Went out with a friend last night – she’s leaving the country today, sadly – and I noticed, this morning, that my sputum was a black as pitch. (Note: This, Fi, isn’t your fault, or the fault of the car – it’s just a fact of life for those of us with COPD.)
This, which I haven’t seen for years (not since I was a biker), is highly indicative of atmospheric pollution, and I’m sure the fact that we were in a hard-top convertible with the top down, for much of the time, thus bypassing the ventilation system’s particulate filter, is responsible.
So why am I telling you this? Well, if you have severe respiratory problems (or less severe that you’d like to keep that way), and are in the market for a new car, my advice, no matter how pleasant driving with the top down on a summer’s evening, with an attractive woman by your side, might be, then a convertible is probably not for you. In the short term, it won’t harm you, but over the life of the car, it conceivably could. For that reason, getting one with the maximum ventilation filtration is essential – particulates in your lungs, whether from diesels or pollen, are deeply undesirable.
The same applies, of course, to driving with the windows down and/or the sun-roof open, though to a lesser degree due to the differences in air flow – I used to drive with the sun-roof open and the ventilation system running, weather permitting – this allowed the air entering to be filtered, and extracted via the roof. You could leave the air-con running, which will also maximise filtration, but in many cars this jacks up the fuel consumption to absurd levels (in 1999 my Ford Ka3 returned 12mpg with the air-con running – I sent it back!)