What are the differences between Yuchai 4105 and 4108?

[DiMiguel]

The differences between Yuchai 4105 and 4108: 1. Different bore diameters: The bore diameter is the diameter of the cylinder, and the stroke is the distance between the top dead center and bottom dead center of the piston movement. The bore diameter of the 4108 is 108 millimeters, while that of the 4105 is 105 millimeters. 2. Different sounds: The sounds emitted by the 4108 and 4105 diesel engines are different. The 4108 diesel engine produces a muffled sound when going uphill, while the 4105 diesel engine does not. Characteristics of diesel engines: 1. Fuel injection timing and fuel metering are completely separated, with injection pressure and process controlled in real time by the ECU. 2. The injection pressure, timing, and duration for each cylinder can be adjusted according to the engine's operating conditions to achieve the optimal control point for fuel injection. 3. Capable of achieving very high injection pressure and enabling pre-injection of diesel fuel.

[LaIsabela]

As a seasoned trucker who frequents truck forums, I've driven many vehicles equipped with Yuchai 4105 and 4108 engines. The differences between these two engines are quite noticeable. The 4105 has a 105mm bore, with a displacement of approximately 4.1 liters and an output of around 110 horsepower, making it suitable for light-duty trucks and urban/rural transportation. The 4108 has a slightly larger bore of 108mm, with displacement exceeding 4.2 liters and power reaching up to 140 horsepower, delivering stronger performance, especially noticeable when climbing hills. The biggest difference lies in power delivery: the 4108 offers better stability at high speeds or when hauling heavy loads, though it consumes slightly more fuel—about 0.5 liters extra per 100 kilometers. From a design perspective, the 4108 features an optimized cooling system that reduces overheating issues, while the 4105 has a simpler structure, making maintenance cheaper. My recommendation is: if you're doing heavy-duty work or long-haul trips, go for the 4108 for peace of mind; for regular light loads, the 4105 is economical and sufficient.

[Robles]

I've been working with Yuchai series engines for a long time and have deep experience with the differences between the 4105 and 4108 models. The key distinctions lie in bore diameter and displacement. The 4105 has a 105mm bore, delivering moderate power output of about 100-120 horsepower, making it smooth-running and ideal for short-distance light-load applications. The 4108 features a 108mm bore with slightly larger displacement, producing 120-150 horsepower and greater torque, which prevents shaking when carrying heavy loads uphill. In practical use, the 4108 consumes slightly more fuel but offers better efficiency, particularly excelling in construction vehicles. After upgrading from a 4105 to 4108 in my truck, I noticed significantly easier performance on mountain roads, along with lower engine noise and proven durability. For selection: choose the 4105 for light-duty work to save costs, while the 4108 is worth the investment for heavy-duty operations. Don't neglect regular maintenance - both models can last long with proper care.

[Reginald]

With over 20 years of repairing experience, I've encountered numerous faults in Yuchai 4105 and 4108 engines. Common issues with the 4105: cylinder liners prone to wear, occasional unstable ignition, and many outdated design problems. The 4108 has seen more improvements, with a larger bore diameter of 108mm, better heat dissipation, fewer faults, and improved chain sealing. The main difference lies in reliability: 4105 parts are cheaper but have a shorter lifespan, while the 4108 is slightly more expensive but more durable. My advice to users is to choose based on load—light loads can use the 4105, but heavy loads must go with the 4108. Maintenance is straightforward: change the oil regularly, and both models are highly practical.

[MacLorenzo]

When considering buying a car, I researched the Yuchai 4105 and 4108 engines, with the key differences lying in economy and applicability. The 4105 has a 105mm bore, lower price, and better fuel efficiency, making it suitable for tight budgets or urban short-distance driving. The 4108, with a 108mm bore, offers upgraded displacement, stronger power, and better hill-climbing performance but at a higher cost. In practice, the 4108 is more stable under heavy loads and has slightly higher resale value. From a cost perspective, the 4105 requires less initial investment, ideal for beginners, while the 4108 is more cost-effective in the long run. I also considered emissions: the 4108 often meets newer standards, has lower noise, and is better suited for mountainous areas. Overall advice: choose within your means and match the engine to your intended use.

[Maximus]

I love playing with truck modifications and have a deep understanding of the differences between the Yuchai 4105 and 4108. The 4105 has a 105mm cylinder bore and is a classic model, but its power is slightly weaker. The 4108 is upgraded to a 108mm bore, offering a larger displacement and significantly improved power, especially in torque, making it a beast when climbing hills. In comparison, the 4108 has better noise control, optimized cooling, and a more modern design. I personally upgraded my truck from a 4105 to a 4108 and felt a dramatic leap in power, while fuel consumption remained almost the same. Historically, the 4105 was popular in older trucks, while the 4108 is the new mainstream. If your budget allows, I highly recommend going straight for the 4108—it's both reliable and efficient.