[No Doubt]

This is one of those seemingly simple and frequently asked questions that should have an equally simple and straight forward answer, but in reality it's not so simple.

The 2008 Z06 curb weight can vary depending on option package. For example, either 1LZ, 2LZ or 3LZ. According to Chevrolet | 2008 Corvette - Performance Specs the 2008 Z06 curb weight is 3,162 lbs. Notice that no other weight is given and no allowance is made for the difference in weight among the three packages. That is called a "clue" <cough>marketing<cough>.

The C5 Z has a curb weight of 3,118 lbs. Once again according to GM.

Those weights were obtained with the amount of fuel GM used to calculate them, not necessarily the amount put in at the Bowling Green assembly plant and not the amount you or I might use. Hence, owner results may vary depending on the amount of fuel and/or aftermarket equipment aboard.

Curb weight is defined as vehicle weight will full fuel, oil and without driver, passengers or cargo. However, some manufacturers, such as GM, make this calculation based on a specific amount of fuel, but less than full. Conversely, Porsche calculates curb weight with no fuel, or dry curb weight (marketing again).

Gross Vehicle Weight Rating (GVWR) is the maximum allowable weight, including all necessary operating fluids and equipment, fuel, cargo, driver, passengers and trailer tongue weight.

 

[No Doubt]

"Curb weight" should indicate only one thing, as above. However, once again, manufacturers don't always measure curb weight in the same manner.

GM uses an unknown amount of fuel and Porsche uses no fuel. Although both market vehicle weight as "curb weight" they're not the same because they're defining 'curb weight' differently.

GM claims the Z06 weighs a given amount, but again makes no distinction between the various package weights. Cars equipped with a 1LZ, 2LZ or 3LZ do not all weigh the same. For example, a 3LZ equipped car almost certainly weighs measurably more than a 1LZ equipped car.

We know about how much fuel they put in at Bowling Green, but that doesn't mean engineering or marketing used that same amount in order to calculate curb weight.

I have weighed my Z06s using accurate 4 corner racing scales and I know how much they weighed at the time. However, I only knew approximately how much fuel was onboard at the time.

One must use a measured and precise quantity of fuel in order to compare two otherwise identical cars. GM does that. Every Z06 that comes off the line at Bowling Green, if optioned the same, weighs the same. If they add the same amount of fuel to each then they will still weigh the same. One does not miraculously weigh 200 pounds less than the other does after delivery if both have the same amount of fuel they had aboard when they came off the line.

Marketing:

When GM says the 2008 Z06 weighs X lbs, which car are they referring to?

Again, GM does not make a public distinction between the three available option packages and their respective curb weights.

I wouldn't be surprised if GM uses the 2008 Z06 equipped with the 1LZ package as the weight specification in marketing materials since it should be the lightest of the three packages.

A simple experiment

Take a 2008 Z06 equipped with the 1LZ package and full (measured) fuel and weigh it.

Measured weight =

Take a 2008 Z06 equipped with the 3LZ package and full (measured) fuel and weigh it.

Measured weight =

Hypothesis:

The 3LZ equipped car should weigh more.

Next time someone asks how much a Z06 weighs, you might want to think about the answer.