Author Topic: Wind deflectors on roof of 4WD  (Read 1056 times)

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Offline brianvicki

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Wind deflectors on roof of 4WD
« on: December 29, 2020, 07:42:40 PM »
What experiences has everyone had using wind deflectors on the roof of their 4WD to improve fuel consumption when towing a caravan

Offline Craig Tomkinson

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Re: Wind deflectors on roof of 4WD
« Reply #1 on: December 30, 2020, 07:37:55 AM »
Hi B&V, Not a wind deflector, but my dad use to go up north of Weipa camping and fishing for 3 to 4 months nearly every year, and we would put his 3,8m tinny up on his canopy of his 1996 Trayback Cruiser, if we had the tinny forward overhanging the windscreen Dad said it would use more fuel and could feel bit of loss of power into a strong head wind, but if we had the tinnys vee noise level with the top of his windscreen it was like it was not there, hope that helps, Craig 
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Offline edz

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Re: Wind deflectors on roof of 4WD
« Reply #2 on: December 30, 2020, 09:31:14 AM »
Yep, the oldman could tell the difference in fuel use, when we had the tinnie on the roof , Wasnt a great deal but it was an improvement ..Maybe an extra mile or two per gallon at best .
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Offline HKB Electronics

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Re: Wind deflectors on roof of 4WD
« Reply #3 on: December 30, 2020, 10:17:35 AM »
Hi B&V, Not a wind deflector, but my dad use to go up north of Weipa camping and fishing for 3 to 4 months nearly every year, and we would put his 3,8m tinny up on his canopy of his 1996 Trayback Cruiser, if we had the tinny forward overhanging the windscreen Dad said it would use more fuel and could feel bit of loss of power into a strong head wind, but if we had the tinnys vee noise level with the top of his windscreen it was like it was not there, hope that helps, Craig

That sounds more a case of moving the boat into the dead spot created by the windscreen, ie the windscreen angles the air stream up over the the dingy, if you move the boat forward then before the windscreen then the air stream comes up under the boat and forms a dam, ie the opposite to a deflector. having a deflector will raise the air flow even more hopefully over the top of a van etc but you still have wind resistance to the deflector but hopefully not as much as hitting the front of the van.
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Offline silverfox1111

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Re: Wind deflectors on roof of 4WD
« Reply #4 on: December 30, 2020, 03:16:30 PM »
This same question came up on a book face pages recently. Most of those that replied said they had a small improvement in fuel economy but the biggest gain was stability of the van, especially when in windy conditions or when in dirty air, such as passing big trucks.
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