What does HTHS mean?

[StephanieRose]

HTHS stands for "High Temperature High Shear viscosity," which is an indicator of the viscosity stability of engine oil under high temperature and high shear conditions, reflecting the oil's ability to maintain lubrication under such conditions. Here is some relevant information: Relationship between oil viscosity and anti-wear properties: From an anti-wear perspective, it's not just the oil film that plays a role, but more importantly, the additive formulation of the oil. The anti-wear additive system is crucial because wear occurs under the most extreme boundary friction conditions during operation, where the oil film between friction pairs no longer exists and cannot provide anti-wear protection. Additional chemical components, such as zinc, molybdenum, and phosphorus, are needed to provide anti-wear effects. HTHS value and the engine: When the engine reaches normal operating temperature, wear occurs under extreme boundary friction conditions. At this point, the oil film between friction pairs is extremely thin, requiring both oil film strength and anti-wear additives to provide protection. Whether during the compression stroke or the power stroke, the piston experiences the highest pressure near the top dead center. Due to the circular motion of the crankshaft, the connecting rod is mostly in an inclined position, increasing the pressure on a single side of the piston. This results in extremely high shear pressure from the piston ring against the cylinder wall. Combined with high-speed shear motion, severe boundary friction occurs. If the oil film strength is insufficient and breaks, accelerated wear is inevitable. This wear can lead to reduced sealing within the cylinder, allowing oil to enter the combustion chamber and burn. Deterioration and damage: If the tire pressure exceeds the standard by too much, it can cause excessive outward expansion of the tire, weakening its strength and reducing its lifespan. Before inflating, clean any dirt from the valve stem and ensure the valve core is not loose. After inflation, check for leaks and secure the valve cap to prevent dirt from entering the tire. Tire pressure can be measured using a tire pressure gauge. Measurements taken at room temperature are more accurate, while those taken at very high or low temperatures are less reliable.

[VanessaLee]

I guess you might be asking about HTHS, which is a key indicator in motor oil specifications, representing High-Temperature High-Shear viscosity. Simply put, it tests the oil's ability to maintain a protective layer under high-temperature and high-speed engine operation. If the HTHS value is too low, the oil film can easily break, leading to increased engine wear and reduced lifespan. In my personal experience, I pay special attention to this value when choosing oil. For example, oils with ACEA A3/B4 certification typically have an HTHS above 3.5mPa·s, ensuring engine stability during long-distance driving or traffic jams. Relatedly, oil viscosity grades like 5W-40 are also affected by HTHS. I recommend regularly checking the maintenance manual and avoiding cheap, low-quality oil to save money—safety is the top priority. Specifically, you can look for the numbers on the oil label or consult a repair shop to match your vehicle's needs.

[DeFelix]

From the perspective of daily driving, HTHS refers to the High Temperature High Shear index, which is crucial for engine health. I remember often driving on highways where engine temperatures run high - a good HTHS value keeps the oil more viscous, preventing direct metal-to-metal contact. For older vehicles or performance models, paying attention to HTHS becomes even more critical as poor heat dissipation can lead to issues. Regarding oil selection discussions, it can be as simple as checking the high-temperature shear value printed on the packaging - generally, values above 3.2 are considered good. With this in mind, I always remind friends to use certified oil products during oil changes and avoid opting for cheaper, lower-standard oils. The actual impacts include changes in fuel consumption or increased noise levels, while maintaining smooth engine operation in the long run.

[Arabella]

If you're a new car owner, HTHS stands for High Temperature High Shear viscosity, which relates to the performance of engine oil under extreme conditions. When I first started learning, I found this metric helpful in understanding engine protection mechanisms. Basically, the higher the value, the better, as it can reduce the probability of engine failure. It's recommended to prioritize high HTHS engine oil to avoid short-term oil burning or wear, combined with regular maintenance to keep your car in good condition.