remap or chiptuning

Hi, Apologies for probably sounding like an inexperienced newbie, but i can admit that's exactly what i am :fail I have just purchased myself the new 2015 Mercedez Benz E250 CDI Saloon and am looking to purchase and install a chip but many people telling me different things about how it could...

I am thinking of buying an E270 or an E220 CDI and scrolling through the internet (as you do) before I buy, I have come across numerous websites that claim to be able to uprate not only HP (PS) but also Torque (NM) and save fuel. Does sanyone have any real information on whether these chips or...