In short
- Kerb weight, unladen weight and mass in running order are different definitions.
- Current UK mass-in-running-order guidance includes a driver and a full fuel tank.
- A model range can cover different transmissions, body styles and fitted equipment.
- The correct poster figure is the checked value for the exact version drawn.
Weight looked like the least arguable line on a car poster until I began checking it. One source includes a driver, another does not. One lists a range across several versions. The number can be correct on its own terms and still be wrong for the car I drew.
Why do kerb weights vary for the same car?
Kerb weights vary when sources use different definitions or describe different versions of the car. Compare the included fuel, driver, equipment, body style, transmission and market before comparing the kilograms.
The mistake is to treat “weight” as one field with one agreed meaning. UK rules distinguish unladen weight, kerb weight and mass in running order. A manufacturer can also publish a range because one model name covers more than one physical specification.
What do the common vehicle weight terms include?
Kerb weight, unladen weight and mass in running order do not contain the same things. The source’s definition must stay beside the number.
| Term | Includes | Leaves out or varies |
|---|---|---|
| UK kerb weight | Full fuel, operating fluids, normal loose equipment | People and load |
| UK unladen weight | Body and parts normally used on the road | Fuel, people and load |
| UK mass in running order | Driver, normal parts, fluids and full fuel | Passengers, goods and other items |
| EU mass in running order | Driver, at least 90% fuel, fluids and standard equipment | Optional equipment unless included in actual mass |
Why can one model have a minimum and maximum weight?
A model range can contain different transmissions, body styles, markets and fitted equipment. The published minimum and maximum describe the range, not one anonymous car.
A useful comparison names the version on both sides. If a brochure lists a span, the next job is to find where the exact car sits inside it. Copying the minimum because it looks tidy is not verification.
This is why a normal difference inside a credible range does not need a dramatic correction. The 350Z buyer’s guide keeps its catalogue weight tied to the drawn HR car rather than presenting it as every 350Z.
Which kerb weight belongs on a car poster?
The poster needs the checked figure for the exact model year, market and specification drawn. A plausible number from another version is still the wrong number.
Jonathan’s finished portraits are the starting point because they contain the figures customers have already bought. I still query a figure that falls outside the published range for the car. Ordinary source variation stays ordinary. An impossible value stops the work until it is resolved.
The specification-checking guide shows that decision in full. You can also open a catalogue poster and see the figure in the same layout that goes to the print file.
What are the sources and limits of these definitions?
GOV.UK supplies the current public definitions for unladen weight and mass in running order. UK construction rules define kerb weight, while current European regulation explains mass in running order and actual vehicle mass.
Read the GOV.UK guide to vehicle weights, the UK kerb-weight definition quoted by HMRC, and the current European mass definitions. These definitions explain why labels differ. They do not identify the correct weight of an individual car without its own specification.
Questions people actually ask
- Why does the same car have different kerb weights?
- The figures may describe different body styles, transmissions, markets or equipment. Sources can also use different definitions, so check what the quoted weight includes before treating two numbers as a disagreement.
- Does kerb weight include the driver in the UK?
- The UK construction-rule definition of kerb weight says no person is carried. Mass in running order is different: current GOV.UK guidance for cars includes the driver, normal parts, essential fluids and a full fuel tank.
- What is the difference between kerb weight and unladen weight?
- Under the UK definitions, kerb weight includes a full fuel tank and the fluids needed to run, while unladen weight excludes fuel. Neither figure includes passengers or ordinary luggage.
- Which weight goes on a Greasemonkey Prints poster?
- The poster uses the signed figure for the exact drawn version. Jonathan checks the label, model year, market and configuration, then records the source instead of choosing the lightest value in a published range.
Written by Jonathan in Derby. Last updated .