If you’re in the market for a van type semi trailer, whether to transport perishables, retail goods, or industrial supplies, fuel consumption is likely top of mind. As a semi trailer supplier with 12 years on the road, I’ve seen too many operators get stuck with vague estimates that blow up their operational costs within a few months. A lot of customers come to me thinking “a semi is a semi” when it comes to fuel, but van type trailers have unique quirks that make accurate measurement non-negotiable. Skip the guesswork—here’s how we measure it properly for our own trailers, and what you should look for when vetting any van type semi trailer’s fuel efficiency. Van Type Semi Trailer
First, let’s get clear on what “accurate” even means in this context. A lot of drivers or operators will jot down a fill-up date and miles driven between stops, but that’s not accurate. Fuel consumption for a van type semi isn’t just distance divided by fuel; it’s also tied to the trailer’s own weight, aerodynamics, cargo type, and even how you couple it to the tractor. Over the years, our team has tested three core methods, and we only recommend the most rigorous one for customers who need real, usable data for their fleet. Let’s break them down: the basic method, the intermediate, and the professional lab test we use for every trailer that leaves our yard.
The basic method is the one most people rely on, and it’s the first red flag for error. It works like this: log your odometer reading right before you pull into a fuel station, fill the tank completely until the auto-shutoff clicks, write down how many gallons you put in, then drive to your next stop, fill up again, and divide miles driven by gallons to get MPG. The problem here is that almost no one gets a “complete” fill every time. If you’re in a hurry, you might fill until the pump cuts off once, but when you’re measuring fuel, even a half-gallon difference over 10 stops adds up to 5 gallons a month. For a semi that gets 6.5 MPG, that’s a 1% error rate, which might seem small until you’re running 10 trailers: that’s 50 gallons a month, or $150 extra, per trailer. Multiply that by 50 trailers in a fleet, and you’re talking $7,500 a year in wasted money. Also, odometers on both tractors and trailers are often off by 2-5%, depending on tire wear and calibration. So while the basic method works for rough estimates, it’s useless for accurate measurement.
Next is the intermediate method, which fixes most of the basic method’s flaws, but still has gaps. For this, you use the tractor’s built-in telematics, not just manual fill-ups, and you account for the trailer’s contribution. Our team at the supplier level does this during pre-delivery inspections for customers who ask. The key here is separating tractor fuel use from trailer use, because that’s where van type semis differ from other trailer types. A flatbed trailer’s aerodynamics are different, a reefer has its own engine, but a standard van type semi works in tandem with the tractor. To do this, you log the tractor’s fuel consumption from telematics over a route where you run without a trailer first. That gives you the tractor’s baseline fuel use: let’s say, when empty, the tractor uses 0.5 gallons per mile on a flat highway. Then, when you couple the van type semi, you run the same exact route, same speed, same load (or close to it), and subtract the baseline from the total fuel used to get the trailer’s fuel contribution. This method gets you within 2-3% accuracy, which is pretty good for day-to-day operations. But even here, there’s a variable we can’t account for on a single test run: cargo type. If you’re hauling heavy pallets of electronics versus light, bulky clothing, the van’s aerodynamics change a lot. Bulky cargo fills the entire van, creating more drag than a half-full van, which increases fuel use by 4-6%. That’s why the intermediate method needs to be run multiple times with different cargo weights and sizes to get a true average.
Now, the method we swear by, and the one we provide to every customer who wants hard data: controlled, repeatable testing under standardized conditions. This is the gold standard, and it’s what we use to verify the efficiency ratings on our van type semi trailers before delivery. Here’s how it works, step by step. First, you lock in variables so they don’t skew results. That means same tractor (we use our own test tractors, calibrated with fresh tires and correct inflation, since underinflated tires can add 5-7% to fuel use), same route, same driver, same speed, same weather, and same cargo. We pick a route that’s 100 miles of flat interstate, no hills, no city stop-and-go, because hills and stop-and-go can add 10-15% to fuel use, depending on how aggressive the driving is. We run the test three times to account for small variables, like wind speed or minor tire wear.
For the van type semi specifically, we also test two critical components that most suppliers skip: the trailer’s aerodynamics and its curb weight. A lot of customers don’t realize that a van type trailer’s fuel efficiency is 20-25% determined by the trailer, not the tractor. Aerodynamics: if you’re buying an old van type trailer that has square edges on the back, no side skirts, no undertray fairings, that’s a lot of drag. Our new van type trailers come with factory-installed side skirts and rear diffusers, which reduce drag by 8%, translating to 0.5 MPG gain. Curb weight is another big one. A lighter van type trailer means you can haul more cargo without hitting weight limits, but also, the trailer itself uses less fuel because it’s not pulling extra weight. Our standard van type semi trailers have a curb weight of 12,800 pounds, which is 1,500 pounds lighter than many competitor models. That 1,500 pounds translates to about 0.3 MPG difference. For a fleet that runs 100,000 miles a year per trailer, that’s 3,000 gallons saved a year, or $9,000 at current diesel prices.
Wait, but you might be asking: how do you separate trailer fuel use from tractor use in this controlled test? We use a precision fuel flow meter, not just the tractor’s telematics, because tractor telematics can be off by up to 10% depending on the model. The fuel flow meter is installed in the tractor’s fuel line, so it measures every drop of fuel going to the engine, no guesswork. Then, we run the test with the trailer coupled, and compare it to the baseline test run with no trailer. The difference is exactly the fuel the trailer is adding. For our van type semis, we’ve found that at 65 mph, the trailer adds about 0.8 gallons per 10 miles, while a competitor’s older model adds 1.1 gallons per 10 miles. That’s the kind of hard number you can use to compare trailers, not just vague claims of “better fuel efficiency.”
Now, let’s talk about common mistakes people make when measuring their van type semi’s fuel consumption, because even with the right method, small errors can creep in. First, don’t forget to account for reefer units if your van is a refrigerated model. A lot of van type semis are used for perishables, and the reefer engine burns fuel independently. If you’re measuring total fuel use without separating the reefer’s fuel, you’ll end up with a number that’s 15-20% higher than it should be, and you’ll think the trailer is less efficient than it is. We see this all the time with grocery delivery fleets, and it’s an easy fix: add a separate fuel log for the reefer, or use a dual-fuel flow meter that tracks both the tractor and reefer.
Second, don’t test fuel efficiency only at highway speeds. A lot of drivers cruise at 70 mph on the interstate, but most urban routes are 55 mph, with stop-and-go. Van type trailers are most efficient at 55-60 mph; above that, aerodynamic drag increases exponentially. We’ve tested that at 75 mph, our van type trailer uses 12% more fuel than at 60 mph. So if you measure fuel use only at 75 mph, you’ll get a worse number than your actual daily use, and you might make bad decisions about your fleet. Always test at the speed you actually drive, because that’s the number that matters for your budget.
Third, keep track of tire maintenance. This is a simple one, but it’s often overlooked. Underinflated tires on either the tractor or the trailer add rolling resistance, which increases fuel use by 3-5% per 10 psi of underinflation. We include a tire pressure monitoring system with every van type semi we sell, and we recommend checking tire pressure before every long route, because even a 10-degree temperature change can lower tire pressure by 1 psi. If you skip this, your fuel consumption measurement will be off, and you won’t know why.
As a semi trailer supplier, our job isn’t just to sell trailers—it’s to make sure our customers can run their fleets efficiently. That’s why we include a detailed fuel efficiency report with every van type semi we deliver, based on that controlled testing I mentioned earlier. The report includes numbers for different speeds, different cargo weights, and even recommendations for small changes you can make to save fuel, like adjusting your speed or adding aerodynamic accessories if you’re running older trailers.
I’ve had customers come to us before, saying their fuel costs are 10% higher than they expected, and after looking at their measurement method, we realized they were using the basic fill-up method, which was overestimating fuel use. Once they switched to the controlled test, their numbers matched our reports, and they saved thousands a year. That’s the value of accurate measurement: it’s not just a number on a spreadsheet, it’s real money in your pocket.
If you’re in the market for a van type semi trailer, or if you’re unhappy with the fuel efficiency of your current trailers, don’t rely on vague estimates from your driver or a salesperson’s generic claims. Ask for the test data, and ask about how to measure your own fuel consumption accurately. We’re here to walk you through every step, from understanding the test results to choosing the right van type semi for your specific cargo and routes. Whether you run a small fleet of 5 trailers or a large operation of 500, we can help you get the accurate data you need to keep your costs down and your fleet running smoothly.
Tank Transport Semi-trailer References
- American Trucking Associations. “Fuel Efficiency Best Practices for Heavy-Duty Trucks and Trailers.” 2022.
- National Highway Traffic Safety Administration. “Aerodynamic Drag Reduction for Commercial Heavy Vehicles.” 2021.
- Society of Automotive Engineers. “Test Methods for Measuring Fuel Consumption of Combination Vehicles.” SAE International J1321, 2020.
- Truckload Carriers Association. “Fleet Fuel Management Guide: Measuring and Reducing Fuel Costs.” 2023.
Shandong Tengyun Special Vehicle Manufacturing Co., Ltd.
Shandong Tengyun Special Vehicle Manufacturing Co., Ltd. is well-known as one of the leading van type semi trailer manufacturers and suppliers in China. Please feel free to buy high quality van type semi trailer made in China here from our factory. For price consultation, contact us.
Address: Middle Section of Dongfeng Road, Liangshan Street Office, Liangshan County, Jining City, Shandong Province
E-mail: 15634517777@163.com
WebSite: https://www.tengyuntruck.com/
