DickieG wrote:Earlier this week I came up behind an NSU Prinz sat stationary in traffic for a while (and was reminded of how unpleasant the fumes are from an old car) it's quite a while since I've seen one of those NSU bathtubs on the road.
Old cars without cats smell bad because the composition of the current available unleaded petrol is vastly different from the leaded stuff they were designed to run on. I believe the smell originates from the octane boosters used and the much higher nitrogen oxides (NOx) produced due to the hotter combustion of these fuels. In a cat equipped car the cat effectively neutralises these smells. You can tell that by smelling a cat car when it's cold. It stinks to high heaven but once hot there's no smell at all as the cat does it's job. A good basic test to see if the cat is good actually...
Lead didn't used to smell, it just poisoned you slowly...
Years back I always used to use old engine oil as a rust proofer and regularly covered the underside of whatever old heap I was running at the time.
I'm sure the MOT tester would just love you for doing it now
Most likely issue an advisory for oil leaks...