Weight reduction The ST185 is the heaviest GT-Four made - my Carlos Sainz weighs in at 1450 kg according to the chassis paperwork. Weight kills performance, hence I decided to take unnecessary weight out of my car. Below you find a list of parts and their weight. I'm not saying you can just remove these parts for better performance, but it might help you better understand your car's weight (distribution). Interior   Part Weight (kg) Remarks Carpet, boot 0.880 Cup holder 0.220 Panel, boot - left 1.335 Including interior light unit, excluding strut cover Panel, boot - rear 0.935 Panel, boot - right 1.215 Excluding jack compartment panel and strut cover Panel, jack compartment 0.145 Parcel shelf 2.980 Seatbelts, rear 2.120 Seat brackets, rear 0.860 5 pc. Seats, rear 16.100 Leather, excluding brackets Spare wheel 11.XXX Space saver, steel Spare wheel clamp 0.120 2 pc. Spare wheel cover 0.705 Excluding jack handle Steering wheel 2.185 Strut covers, rear 0.110   Engine bay   Part Weight (kg) Remarks Air box 1.180 Including air filter Air box feed 0.190 Engine bay side only Alternator scoop 0.310 Alternator snorkel 0.750 Including brackets Battery lead (loom) 0.195 Negative terminal Battery lead (loom) 0.245 Positive terminal Battery clamp 0.245 2 pc. Charcoal canister 1.360 Including brackets Coolant pipe, turbo 0.340 Part of stock radiator setup, CS/GrpA Rallye/RC only EGR piping 0.780 Piping and valves Intake piping 0.995 Air box to turbo Related links Stripped interior