Curb weight - what does it really mean ??

MvM · 25 September 2006

There have been many threads in the past about the weight of this or that NSX. Some of the members here have gone to extreme length to minimise the weight of their car and have stated the weight of their car compared what the official 'curb weight' is.

I was wondering exactly what the 'curb weight' of a car is suppose to mean.

Is it the weight of the car including a full tank of fuel, or half-full or without any fuel. What about the weight of windscreen washer fluids or cooling fluids ??

I had my car weighed today. I fully filled up my fuel tank first so I would know the total weight of fuel. The fuel tank of the NSX holds 70 liters which equals to about 50.4 kg (or 111.1 lbs).
Fully loaded and with an empty trunk and no passengers the total weight was measured at 1360 kg (2998 lbs).
So, with an empty tank that would be 1310 kg or 2888 lbs.

john@johnhudakracing · 25 September 2006

MvM said:
There have been many threads in the past about the weight of this or that NSX. Some of the members here have gone to extreme length to minimise the weight of their car and have stated the weight of their car compared what the official 'curb weight' is.

I was wondering exactly what the 'curb weight' of a car is suppose to mean.

Is it the weight of the car including a full tank of fuel, or half-full or without any fuel. What about the weight of windscreen washer fluids or cooling fluids ??

I had my car weighed today. I fully filled up my fuel tank first so I would know the total weight of fuel. The fuel tank of the NSX holds 70 liters which equals to about 50.4 kg (or 111.1 lbs).
Fully loaded and with an empty trunk and no passengers the total weight was measured at 1360 kg (2998 lbs).
So, with an empty tank that would be 1310 kg or 2888 lbs.

This is an often misunderstood topic. There are several terms-

'Curb Weight' - Curb (Kerb) weight is the total weight of an automobile with standard equipment, oil, lubricants, coolant, a full tank of fuel and not loaded with either passengers or cargo. It is also referred to more specifically as the 'wet curb weight'.

'Dry weight' is the weight of an automobile with standard equipment, no oil, lubricants, coolant, or fuel and not loaded with either passengers or cargo.

'Race weight or Scale Weight' A race term, it is the weight as would normally be found on a set of scales while doing suspension setup, typically the Curb Weight plus a variable amount of ballast representing the driver.

'Gross Vehicle Weight' (GVWR) - Put simply, GVWR is a vehicle when fully loaded with passengers and/or cargo. The GVWR is the maximum a loaded vehicle can weigh, with fuel, passengers, luggage, "stuff" in the cabin, and in the case of trucks... also items in the bed, tool box, trailer hitch(s), and trailer hitch weight on the 5th-wheel hitch or on the receiver hitch. he gross vehicle weight restriction (GVWR) is a term used by vehicle manufacturers to indicate the maximum amount of weight the vehicle is designed to handle. The door-frame placard will probably use this abbreviation. The limiting factor of the vehicle might be the strength of the frame, struts or suspension, tires, or drive train components. Knowing the GVWR is designed to assist a vehicle owner to not break the vehicle by overloading it. Trucks may further list a GCWR - Relevant for trucking and closely related, it is the maximum combined weight of your loaded tow vehicle, and the loaded trailer.

'Payload' - The payload is the difference between the GVWR and the empty but "wet" vehicle before you add driver, passengers, luggage, cargo, and hitch weight. [Wet means full of fuel and all other fluids needed to drive the vehicle).

- You are correct that in the instance of the NSX, since it has an 18.5 gallon fuel tank and it falls into the 2400-3200 range as a production vehicle- the difference between wet and dry is a significant percentage of the total vehicle weight. Depending on Octane and ambient temp, 1 gallon of gasoline equals 5.8 to 6.5 lbs, edging towards the top end for the Premium pump fuel most use, or 112.85-115.625 per tank or so. For performance purposes, all measurements need to be as accurate as possible for calculations and setup, thus the race weight is what is most relevant. IN general, be weary of quoted weights, as it is often a source of inaccuracies in forum discussions.

darknezz_ghost · 26 September 2006

i'm just wondering.. is your vehicle all stock?? or does it have some aftermarket parts to it cuz it'll decrease the weight.. thanks..

53heloFE · 26 September 2006

MvM said:
I was wondering exactly what the 'curb weight' of a car is suppose to mean.

Excellent question :smile:

53heloFE · 26 September 2006

John@Microsoft said:
This is an often misunderstood topic. There are several terms-

'Curb Weight' - Curb (Kerb) weight is the total weight of an automobile with standard equipment, oil, lubricants, coolant, a full tank of fuel and not loaded with either passengers or cargo. It is also referred to more specifically as the 'wet curb weight'.

'Dry weight' is the weight of an automobile with standard equipment, no oil, lubricants, coolant, or fuel and not loaded with either passengers or cargo.

'Race weight or Scale Weight' A race term, it is the weight as would normally be found on a set of scales while doing suspension setup, typically the Curb Weight plus a variable amount of ballast representing the driver.

'Gross Vehicle Weight' (GVWR) - Put simply, GVWR is a vehicle when fully loaded with passengers and/or cargo. The GVWR is the maximum a loaded vehicle can weigh, with fuel, passengers, luggage, "stuff" in the cabin, and in the case of trucks... also items in the bed, tool box, trailer hitch(s), and trailer hitch weight on the 5th-wheel hitch or on the receiver hitch. he gross vehicle weight restriction (GVWR) is a term used by vehicle manufacturers to indicate the maximum amount of weight the vehicle is designed to handle. The door-frame placard will probably use this abbreviation. The limiting factor of the vehicle might be the strength of the frame, struts or suspension, tires, or drive train components. Knowing the GVWR is designed to assist a vehicle owner to not break the vehicle by overloading it. Trucks may further list a GCWR - Relevant for trucking and closely related, it is the maximum combined weight of your loaded tow vehicle, and the loaded trailer.

'Payload' - The payload is the difference between the GVWR and the empty but "wet" vehicle before you add driver, passengers, luggage, cargo, and hitch weight. [Wet means full of fuel and all other fluids needed to drive the vehicle).

- You are correct that in the instance of the NSX, since it has an 18.5 gallon fuel tank and it falls into the 2400-3200 range as a production vehicle- the difference between wet and dry is a significant percentage of the total vehicle weight. Depending on Octane and ambient temp, 1 gallon of gasoline equals 5.8 to 6.5 lbs, edging towards the top end for the Premium pump fuel most use, or 112.85-115.625 per tank or so. For performance purposes, all measurements need to be as accurate as possible for calculations and setup, thus the race weight is what is most relevant. IN general, be weary of quoted weights, as it is often a source of inaccuracies in forum discussions.

Excellent answers, very informative. :smile:

MvM · 26 September 2006

darknezz_ghost said:
i'm just wondering.. is your vehicle all stock?? or does it have some aftermarket parts to it cuz it'll decrease the weight.. thanks..

Thanks for asking and no, the car is not stock anymore.

I cannot upload an excel-sheet with all the (possible) changes but I can list them:

Item LBS KG
OEM spare-tire (15", model 1991-1996) Remove -29.4 -13.3
OEM spare tire mount Remove -2.2 -1.0
OEM European toolkit (no pump&jack) Remove -6.6 -3.0
OEM towhook Remove -0.8 -0.3
OEM European foglights (pair) Remove -3.6 -1.6
OEM Zanardi floormat set Add 6.4 2.9
OEM Alpine 6-disc CD-player (in trunk) Add 4.3 1.9
OEM Alpine CD-player mount Add 2.4 1.1
OEM Honda battery 65Ah Remove -37.0 -16.8
OEM Honda battery 45Ah Add 33.0 15.0
OEM engine cover NSX coupe version Remove -13.9 -6.3
Carbonfiber mesh engine cover Add 5.3 2.4
OEM suspension 1991-1996 all wheels Remove -55.3 -25.1
TEIN-RA suspension Add 41.7 18.9
OEM (1991-1994) Remove -43.4 -19.7
SoS Taitec GT Lightweight Add 18.3 8.3
OEM headers (1991-1996) Remove -32.0 -14.5
SoS Taitec GT headers (1991-1994) Add 19.4 8.8
OEM front wheel 16x7 (1994-2001) Remove -33.6 -15.2
OEM rear wheel 17x8.5 1994+ Remove -41.8 -19.0
BBS RSII front wheel 17x8 Add 46.0 20.9
BBS RSII rear wheel 18x10 Add 50.2 22.8
OEM front rotor 1991-1996 11.1" Remove -27.8 -12.6
Stoptech Aerorotor front 1991-1996 Add 24.6 11.2
OEM side air-intake (set) Remove -5.0 -2.3
OEM air intake tube Remove -1.3 -0.6
OEM Rear Toelinks rear Remove -2.1 -1.0
Dali Racing carbonglass air-intake Add 1.0 0.5
Dali Racing radiator shield Add 2.1 1.0
Cantrell air intake Add 4.5 2.0
SOS Non-compliance Toelinks Add 1.7 0.8
Home made Front Underbody Cover (Type R) Add 3.2 1.5

Total weight saved according to my calculations is 72 Lbs or 32.5 Kg.

goldNSX · 26 September 2006

Thanks for the weight table. Mine was with full tank AND 75 kg driver 1440 kg, or 1365 without the driver.

According to your list:

OEM spare-tire (15", model 1991-1996) Remove -29.4 -13.3
OEM spare tire mount Remove -2.2 -1.0
OEM Zanardi floormat set Add 6.4 2.9
OEM Alpine 6-disc CD-player (in trunk) Add 4.3 1.9
OEM Alpine CD-player mount Add 2.4 1.1
OEM headers (1991-1996) Remove -32.0 -14.5
SoS Taitec GT headers (1991-1994) Add 19.4 8.8
OEM front wheel 16x7 (1994-2001) Remove -33.6 -15.2
OEM rear wheel 17x8.5 1994+ Remove -41.8 -19.0
Rays front wheel 17x8 Add 20
Rays rear wheel 18x10 Add 24
Cantrell AIS Add 4.5 2.0

Did you weight with the driver?

MvM · 26 September 2006

goldNSX said:
Thanks for the weight table. Mine was with full tank AND 75 kg driver 1440 kg, or 1365 without the driver.

According to your list:

OEM spare-tire (15", model 1991-1996) Remove -29.4 -13.3
OEM spare tire mount Remove -2.2 -1.0
OEM Zanardi floormat set Add 6.4 2.9
OEM Alpine 6-disc CD-player (in trunk) Add 4.3 1.9
OEM Alpine CD-player mount Add 2.4 1.1
OEM headers (1991-1996) Remove -32.0 -14.5
SoS Taitec GT headers (1991-1994) Add 19.4 8.8
OEM front wheel 16x7 (1994-2001) Remove -33.6 -15.2
OEM rear wheel 17x8.5 1994+ Remove -41.8 -19.0
Rays front wheel 17x8 Add 20
Rays rear wheel 18x10 Add 24
Cantrell AIS Add 4.5 2.0

Did you weight with the driver?

Thanks for your update.
Like you I have heavy wheels, they add about 9.4Kg to the total weight of the car in my case. Your Rays wheels are about as heavy. Am still thinking about switch to OZ Superleggera or Ultralegerra.

I did not weigh with the driver (in my case only about 63 Kg). So in my case it would be 1423 Kg with driver.
If you know your base weight you can add or substract anything to the sheet (list). I do try to weigh as much parts as I can but it's not always possible.
For instance, I found the Taitec GTLW to be heavier than mentioned on the ScienceofSpeed website (8.3 kg instead of 7.3 kg).

goldNSX · 26 September 2006

MvM said:
Thanks for your update.
Like you I have heavy wheels, they add about 9.4Kg to the total weight of the car in my case. Your Rays wheels are about as heavy. Am still thinking about switch to OZ Superleggera or Ultralegerra.

I did not weigh with the driver (in my case only about 63 Kg). So in my case it would be 1423 Kg with driver.
If you know your base weight you can add or substract anything to the sheet (list). I do try to weigh as much parts as I can but it's not always possible.
For instance, I found the Taitec GTLW to be heavier than mentioned on the ScienceofSpeed website (8.3 kg instead of 7.3 kg).

Adding lighter wheels AND tires (Procar or Volk Racing/Dunlop) would save me about 18 kg for a few thousend $. This would be the only thing I would do because the weight really counts there. IMO weight-saving parts are ONLY COSMETICAL unless they really modify the car like header/exhaust, suspension and wheels. It's quite hard to loose 50 kg on the NSX without compromise in comfort which is a matter of personal preferences. (It's no fun driving her at 35 degrees outside temp without A/C

)

Well, the guy who drove the car on the weight station was 75 kg, not me.

Your weight list is far more complete than mine.

Congrats! I've bookmarked this thread.

MvM · 26 September 2006

goldNSX said:
Your weight list is far more complete than mine. Congrats! I've bookmarked this thread.

Thanks for the compliment.
Actually, the OZ wheels are not so very expensive. It's just that I think the BBS RSII wheels look really good on my car.

As for different weights, it you private me your email-address, I can send you the spreadsheet that I use to calculate the weight of the car.

AU_NSX · 27 September 2006

MvM said:
I had my car weighed today. I fully filled up my fuel tank first so I would know the total weight of fuel. The fuel tank of the NSX holds 70 liters which equals to about 50.4 kg (or 111.1 lbs).
Fully loaded and with an empty trunk and no passengers the total weight was measured at 1360 kg (2998 lbs).
So, with an empty tank that would be 1310 kg or 2888 lbs.

This information together with your list of individual parts weights is some invaluable information! I too think there is a lot of mis-information about the weight of even a standard NSX!

I never weighed the items removed or replaced on my car! This list is excellent!

Thanks so very much for posting this!

goldNSX · 27 September 2006

Your Excel sheet is GREAT! Congrats!

Greg Z · 16 October 2006

goldNSX said:
Adding lighter wheels AND tires (Procar or Volk Racing/Dunlop) would save me about 18 kg for a few thousend $. This would be the only thing I would do because the weight really counts there. IMO weight-saving parts are ONLY COSMETICAL unless they really modify the car like header/exhaust, suspension and wheels. It's quite hard to loose 50 kg on the NSX without compromise in comfort which is a matter of personal preferences. (It's no fun driving her at 35 degrees outside temp without A/C )

Well, the guy who drove the car on the weight station was 75 kg, not me.

Your weight list is far more complete than mine. Congrats! I've bookmarked this thread.

I've bookmarked this page also, thnx for the great info. How much do the Volk Racing w/ Dunlops 18/17 weigh verses the OEM's?

Curb weight - what does it really mean ??

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