Posted on 12/19/2025
Diesel engines are built for hard work, long life, and serious torque, but they are also more sensitive to temperature changes than most gas engines. When the weather turns cooler, small issues with fuel, glow plugs, or batteries show up quickly. A little extra attention in these months can prevent hard starts, rough running, and some very expensive repairs later on. Why Cooler Weather Affects Diesel Engines Differently Diesel fuel ignites from heat created by compression, not a spark plug, so cylinder temperature is everything at startup. When the air and engine block are cold, it takes longer to build enough heat for clean combustion. That is why diesels use glow plugs and high-compression designs to help them light off. Cooler air also thickens diesel fuel and engine oil. Thicker fluids move more slowly through injectors and oil passages on cold ... read more