Minivan Aerodynamics

What is the best position for fuel economy of the cross bars on the luggage rack? I’m dealing with a 2006 Buick minivan. I’m guessing tak the far rear of the rack is best, but I’m not sure.

Put the luggage inside the van.

I think it is best to put it forward to reduce drag at the rear. The position from front to rear probably doesn’t matter as much as the height. Try to put everything as low as possible and spread it out.

Strapping the luggage down and then putting a tarp over it in a shape resembling the hood and windshield area of the van would probably be best. This question is really driving me crazy! I think my last answer is best.

Luke, you could do your own aerodynamic study. Use a scale model of the mini-van and fashion some items to go on the top. Use a clear plastic tube, a smoke machine, and a fan. Set it up to blow smoke over the model with the “cargo” arranged in different ways. Using the smoke, you’ll be able to see the effects of various setups.

If you load up so much stuff and passengers too, I guess you would need the luggage rack. Without luggage, you might want them up front because I never heard of a minivan with such acceleration that the bars just got blown off the vehicle. If you put them far back, make sure they’re tight. If I put it that way, it seems to make sense for about six seconds. You can’t choose what runs into you or you run into that could knock the bars off the rack and it probably doesn’t matter if it hits hard. I am trying to avoid the question you asked without saying I don’t know. You have the time to experiment. Maybe your owner’s manual will say something like moving them now and then will keep them from sticking in place. There could be the desired low pressure zone toward the rear. The most pressure is just behind the windshield so I guess to the back. Good luck and please don’t stay awake thinking about it. One of us is enough.

Dear RobbKZrider,
I have ridden in a minivan, And I know 6 people can fit comfortably with room in the back for luggage.7 can fit and still have room for a spartan amount of stuff. Maybe you should trade in your minivan for a school bus. School buses are nice, and if you take out some of the seats you could start you’re own furniture moving business on evenings and weekends.

I would not worry.

There is no one answer unless you have a wind tunnel handy. Since every vehicle varies the flow of air will too. There is no generic answer for this.

Given your just worried about cross bars I would position them on the least amount of noise which will make you and passengers happier campers.

I’m with you, Andrew. Minimize noise for passenger and driver comfort. That may also minimize drag, too. The correct position to accomplish this was noted in the owner’s manual of the Chrysler products I’ve owned that came with luggage bars; perhaps Buick also includes this info.

hahahahahaha

The difference in mileage, if there is any, is unlikely to be distinguishable without sophisticated testing. However, placing the weight more toward the center of the vehicle will keep your weight distribution closer to that which the car’s chassis is designed around. Your handling will be more consistant with or without the load, and that just may be the best way to go.

Everyone is assuming you have luggage on the rack. Is this so?

I’m asking because you never mentioned a load, just the crossbars.

Awhile ago there was a poster who asked the same question, but was referring to the rack only. In which case is irrelevant.

How you position the load has to do with weight distribution on the axles (more than efficient air movement) and the maximum capacity of the rack itself.

You do not want to overload or load to make the vehicle top heavy.

All I’m saying is Drive Safely.