lbs Curb weight
• bmw.de: 2030kg / 4475 lbs Leergewicht DIN
• bmw.de 2105kg / 4640 lbs Leergewicht EG

Here the 40 lbs US curb weight above Leergewicht EG (4680 vs 4640lbs) must again be due to the fact that US curb weight shall include optional equipment expected to be sold in more than 33% of the sold vehicles..

Now for comparison let's take the Porsche Cayenne.

• porsche.com/usa 1996kg / 4398 lbs Curb weight
• porsche.de 1995kg / 4398 lbs Leergewicht DIN
• porsche.de 2070kg / 4564 lbs Leergewicht EG

So if you just used the US curb weight you would get that the Cayenne is 4680 - 4398 = 282lbs / 128kg lighter (than the X5).

But look closer and you can see that the Cayenne's US curb weight reported is that of it's Leergewicht DIN (without driver and luggage) while the X5 is (Leergewicht EG + 40 lbs) which includes driver (75kg) and 40lbs optional equipment.

(The Cayenne is specified as a unique model with the tiptronic gearbox and is 35kg heavier than the manual car, which is also one difference between the Cayenne and X5.)

When comparing apples to apples the real difference is 4475 - 4398 = 77 lbs / 35kg. Which "strangely" also is the exact weight of the Tiptronic version of the Cayenne. So a Tiptronic Cayenne and a X5 35i, with similar transmissions, have the exact same curb weight/leergewicht

I.e US reported curb weight is not consistent but Leergewicht EG and DIN are consistent between these two German brands (just remember to compare comparable models/equipment levels).

UPDATE 12. June 2014:

The EU type approval number for the M3/M4 is:

e1*2007/46*0377*06

and

e1*2007/46*0377*07

These are the minimum weights listed in the type approval specs:

M3 DCT - 1560kg
M3 6MT - 1520kg

M4 DCT - 1537kg
M4 6MT - 1497kg


--------------------------------------------------------------------------------

Definitions have been removed from this post, but can be found here:

http://f80.bimmerpost.com/forums/sho...7&postcount=49

List of edits:
30.11.2013: The first sketch of the write up with only EU/DIN/ISO and US curb weights
01.12.2013: Added the new EU-legislation that repeals 92/21/EEC
02.12.2013: Added Leergewicht EG and Leergewicht DIN nomenclature to the definitions as well as added soltice's BMW X5 and Porsche examples
03.12.2013: Removed definitions from OP (can now be found in post #49 - see link below)
03.12.2013: Thanks to swamp2 and solstice for constructive input
12.06.2014: Added type approval numbers and listed minimum curb weights from type approval spec

[Chill72]

now you should take an older vehicle and post its weight as measured by different standards you wrote about. That way it will gives some hard numbers.

[CanAutM3]

So does the US curb weight inlude the driver?

[Boss330]

Originally Posted by CanAutM3

So does the US curb weight inlude the driver?

From the definition used by US authorities (and also Dept of Defence) Curb Weight does not include driver. The US definition of driver weight is 68kg.

http://www.nhtsa.gov/cars/rules/ruli...ervehicle.html


The NHTSA defines curb weight as follows:

NHTSA categorizes vehicles by class and “curb” weight. Curb
weight is the weight of a vehicle with standard equipment
including the maximum capacity of fuel, oil, coolant, and air
conditioning.

http://www.safercar.gov/Vehicle+Shop...r+FAQ#eighteen

Same as FMVSS:

http://www.fmcsa.dot.gov/rules-regul...aspx?reg=571.3

And:

Unloaded Vehicle Weight
· means the weight of a vehicle with maximum capacity of all fluids necessary for operation of the vehicle, but without cargo, occupants, or accessories that are ordinarily removed from the vehicle when they are not in use.

http://www.nasdpts.org/documents/pub...iniguide04.pdf

And from this mini guide to FMVSS regs:

Curb Weight: means the weight of a motor vehicle with standard equipment; Maximum capacity of fuel, oil, and coolant; and, if so equipped, air conditioning and additional weight of optional engine. Curb weight does not include the driver, passengers, or cargo.

http://opi.mt.gov/PDF/PupilTransport/PTHAppI.pdf

[solstice]

The summary is that you need to check each curb weight number given by the manufaturer in the US. Some include the driver, i.e they report "Unladen EU" weight others report the US definiton or Unladen DIN without driver. It's even more confusing because the same manufacturer is not neccessarily consistent in how they report curb weight in the US data sheets.

This is the standards compressed:

Curb Weight = Weight of Car with standard accessories, full fluids, no driver
Unladen EU Weight = Weight of Car with 90% fuel, 68 kg driver, 7 kg cargo
Unladen DIN Weight = Weight of Car with 90% fuel, no driver, no cargo

1 US Gallon = 3.8 liters
Weight of 1 US Gallon of Gasoline = 6.35 pounds (2.87 kg)
Weight of 1 liter of Gasoline = 1.67 pounds (0.76 kg)

---------------------

We refer a lot to the E92 M3 here.

Unladen EU ( with driver and luggage ): 1655 kg / 3649 lbs
US reported Curb weight: 3704 lbs

Here BMW has obviously inlcuded the driver and luggage in their reported US Curb weight. The 55 lbs difference could be DCT.

-------------------

The number we have for the M4 is 1500kg Unladen DIN.
The E92 M3 Unlade DIN is 1655 - 68 - 7 = 1580 kg or exactly 80kg more than the M4.

--------------------

[pkimM3r]

So add in dct for an additional 70kg and the m4 is only 10kg lighter than an e92 manual?!

[solstice]

Originally Posted by pkim1079

So add in dct for an additional 70kg and the m4 is only 10kg lighter than an e92 manual?!

If the M4's DCT is 70 kg heavier than the M4's manual then yes. 70kg sounds like a lot though. Is the new DCT really that much heavier than the new MT? The E92 M3 difference between MT and DCT was around 22 kg I think.

[nonagon]

Originally Posted by pkim1079

So add in dct for an additional 70kg and the m4 is only 10kg lighter than an e92 manual?!

No

[swamp2]

Originally Posted by CanAutM3

So does the US curb weight inlude the driver?

It appears there are 2 answers. There are official/governmental definitions and then there is whatever the manufacturer wishes to do (no surprise). In the case of BMW it appears quite certain that the numbers include driver but BMW typically uses "Unladen weight" in US specification sheets.

Anything to add on this "unladen" thing Boss330?

Originally Posted by Boss330

US Curb Weight:

• Weight of car with fluids and fuel at 100% as well as weight of any option expected to be in more than 33% of vehicles sold. Driver not included in US legal defintion, but usually included in manufacturers public figures.

[swamp2]

Boss330? Thanks so much for the write up. It is very useful. I will suggest it as a sticky.

[swamp2]

Originally Posted by solstice

The summary is that you need to check each curb weight number given by the manufaturer in the US. Some include the driver, i.e they report "Unladen EU" weight others report the US definiton or Unladen DIN without driver. It's even more confusing because the same manufacturer is not neccessarily consistent in how they report curb weight in the US data sheets.

Is it really this bad? How/against what can a manufacturers figure be checked?

All BMW numbers on the US web site now appear to be "Unladen", however, I'm sure I've seen them use other specifications in the past.

[CanAutM3]

Originally Posted by pkim1079

So add in dct for an additional 70kg and the m4 is only 10kg lighter than an e92 manual?!

IMO, a F8X DCT would be around 70lb heavier than a manual, not 70kg.

The DCT is 20kg (45lb) heavier on the E9X plus they were able to shave 12kg (26lb) on the F8X 6MT for a 32kg difference (70lb). This is assuming that the new DCT is not heavier than the previous gen.

[pkimM3r]

Arent the numbers floating around 70kg though? I do agree with you though more than a hundred pound difference is quite steep.

Im just wondering if this weight savings is just a bunch of bullshit. All this mumbo jumbo on weight savings and its just how you spin a story.

Thats all.

[pkimM3r]

Originally Posted by nonagon

No

Please elaborate lol.

[solstice]

Originally Posted by swamp2

Is it really this bad? How/against what can a manufacturers figure be checked?

All BMW numbers on the US web site now appear to be "Unladen", however, I'm sure I've seen them use other specifications in the past.

It's not that bad but since inconsistency do exist it's very hard to know which numbers are what without doing some research. The european reporting seems to be much more consistent and reliable by the European brands. The "checking" I refer to is to lookup the European numbers. I usually start with the official German web sites for the manufacturer and in some cases verify with other European countries web sites. Hopefully we will see more consistency in the future of US weight reporting.

If we take the new X5 X-drive 35i for example these are the reported weights:

bmwusa.com: 4680 lbs Curb weight
bmw.de: 2030kg / 4475 lbs Leergewicht DIN
bmw.de 2105kg / 4640 lbs Leergewicht EG

So for the X5 it looks similar to the E92 M3 where driver + luggage is included in the curb weight to get to a 40 lbs above Leergewicht EG.

Now for comparison let's take the Porsche Cayenne.

porsche.com/usa 4398 lbs Curb weight
porsche.de 1995kg/ 4398 lbs Leergewicht DIN
porsche.de 2070kg/ 4564 lbs Leergewicht EG

So if you just used the US curb weight you would get that the Cayenne is 4680 - 4398 = 282 lbs ligther.
But look closer and you can see that the Cayenne's curb weight reported is that of it's Leergewicht DIN ( without driver and luggage ) while the X5 is (Leergewicht EG + 40 lbs) which inlcudes driver and luggage.

When comparing apples to apples the real difference is 4475 - 4398 = 77 lbs.
I.e US reported curb weight is not consistent but Leergewicht EG and DIN are consistent between these two German brands.

[Ezio]

hummmm

[Boss330]

Originally Posted by Ezio

hummmm

???

[Boss330]

Originally Posted by swamp2

It appears there are 2 answers. There are official/governmental definitions and then there is whatever the manufacturer wishes to do (no surprise). In the case of BMW it appears quite certain that the numbers include driver but BMW typically uses "Unladen weight" in US specification sheets.

Anything to add on this "unladen" thing Boss330?

Yes, that is one of the things I have tried to find out more info about. It's probably "hidden" in some legislation or similar, but I haven't the detailed knowledge of US legislation (more familiar with EU-legislation).

This is one of the things I will try to find out more about and whether the US manufacturers use different standards when stating curb weight.

With the F8x it seems 100% clear that the 1495-1500kg curb weight is with 90% fuel, fluids and in the base Version, but WITHOUT driver. Which is a bit misleading since they allways use curb weight with driver elsewhere...

[CanAutM3]

Originally Posted by solstice

It's not that bad but since inconsistency do exist it's very hard to know which numbers are what without doing some research. The european reporting seems to be much more consistent and reliable by the European brands. The "checking" I refer to is to lookup the European numbers. I usually start with the official German web sites for the manufacturer and in some cases verify with other European countries web sites. Hopefully we will see more consistency in the future of US weight reporting.

If we take the new X5 X-drive 35i for example these are the reported weights:

bmwusa.com: 4680 lbs Curb weight
bmw.de: 2030kg / 4475 lbs Leergewicht DIN
bmw.de 2105kg / 4640 lbs Leergewicht EG

So for the X5 it looks similar to the E92 M3 where driver + luggage is included in the curb weight to get to a 40 lbs above Leergewicht EG.

Now for comparison let's take the Porsche Cayenne.

porsche.com/usa 4398 lbs Curb weight
porsche.de 1995kg/ 4398 lbs Leergewicht DIN
porsche.de 2070kg/ 4564 lbs Leergewicht EG

So if you just used the US curb weight you would get that the Cayenne is 4680 - 4398 = 282 lbs ligther.
But look closer and you can see that the Cayenne's curb weight reported is that of it's Leergewicht DIN ( without driver and luggage ) while the X5 is (Leergewicht EG + 40 lbs) which inlcudes driver and luggage.

When comparing apples to apples the real difference is 4475 - 4398 = 77 lbs.
I.e US reported curb weight is not consistent but Leergewicht EG and DIN are consistent between these two German brands.

I wonder why BMW would want to advertise their cars as heavier than they are in the US. If the regulatory definition of "curb weight" in the US is without a driver, why add it to your advertised specs ?

[Boss330]

EDIT

Added the new EU legislation that repeals 92/21/EEC, and replaced it with commision regulation 1230/2012 that implements regulation 661/2009 with regards to masses and dimensions.

[Diver]

Driver @ 75 kg, whoops, I am off spec.

[Cuz5150]

Thanks for all this info, my head hurts/