spare tire in front of grill on a truck??

[flying kurmaster]

I was wondering if anyone thought this would have any benefits, it would serve as a partial grill block especially if there was nice cover over it, and secondly it would extend out in front of vehicle creating a sliciing through the air effect, a bit like the shape of modern trucks protruding down and forward, minus the nice smooth lines of course. has anyone experimented with this, or do you think it would just foul the air and create more drag, what say you ???

[Frank Lee]

My camper truck has that and I'm sure it hurts aero. But that thing is a worse aero disaster than a barn. It disrupts whatever nice flow there may be across the hood.

[flying kurmaster]

if you made a cone shape cover, something like the old studebakers, I wonder if that would help. It sure is a handy place to put a spare tire, would it be better at the back or on the roof with a scoop or would this create more drag then on the front what would you guess would be the best location, front, rear, roof or side mounted. It is deffinatly a pain but handy when you get a flat, I suppose you could go without and carry some of that foam emergency stuff not sure how long that would last if you were in the wopwops.

[Frank Lee]

It doesn't need to be a cone; all it needs is sufficient radii on the leading edges to promote smooth flow downstream. On my installation, cover or not, the tire is up above the hood a bit so that flow is shot.

Roof is worse if it adds frontal area.

I like it in front cuz the front needs more weight as it is. Plus the accessibility is good there.

[Sven7]

If you can make the wheel and tire into a teardrop integrated into the hood I don't see any problem with it, but it'll be much more difficult than it's probably worth.

[KamperBob]

Originally Posted by flying kurmaster

I was wondering if anyone thought this would have any benefits, it would serve as a partial grill block especially if there was nice cover over it, and secondly it would extend out in front of vehicle creating a sliciing through the air effect, a bit like the shape of modern trucks protruding down and forward, minus the nice smooth lines of course. has anyone experimented with this, or do you think it would just foul the air and create more drag, what say you ???

I'd love to see some ABA test data.

I've been carrying a small motorcycle across the front of my truck.


I did not do ABA testing but tank MPG data over a few years and several thousand miles suggests the impact is not as bad as one might expect. My "read" of the data shows 16 +/- 2 mpg without the bike versus 15 +/- 2 mpg with it on front. Of course I'm counting on my trailer to clean up the wake.

I did see the engine run hotter with the bike on front. That seems to help FE but I haven't tried to tease that factor out of the data scientifically.

I'm not sure this anecdotal case helps any but there it is.

I suspect there is motivation other than aero for moving the spare up front. Aft to fore axle weight shift for example. I'm curious about the "rest of the story" as Paul Harvey used to say. (wink)

Rock on!
Bob

[aerohead]

If you could lean the spare tire up against the nose of the truck a snap a photo it would help visualizing the concept.
I have the spare on the front of my VW bus,but it's so small in comparison to the overall size of the front end it has little effect.It probably wouldn't be like that in a truck.

[flying kurmaster]

unfortunatly the truck is on a different continent, you can see the kurbmaster in the "exterior sunvisor" thread I started a while back, the tire would not likely go above the hood as Franks says his does, but the more I think about it, if there is no areo advantages putting it up front I think I will concentrate on designing a mount and installing it on the back as there is room there and it may be a better choice for looks. I can block the grill with something else easily enough. I was mostly wondering if there was any advantages to having it upfront, it seems that is not the case and possibly some disadvanteges. 'cheers fk