Do you worry about the cost of fuel? I drive a Honda Civic with a diesel engine that gives me about 45mpg - not bad - but not brilliant. Recently, when driving up the M6 I had a little extra time so I decided to stick to 60mph and see how the consumption improved. I was pleased to see the average mpg went up to around 55 mpg. Good! I then noticed that if I drove at a safe but reasonably close distance to a large truck the consumption improved quite dramatically. In fact over a 200 mile journey I averaged 67mpg! That saved me a few bob!
Of course the saving was not unexpected. I know that the vehicle in front will "punch" a hole in the air minimising the drag. What was surprising was the significant difference it made.
Having pondered this for a few days I ran a SOLIDWORKS Flow study to see the effect. In 2013 there are some great comparison tools that allow a side-by-side evaluation. Here are the visual comparisons and a table showing me that the drag force drops from 677N to 105N when in the wake of a truck - that is a whole lot of fuel saving!
However, be careful - keep your distance!
Solid Solutions Management Ltd