These Brake Discs will fit the following: Range Rover Sport 06-09 with 4.2L Supercharged Engine, 3.6 TDV8 and any vehicles with Brembo Calipers on the Front. Range Rover Sport 2009 Onwards all Vehicles apart from SUPERCHARGED 5.0L Petrol. Discovery 3 with 4.4L Petrol engine. Discovery 4 with 5.0L Petrol and 3.0 Diesel Engine - Terrafirma brake discs offer increased bite from cold and excellent fade resistance in most 4WD braking applications. Whether itﾒs a steep rocky descent, ploughing through mud and water or just daily driving these brake discs will give excellent stopping performance in all conditions.Grooves are machined into the brake disc to force away the dust and gasses that build up between the pad and disc, keeping the brakes cooler and reducing fade. The cross drillings contribute to cooling and heat dissipation and also allow the gasses to escape. Of course they fill with mud when off road, clean them out afterwards when washing the vehicle to maintain performance and pad life. With the angled grooves it is found that they self clean in most cases. Quality machining to high tolerances using the correct materials ensure Terrafirma brake discs will withstand any test. With overweight four-wheel drive vehicles with oversize tyres itﾒs important to find a set of brake pads that really do perform. A heavily laden expedition vehicle will quickly overheat brakes, very large tyres fitted to off road vehicles also require extra brake pedal pressure to stop them turning. To get the best from Terrafirma Cross Drilled and Grooved (CDG) brake discs we recommend the use of high quality brake pads. These pads give good bite from cold, work well off road especially in low range with high torque engines and transmissions driving against the brakes. They have high wear resistance, low noise and above all when combined with Terrafirma CDG brake discs give a much improved braking performance. For Terrafirma brake discs part numbers it is possible tosimply apply CDG suffix to the original part numbers.