DLO ratios (more on proportions)

Yet another Twitter conversation has turned into something I should post here. It feels like I waste a lot of time on Twitter, but to be honest I very much enjoy the debate that it stirs up. I completely agree with the complaints around being able to SEE OUT of any modern car. Designers obsession with low narrow window heights and dynamic rising DLOs, means that modern cars can be a real problem to see out of. For children using the rear seats this becomes even worse and most kids have no view onto the outside world while travelling. Motion sickness can result- although technically NO visibility at all can apparently be better for that issue. So I was busy playing with showing ratios in photoshop. A new Citroen C3 Aircross began the debate, as it has very large ratio of metal to glass. Others named cars they presumed to have huge areas of glass- but analysis shows that even these stick to similar proportions to any sportscar. The preferred ratio is to keep the DLO ratio (Day Light Opening) below 50% for the glass, meaning the ratio of glass to metal (of the door to sill area) should be less than 50% glass and more than 50% metal. For example the worst offender in recent years was the Fiat Multipla. Our favourite example of great “bad” design. The glass/metal ratio is 50/50 and even heading into 55/45 towards the front side-windows perhaps. A Twitter users own Porsche was mentioned as an example of a car with lots of glass- but here we can also see it has the magic formula for DLO/metal ratio. This low ratio of glass was dynamic in the days of the Porsche 924 (compared to ordinary cars), but now just about every vehicle uses this dynamic (metal biased) ratio to help us all imagine we are driving a Porsche… not an ordinary car!