Picked up my C5 yesterday, 08 model VTR+ 1.6 diesel. Any tips? It cruises great, but when you accelerate the mpg goes down the plug hole. Is this just large car, smaller engine? Is a re map worth it? I had a 110 Picasso previously that was riddled with faults and cost a fortune. Had it chipped the difference was nominal and had to get rid before it died, hence the C5.