Truckers estimate that the average maximum mileage for a well-maintained semi-truck is about 750,000 miles before you have to overhaul or replace it. Yet, while mileage is an important statistic to keep track of, engine hours may be even more important for determining a semi’s longevity. Similar to a boat’s engine hours, people use certain thresholds to determine whether a semi-truck has a low, moderate, or high amount of engine hours on it. If it has under 10,000 engine hours, that’s considered a truck with a low number of hours, while the 20,000 to 30,000 hour range is considered to be high. And once you cross the 30,000-hour mark, that engine overhaul or replacement is right around the corner.
With this metric, you’re keeping track of how many hours the engine is actually running, whether driving or idling. Semi-trucks and many other larger vehicles like it can spend an awfully long time running without moving. This could be the truck running while making an extensive delivery, for sleeping purposes, being stuck in traffic, or some other job-related reasons. Even though the semi-truck isn’t moving, this idling still puts a strain on the engine, and just tracking the mileage doesn’t factor this time into the wear and tear of the truck in the slightest.
In fact, the vehicle driving puts less strain on the engine because its operating as efficiently as it should. That said, while an engine with a lot of hours may not mean you need to replace the whole semi-truck, it does indicate that an engine rebuild or replacement may be necessary, which can cost anywhere from $20,000 to $50,000, on average.
How many engine hours can a semi-truck last?
The raw number of hours isn’t the only thing you need to know, though. It’s also good to know what percentage of the engine’s use was spent idling. This is important information not just for purchasing a semi-truck, but making sure you’re maintaining the one you own as best you can. All you have to do is take the number of idle hours you have and divide it by the total number of engine hours. If your idle percentage is below 20%, you’re doing a good job of keeping it low. If it’s above 35%, that’s getting to be quite high.
If it’s over 50%, however, you may be looking at some serious problems, and it’s not just because you’re wasting fuel by burning an average of 1.5 gallons of it per hour while idling. More importantly, it shows you’re putting excessive stress on the engine and probably shortening its lifespan. In the end. while engine hours and mileage are key factors in determining the health of your semi-truck, it’s also vital to regularly check everything about the vehicle to keep it in the best shape possible.