Thread: Wheel on Bonnet = Aerodynamic improvement

Hi,

Thought you may find this interesting, well tha attached doc on the defender aerodynamics.

Cheers

The Entertainer

Threads merged.

Thank you most interesting ! I have always beleived that towing a trailer empty or loaded was a more economical way of moving stuff. Generally on longer runs 1k miles I find it only increases fuel burn by around 1.5 litres per 100Km's. However I do understand trailers are not practical in all circumstances.

Rhino Bars on my Disco is about 1.5-2L/100km worse off. Put them on for a while as I was carrying pipes and other stuff for renovations. After renovations left them on and after a while ( A few fills of the tank) I noticed that I was getting less out of a tank of Diesel than before. Took the Rhino Bars off and fuel ecenomy back to normal.

Cheers
Luke

I too have rhino bars. I was thinking of fabricating up a wind deflector that follows the roofline and lifts the wind over the bars. I have three bars and at the rear I was going to put a canvas bag on a platform when travelling. I was also thinking about designing a wing to push the air over said bag. Was thinking alloy for the wings. To get the shape of the roof I was going to use plastic conduit held in a wooden frame and then transfer this shape to the alloy to get the correct roofline. They quite often use conduit to get nice curves in home made boat building so I thought It would work in this application too.

Now if I can just finish of the fence, the veggie garden, put in a new back lawn, build a chook pen blah blah blah..... I'll have some time to make them!

So am I better off having a road tread tyre or an off road tread tyre on the bonnet?
Will the blocks on the off road tyre create vortices that will affect consumption?

Originally Posted by pannawonica

Thank you most interesting ! I have always beleived that towing a trailer empty or loaded was a more economical way of moving stuff. Generally on longer runs 1k miles I find it only increases fuel burn by around 1.5 litres per 100Km's. However I do understand trailers are not practical in all circumstances.

Here in NZ the legal towing speed is 90km/h and without 100km/h. I can tow an empty trailer at 90km/h and get exactly the same 10km/l as I get on the same trip with no trailer.

This experiment happened because I drove 500km with a trailer to get something that didn't arrive. So I drove 500km home again with the trailer in tow. I had to make the trip anyway, the trailer was the extra bit.

My best estimates of bikes on a bike-rack on the back is 1 litre/100km extra, bikes on a roofrack 2 litres/100km.

Originally Posted by jerryd

Maybe that's why mine is so thirsty

Put the hen on the front and shackle 2 roosters back near the windscreen - should fly up the hills then