Got a big wide roofbox for the zafira

car has 3 fixing points

I can fit the box toward the front or rear

Ive read conflicting comments on tinternet as to which would be the most ‘aero’

cheers

my guess it would make bugger all difference. I would use the front ones which I think would keep the weight more in the centre of the car rather than over the rear wheels (If you’re using a rood box the boot may be full so there is already weight there). Clearly you have big heavy engine in the front so maybe my thinking is rubbish!

making a zafira more aero is a bit pointless really 🙂

Whichever (if it makes any difference) gives you the easiest access would be my choice.

If there was no difference, I’d probably use the front ones.

I would use the ones than ensure the box is placed so that the front sloping edge is an exact continuation of your windscreen angle for maximum benefit.

Closer to the back so you can get your belongings out when it sets itself on fire?

whichever is quieter, likely the rear

I was in Calais on Monday afternoon heading back after my second week in t’alps this year when i saw a car with a strange storage arrangement.

a Thule towbar mounted rack on the back with what looked like a roofbox sitting sideways on aforementioned rack.

I have no idea if this is a standard arrangement or some kind of Heath Robinson bodge but it looked weird and made me do a big double-take.

I think you have answered your own question re making a Zafira more aero but perhaps experiment on a couple of longish drives using your cars MPG function?

A mate found that rear rack mounted bikes were most aerodynamic on a golf when he had the sunroof tilted up at the rear to deflect the air over them.

Front I would say to keep the car more balanced. Safety more important than 0.5 mpg.

Make sure you can get the boot lid up…

I put mine on too far back once, loaded it up with camping gear, couldn’t get the boot open more than about 30cm.

Had to load the car through the back seats. It was a colossal ball ache…

was in Calais on Monday afternoon heading back after my second week in t’alps this year when i saw a car with a strange storage arrangement.

a Thule towbar mounted rack on the back with what looked like a roofbox sitting sideways on aforementioned rack.

Thule BackUp innit!

We had a toolbox on our old Octavia. Purely by accident it ended up towards the back of the roof, although the bulk of the weight was in front of the rear axle. It positioned the front of the roof box behind where the wind would come up off the windscreen and seemed to create no more drag/loss of fuel economy than without the box on.