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What is a rolling road dyno, and what are the benefits? A rolling road dyno is a device that measures horsepower and torque on an engine of a vehicle while it is running. It was designed to replicate how an engine runs on pavement. A rolling road dyno can be used to identify problems with an engine, such as misfires or air leaks, before they become big issues. Some people may wonder why they should bother with this when they could just get their car tuned up every time its acting up. Rolling road dynos are much more precise in identifying the issue with an engine than just telling someone to tune it up.

What is a rolling road dyno?

A rolling road dyno is an apparatus that is mounted on a very large vehicle that has an air compressor installed in it. It is often driven over large surfaces, including a track with a road. An automotive service shop such as Power Lift will purchase a special high-pressure air pump and a turbo charger. The pumps push air through the compressed air hose, while the turbo charger will compress it and transfer the energy to the vehicle. The goal of this setup is to be able to pull power and torque measurements on the vehicle, without the vehicle moving. This is the same type of setup seen in an autocross event. These measurements can be done while the vehicle is driving along a straightaway, or once the vehicle is turning a corner.

Why use it?

Rolling road dynos give the technician a better sense of what is going on with an engine. These devices can measure horsepower and torque at any point, which means they can locate if something is wrong with the engine before it becomes a big problem. If something goes wrong and there is not a way to figure out the problem, the engine can seize up and throw the car into gear. A rolling road dyno can determine what the issue is or provide an idea of what direction it needs to go. For example, if the person is messing with the engine but cannot find anything wrong, this device can be the key to getting to the bottom of the issue. The main advantage to using a rolling road dyno is that it can be a lot more precise in diagnosing the issue with an engine than just looking at the symptoms.

What are the benefits of getting your car tuned on a rolling road dyno?

Rolling road dynos are specifically designed to measure horsepower and torque, unlike a traditional engine dyno. All dynos are able to measure these stats, but not in a precise enough way to determine exactly how much power or torque your engine is making. The rolling road dyno measures horsepower and torque in one scan and gives a more accurate reading than an engine dyno. These devices are also often used for diagnosis purposes on engines and suspension on a vehicle. The reason is that the rolling road dyno can sample more of the engine with each pass and gives a clearer picture of what exactly is going wrong with the engine. Rolling road dynos can provide a great service for both the driver and the vehicle owners.

Rolling Road Dynos Vs. Tuning Up Your Car

Tune-ups are helpful because it tells you what’s causing the problem. Rolling road dynos, on the other hand, are very precise in diagnosing the problem. For example, if the problem is misfires, then you can see how severe the issue is by seeing how much the rotor has been spun. If the problem is air leaks, the misfire problem will show up more because the rotor will spin very quickly as the air leaks out of the exhaust system. Another benefit of a rolling road dyno is that it can also be used for checking an engine’s ignition. This means it’s important to test the ignition at least once a month and have an electrical expert check out the system. Rolling road dynos also help to produce more power. A rolling road dyno measures the torque at each wheel.


This article does a great job of explaining what a rolling road dyno is and why it’s great for each individual situation. In each case, it presents a real-life scenario and tells you what to do. This is a great resource for young engine students.