It’s a Volvo D5 engine with 185 hp, 5 cylinder diesel. The car consumes oil with good warm-up of the engine. At short distance or 50km of land, no oil usage. At low engine load and below 100°C engine oil temperature no oil consumption. I have a cheap OBD2 plug to read out cooling water and oil temperature. I suppose, with good warm-up, the barrel bushes stretch so much that the piston rings do not I have two ideas to reduce oil consumption. 1. Exchange charge air coolers. This lowers the heat input into the engine through cooler charging air. If necessary, it also runs more efficiently and needs less diesel. The charge air cooler has many, many lamellas folded by insect impact. There is hardly any lamella straight. 2. Rinse cooling system. With the lowest point in the cooling system, the oil cooler sits. This is a block at the oil tank where cooling water is the oil If there are deposits in it, then the heat transfer to the water is worse. The engine runs a little warmer. Basically: I drove in the summer morning from 5:00 360km highway. All load levels. 120, 140, 160, 180 to 220 km/h. -No oil consumption. No difference on the tarmac. Air on the asphalt still cool. Then in the afternoon on the asphalt with 100kg more charge back. About cruise with 140/km. After 160km ~0,9L oil consumption. The air was very warm on the asphalt. Because of summer sun. Then different full-gas rides at night on the highway. 320km distance to the findings. Calculating about 1.5L oil consumption at 1,000km. Engine oil at 120°C and higher. Then I recently drove the 320km motorway with cruise control and 120km/h. the engine oil remains below 100°C. -No oil consumption. Next time I will drive the 320km so that I have 110°C motor oil. Let’s see if he then takes oil.