BMW 435d xdrive Gran Coupe, one of the most powerful diesel cars among other brands. According to the carwow.co.uk it takes the second place in the fastest diesel pantheon. Adding two more faster diesels: BMW M550d (4.7s) and Porsche Panamera 4S Diesel Sport Turismo (971) (4.5 s) it takes the honorable 4th place. 230 kW engine power and 630 Nm torque lets this diesel reach 100 km/h in 4.8s, according to manufacturer. There are some sources that claim this BMW has only 210 kW of engine power according to dyno tests. And automobile-catalog car testing program ProfessCars states that this diesel reaches 100 only in 5.1 s. Anyway it is the fastest model in F36 class.
Some BMW lovers and BMW forums and tune shops states that some minor changes could be done to his BMW and it will become a BMW M4 killer. Lithuanian tuners startlinesay that just with stage 1 the engine could be optimized to 260 kW engine power. Carthrottle.com says that just with stage 1 they can reach this car to sprint 100km/h in 4.1s, same as BMW M4 (also 4.1s). Bimmerpost forums give more specific description what has to be done to become a M4 killer and reach the sprint to 100 km/h just in 3.7 s.
Lithuanians Startline.lt are more skeptical but they give more complex solution how to improve the power of this bimmer. Adding downpipe, modified larger turbo, M550D injectors, sport exhaust and larger intercooler, could make this car with 333 kW engine power. Sprint to 100 km/h after the tune could be checked with Draggy device. The main issue is that manufacturer claims that this models gearbox is limited to 700 Nm of power. So it could be risky to push it more than that limit. But in bimmer forums some claim they have gearboxes tuned up to 850 Nm and had no problems yet. The project cost could be around 3000 euros. And after that you have a real beast with reasonable fuel consumption. Manufacturer claims that city mode consumes 35 mpg, but real consumption is around 26 mpg and if pushing this car to the limit it won't consume more than 20 mpg. So it is quite reasonable to have this diesel animal in your garage.