Most people dont realise the Tempest is a diesel. the only time it is noticeable is on initial pickup in response to the accelerator....just a slight gruffness.....then it goes quiet and smooth. Mind you, this isnt as noticeable since the first service - despite them saying they didnt do anything to it. One of the new owners is claiming much improved mpg - which is what a diesel car this engine size should give but dosent seem to, to most of us. So anybody know what tweaks kia have done to the engine??? ..... and if they have messed with something - can we all get it done???