Roofbox changes towing sensation
 

Morning all.

An observation I felt was worth sharing.

I've been towing caravans for some while now but never with a roofbox.

I've just travelled the 300+ miles to Cornwall with our XC70 & 1500kg van with roofboox on the car.

The roof box is aerodynamically shaped Thule made Volvo brand box and the bars Volvo aero wing.

The difference I found was that the caravan was felt less ie no occasional tugs as headwinds changed with wind direction or passing vehicles.

The roofbox clearly acted as a aerofoil. The vehicle fuel consumption stayed the same, 28mpg and SWMBO got to bring even more things than necessary with her.

that has to be THE best reason to get a roof box,,, :D

years ago i did see a few "wings"

https://www.rvpartsexpress.com.au/me...f/dflector.jpg

always thought "meh" to them as height/angle/distance to-from van + height of van = a shed load of variables to get them to work more as a deflector than air brake

Id forgotten the roof spoiler wings - always amused me to see them still on a car weeks or months after the dummer hols. Just like roofboxes stay on untill November.

And like the stuck-on headlamp converters when back in the UK....

I quite like the F1 spoiler look and with regards roofboxes I know what you mean but houses are getting smaller and sometimes storage is at a premium. You should see how I manage to stow mine at the back of the garage.

Ps if you're hijacking this thread have a word with your spell checker will yer, its struggling with really simple words.:tounge_smile:

I suppose it's obvious when you think about it, I noticed a difference between towing the van with the xc70 and the discovery, but that's more to do with volvo power compared to landrover torque than aerodynamics.
Certainly 60 mpg into a headwind and even the volvo tells you its working by the amount of fuel it uses, still less than the landrover at 40 mind.

In effect you are towing a wall, any ramp must improve matters as airflow is smoothed but modern cars are designed in wind tunnels to optomise airflow, chuck a wall behind them and all the calculations are void.

Paul.