hail damage aero advantage

[Chrysler kid]

Prove me wrong, but if I touch the highway I can see 50 mpg easily.

Brings up the question if aero blocking panels should be flat or concave golf ball style.

I know mythbusters did an episode where they dimpled a Taurus and saw a hefty gain in aero effecienCy

My hood roof and trunk are covered in pea size hail damage.

Comparing my logs to other cars that is the only advantage I can think of and how I can average 39mpg on a bad tank in the city

[MobilOne]

I saw the Mythbusters episode that you reference; but, as I remember it, they found no advantage to the dimples. That's IIRC, so correct me if I am wrong.

[Sven7]

I doubt pea sized hail damage is the reason here. Could be winds, speed, state of tune, tires, mods, traffic patterns or any combination of those. Sure, theoretically dents might help, but metal doesn't deform into nice golf ball dimples on impact, and probably doesn't quite capture the ball's aero properties anyway.

It wouldn't be so much about proving you wrong, as it would be to prove you right. I wonder if you did ABA testing as-is, then skimmed clay into all the bodywork holes, if you'd see any difference at all.

[elhigh]

As I recall they did see an improvement with the dimples, but the dimples were several inches across, like softball diameter.

They also wound up adding a few hundred pounds of clay to make it happen, so it may have altered the aero profile in other ways.

I think I have this episode on CD, I'll look for it.

[MobilOne]

Yeah, that rings a bell in my head. IIRC they used a Taurus, covered in heavy clay with tennis ball/baseball/softball sized dimples.

[aerohead]

Originally Posted by Chrysler kid

Prove me wrong, but if I touch the highway I can see 50 mpg easily.

Brings up the question if aero blocking panels should be flat or concave golf ball style.

I know mythbusters did an episode where they dimpled a Taurus and saw a hefty gain in aero effecienCy

My hood roof and trunk are covered in pea size hail damage.

Comparing my logs to other cars that is the only advantage I can think of and how I can average 39mpg on a bad tank in the city

*Dimples trigger a transition from laminar,to turbulent boundary layer (TBL).
*On any given day,if there's any wind at all,the Earth's boundary layer will turbulent and up to half a kilometer thick.
*So basically your car is already immersed in in a TBL by 20-mph and doesn't need any dimples to get as good of an attached flow as it can.
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*If the hail damage IS improving your mpg,it's because it's acting as crude vortex generators (VGs).
*If so,properly sized and placed VGs near the back of the greenhouse would be all that was needed for the same effect.

[Chrysler kid]

Originally Posted by aerohead

*Dimples trigger a transition from laminar,to turbulent boundary layer (TBL).
*On any given day,if there's any wind at all,the Earth's boundary layer will turbulent and up to half a kilometer thick.
*So basically your car is already immersed in in a TBL by 20-mph and doesn't need any dimples to get as good of an attached flow as it can.
-------------------------------------------------------------------------
*If the hail damage IS improving your mpg,it's because it's acting as crude vortex generators (VGs).
*If so,properly sized and placed VGs near the back of the greenhouse would be all that was needed for the same effect.

Thank you sir, I appreciate the science facts as always

Hard to see but I would say marble sized. I'm working on one of my best tanks in the city so far on 93 octane and mmo, and I'm at about 345 miles with a quarter tank left.

I went on a 100 mile commute yesterday in rush hour at a constant speed of 60mph, otherwise my commute is still majority city driving. I did not tail gate or draft on the highway

The only logical way to test my theory is by making a grid pattern on a spare hood and use a center punch to cause dimples. I do not have a hood without hail damage so I can't test my hypotheses

[aerohead]

Bear in mind that the hood in is the forebody region,where it is attacking the air,and in a very favorable pressure gradient,with the surrounding flow 'holding' the boundary layer to the car.You'd never see separation there.
Where you'd need help,is in the aft-body where there's no reason for the air to remain attached unless the turbulent boundary layer could get an extra injection of kinetic energy from the outer inviscid flow.
Scientifically,the hood has nothing to do with fuel economy,only the back of the greenhouse (C-pillars and roof/backlight header area ).
You can see from the Golf/Rabbit that the flow around the hood and over the roof is fine.And your car is 'cleaner' than the VW

The challenge is to keep it stuck over the aft-body.Short of a streamlined body,VGs could help.

[drainoil]

So there is a reason airplanes don't have dimples?

[Chrysler kid]

Ah forgot. This is my first summer without battling egr or iacv lights and I did a spark plug and fuel filter swap.

So the hot weather is why

The car is covered in the roof and trunk too but the 80 degree weather is more logical reason