When it comes to weighing vehicles on the road, it can get pretty confusing. There are kerb weights, GVWR weights, GAWR, and GCWR. It's easy to get a little confused as to what weight means. Fortunately, kerb weight (also known as curb weight) is one of the simplest terms. So, if someone asks you what is minimum kerb weight? you don’t have to break out a calculator.
Minimum kerb weight in a vehicle is the weight of the vehicle with an empty fuel tank. Normally, when you hear the term kerb weight, it's referring to the empty weight of the vehicle with a half or a full tank of gas. Minimum kerb weight is the weight of the vehicle with no gas in the tank.
When we say minimum, it's the absolute minimum. There is nothing in the vehicle at all. It is empty. Minimum does not include most other fluids, such as brake fluid, coolant, power steering, and transmission fluids. It just means the weight of an empty car with an empty gas tank.
What is kerb weight?
When someone mentions the term kerb weight, it usually means the vehicle’s weight without anything else, such as passengers or cargo. Most of the time, kerb weight includes either half a tank of gasoline or diesel or a full tank.
Minimum kerb weight removes the gas or diesel, and that’s the only difference between minimum kerb weight and kerb weight. Kerb is mostly a UK term that has taken on a broad acceptance. However, it is often spelled “curb” in the United States and a few other countries.
The term is pronounced the same, and both terms mean the same thing. So there is no difference between the curb weight of a vehicle and the kerb weight of a vehicle. They’re both the same term.
How is kerb weight calculated?
Although the kerb weight is a simple statement of how much an empty vehicle weighs, calculating it properly is quite an adventure. It's a complicated process, at least in terms of the running around you would have to do to obtain an accurate measurement.
- Open your vehicle’s manual
- Determine the exact amounts of every fluid (excepting gas) that your vehicle takes
- Top off all of your fluids
- Access a truck stop weight scale
- Empty the vehicle of all accessories, leaving it completely empty
- Ensure that you have either half a tank of gas or a full tank
- Match your vehicle’s weight with what your manual says or the vehicle’s manufacturer
In your vehicle’s manual, you will find all the fluids your vehicle takes and the exact amount it is supposed to hold. Kerb weight includes coolant, transmission fluid, oil, power steering fluid, and brake fluid. If you want a minimum kerb weight, you will have to empty the gas tank completely.
Once you know what all of the fluids are supposed to be at, ensure that you go through each one and top them all off, getting every fluid to the maximum line. Transmission fluid will be the most difficult, as you have to be very careful not to exceed the maximum amount when you can’t visually track how much is going in there.
Oil is a little difficult as well, as you can only add a small amount and keep checking the oil dipstick as you go. The one thing that you cannot determine is the weight of the fluid that is currently sitting in the system. For instance, when you turn the car off, your transmission fluid doesn’t all return to the tank.
The same is true of all of the other fluids. Some of them are resting in the various tubes and pipes throughout your vehicle, and you have no way to measure those unless you use pressure to drain every last one of them out.
Accessing a weight scale
A simple way to do this is to go to a truck stop on the side of the interstate. The only problem is that you can’t get in the way of everyone’s activities while they are weighing trucks passing through.
You will probably have to know someone that works there to pull this off, so you can go whenever the truck stop is closed to trucks coming in. If you know a mechanic, you can probably get your car into the shop and have it weighed on their scales.
Make sure that whatever weight scale you use, your car is completely empty of everything except for what the car came with, like the seats. Even an extra car seat sitting in the back will throw off the kerb weight to the tiniest degree.
Measuring the kerb weight and minimum kerb weight
If you really want to get the absolute minimum kerb weight, you will have to drain the gas tank. You can either siphon it out or run the car until it runs out of gas. If you want the standard kerb weight, you just need to make sure that you have half or a full tank.
A full tank is easiest because you don’t have to keep an eye on the fuel gauge and stop right when the needle approaches the halfway point. Whether you have a half tank or a full tank, it's still considered to be an accurate kerb weight measurement.
Once you get your weight, whether it's minimum kerb weight or regular, you can then match it to the manufacturer’s kerb weight for your vehicle. The odds of it being exactly the same are slim and none. However, you will probably be pretty close.
What are kerb weight and minimum kerb weight used for?
When a brand new car is sitting at the dealership, listing the kerb weight on the new vehicle is the most popular method for dealerships to use to convey the vehicle’s heaviness to potential buyers.
People like to know the weight of things. This is especially true with vehicles, as some may be uncomfortable with heavier vehicles, and others may prefer the heaviest vehicle in the lot. Besides, it's one of the specifications that have to be listed when selling a car anyway.
The best way to convey the weight of a car to a potential new customer is to tell them the exact weight of the car. Unless you are getting a CDL, most people are confused by GVWR, GAWR, GCWR, and all of these various weight measurements that DMVs, state officials, and federal officials like to throw around all of the time.
Kerb weight, once the customer understands the meaning of kerb (curb), is an easily understandable indication of how much the vehicle weighs. Some dealerships provide both the minimum kerb weight and the standard kerb weight because both measurements are as accurate as you can get.
Kerb weight vs gross weight
Gross weight is where things get complicated. That’s because most of your gross weights are hypothetical. For instance, you will see gross weight terms along with words like if, when, or maximum.
Gross Vehicle Weight Rating is a good example because it is the maximum weight that a vehicle can reach before it exceeds its own safety standards. Or, GVWR can mean that a vehicle can weigh up to a certain amount before you are required to have a commercial driver’s license (CDL) to operate it.
Kerb weight keeps things simple while everything else is a bunch of what if questions.
- Kerb weight is the weight of the vehicle completely empty except for a half-full gas tank or a full gas tank
- Gross Weight equals kerb weight + the maximum load capacity
- Gross Vehicle Weight Rating is basically the Gross weight with determining factors involved
- Gross Combined Weight Rating (GCWR) is the maximum towing weight of a vehicle
- Gross Axle Weight Rating (GAWR) is the total amount of weight that can be applied to each axle in the vehicle
All of the weights, except for kerb weight, involve outside factors and measurements that are practical and valuable weight determinations. However, they can also get pretty complicated.
Since the weight ratings are complicated by several outside factors, you won’t often see them when you are shopping for a family vehicle at your local dealership. Of course, if a Chevy dealership wants to market the towing capability of the Chevy Silverado, then you will start seeing gross weight terms plastered all over everything.
Kerb weight is the simplest measurement and the one that is always supplied by the vehicle’s manufacturer. It's usually on that large sticker list plastered to the window when you are car shopping or you will find it in the vehicle’s manual.
Kerb weight is the weight of the car with nothing else in it, except for the fuel in your tank. Minimum kerb weight is the weight of an empty vehicle with an empty gas tank. It's useful knowledge to have on hand when you are in the market for a new vehicle, and you don’t want something too heavy or too light.