I have an 11 yr old diesel car and wonder why it is so reliable in the cold weather. she fires up Straight away and never cuts out when waiting at the traffic lights. my neighbours have a petrol car that's only 5 yrs old and they struggle to start theirs in the cold even though it has a new battery and is serviced yearly at the same time as mine. also i see petrol cars cutting out at the traffic lights and mine ploughs on through. why are diesels so much better than petrol?