So what’s the difference between the B58 and the B58 TU1? First of all, the injection system now operates at a pressure of up to 350 bar compared to the previous 200 bar. Increasing the pressure makes a significant contribution in reducing the number of soot particles, and in accordance to the Worldwide Harmonized Light Vehicle Test Procedure, we should look forward to a reduction of “more than 50 percent.”
The injection system is complemented by a one-piece chain drive, which eliminates the base wheel of the previous two-piece layout. The optimized design of the slide rail is another highlight, promising less friction in the chain drive. More to the point, BMW quotes an improvement of 30 percent.
In regard to the cylinder head, the all-new design with an integrated manifold enables the more efficient distribution of heat. The turbocharger has been adapted to the different manifold, with BMW saying that this solution brings a weight saving of two kilograms compared to the B58 from 2015.
Last, but certainly not least, thermal management is further improved by the split-cooling system. What that means is, two cooling circuits work their magic on the cylinder head and crankcase, keeping the engine at optimal operating temperature.
Based on the only diagram released by BMW on the B58 TU1, the engine will be used in models ranging from the Z4 to the 3 Series, 5 Series, 7 Series, 8 Series, and X5. But knowing the Bavarian automaker, the B58 TU1 will - sooner or later - be offered in the 4 Series, 6 Series, X3, X4, X6, and X7.