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The issue of weight often crops up in discussions about cars, and I think there's a lack of understanding which often leads to poor comparison*. All too often, manufacturers quote a car's "dry" weight (without driver, fluids, or fuel), a metric which bears no resemblance to its weight in working order.
Calculating a car's operational weight from its dry weight requires that you have a copy of its owner's manual at the ready, in addition to relevant product literature about its various coolants, fluids and oils. This may seem insignificant, but the difference between a test weight and dry weight can be as much as 200 kg (a driver and a full fuel tank account for roughly 140 kg alone); without knowing it, we might be comparing vehicles unfairly.
Luckily, magazines regularly measure a vehicle's weight for road tests; the result is a more realistic picture of kerb weight. Unfortunately, stark differences between magazines can muddy the waters of our understanding. In the following example, extreme differences in reported kerb weight can be seen:
Lamborghini Gallardo LP570-4 Superleggera
Auto (Italy): 1592 kg (700 kg front, 892 kg rear)
Auto Motor und Sport: 1484 kg
Automobilismo: 1542.8 kg (658.6 kg front, 884.2 kg rear)
Sport Auto: 1493 kg
The biggest discrepancy is a whopping 98 kg! Most would assume that surely these magazines use different methods for measuring/reporting vehicle kerb weights; a valid assumption were it not for the fact that these same tests were conducted for the Ferrari 458 Italia, which led to the following numbers:
Auto (Italy): 1528 kg (651 kg front, 877 kg rear)
Auto Motor und Sport: 1544 kg
Automobilismo: 1544.0 kg (657.2 kg front, 886.8 kg rear)
Sport Auto: 1540 kg
That's a maximum kerb weight discrepancy of just 16 kg, or just about about one percent. In this instance, the numbers are very consistent. The conclusion we should draw from the Ferrari 458 numbers is that the magazines use the same methodology for reporting or measuring weight - something which sits in stark contrast to the conclusions reached above.
Clearly, a car's measured kerb weight changes based on fuel level (at a density of 0.755 kg/L, a 90 L fuel tank accounts for about 68 kg of mass) and number of occupants (the agreed-upon standard appears to be 70 or 75 kg). I would therefore like to know exactly how these factors are controlled for in each magazine's measurements. For instance, the DIN standard for kerb weight measurements clearly specifies 90% fuel and no occupants; whereas the EU standard retains the same fuel level and adds a 75 kg driver.
If we can standardize these measurements, it would be enormously beneficial for making an accurate comparison between vehicles. As we determine each magazine's method of kerb weight reporting, I'll update the list below to reflect that.
DIN standard: 90% fuel; no driver
EU standard: 90% fuel; 75 kg driver
Auto (Italy):
AutoBild:
Autocar:
Automobilismo:
Auto Motor und Sport:
AutoZeitung:
Car and Driver:
Quattroruote:
Road and Track:
Sport Auto:
Sport Auto (France):
*not the least of which is the fact that people frequently confuse weight with mass; the former is a force which results from a gravitational field, the other is a measurement of linear inertia.
DIN standard: 90% fuel; no driver
EU standard: 90% fuel; 75 kg payload (68 kg driver, 7 kg luggage)
Auto (Italy):
AutoBild (and AutoBild Sportscars): 100% fuel; no driver
Autocar:
Automobilismo:
Auto Motor und Sport: 100% fuel; no driver
AutoZeitung: 100% fuel; no driver
Car and Driver:
Quattroruote: 100% fuel; 100 kg payload (driver and instruments)
Road and Track:
Sport Auto: 100% fuel; no driver
Sport Auto (France):
List Updated:
DIN standard: 90% fuel; no driver
EU standard: 90% fuel; 75 kg payload (68 kg driver, 7 kg luggage)
Auto (Italy):
AutoBild (and AutoBild Sportscars): 100% fuel; no driver
Autocar:
Automobilismo:
Auto Motor und Sport: 100% fuel; no driver
AutoZeitung: 100% fuel; no driver
Car and Driver:
Quattroruote: 100% fuel; 100 kg payload (driver and instruments)
Road and Track:
Sport Auto: 100% fuel; no driver
Sport Auto (France):
Calculating a car's operational weight from its dry weight requires that you have a copy of its owner's manual at the ready, in addition to relevant product literature about its various coolants, fluids and oils. This may seem insignificant, but the difference between a test weight and dry weight can be as much as 200 kg (a driver and a full fuel tank account for roughly 140 kg alone); without knowing it, we might be comparing vehicles unfairly.
Luckily, magazines regularly measure a vehicle's weight for road tests; the result is a more realistic picture of kerb weight. Unfortunately, stark differences between magazines can muddy the waters of our understanding. In the following example, extreme differences in reported kerb weight can be seen:
Lamborghini Gallardo LP570-4 Superleggera
Auto (Italy): 1592 kg (700 kg front, 892 kg rear)
Auto Motor und Sport: 1484 kg
Automobilismo: 1542.8 kg (658.6 kg front, 884.2 kg rear)
Sport Auto: 1493 kg
The biggest discrepancy is a whopping 98 kg! Most would assume that surely these magazines use different methods for measuring/reporting vehicle kerb weights; a valid assumption were it not for the fact that these same tests were conducted for the Ferrari 458 Italia, which led to the following numbers:
Auto (Italy): 1528 kg (651 kg front, 877 kg rear)
Auto Motor und Sport: 1544 kg
Automobilismo: 1544.0 kg (657.2 kg front, 886.8 kg rear)
Sport Auto: 1540 kg
That's a maximum kerb weight discrepancy of just 16 kg, or just about about one percent. In this instance, the numbers are very consistent. The conclusion we should draw from the Ferrari 458 numbers is that the magazines use the same methodology for reporting or measuring weight - something which sits in stark contrast to the conclusions reached above.
Clearly, a car's measured kerb weight changes based on fuel level (at a density of 0.755 kg/L, a 90 L fuel tank accounts for about 68 kg of mass) and number of occupants (the agreed-upon standard appears to be 70 or 75 kg). I would therefore like to know exactly how these factors are controlled for in each magazine's measurements. For instance, the DIN standard for kerb weight measurements clearly specifies 90% fuel and no occupants; whereas the EU standard retains the same fuel level and adds a 75 kg driver.
If we can standardize these measurements, it would be enormously beneficial for making an accurate comparison between vehicles. As we determine each magazine's method of kerb weight reporting, I'll update the list below to reflect that.
DIN standard: 90% fuel; no driver
EU standard: 90% fuel; 75 kg driver
Auto (Italy):
AutoBild:
Autocar:
Automobilismo:
Auto Motor und Sport:
AutoZeitung:
Car and Driver:
Quattroruote:
Road and Track:
Sport Auto:
Sport Auto (France):
*not the least of which is the fact that people frequently confuse weight with mass; the former is a force which results from a gravitational field, the other is a measurement of linear inertia.
DIN standard: 90% fuel; no driver
EU standard: 90% fuel; 75 kg payload (68 kg driver, 7 kg luggage)
Auto (Italy):
AutoBild (and AutoBild Sportscars): 100% fuel; no driver
Autocar:
Automobilismo:
Auto Motor und Sport: 100% fuel; no driver
AutoZeitung: 100% fuel; no driver
Car and Driver:
Quattroruote: 100% fuel; 100 kg payload (driver and instruments)
Road and Track:
Sport Auto: 100% fuel; no driver
Sport Auto (France):
List Updated:
DIN standard: 90% fuel; no driver
EU standard: 90% fuel; 75 kg payload (68 kg driver, 7 kg luggage)
Auto (Italy):
AutoBild (and AutoBild Sportscars): 100% fuel; no driver
Autocar:
Automobilismo:
Auto Motor und Sport: 100% fuel; no driver
AutoZeitung: 100% fuel; no driver
Car and Driver:
Quattroruote: 100% fuel; 100 kg payload (driver and instruments)
Road and Track:
Sport Auto: 100% fuel; no driver
Sport Auto (France):
