[chicagoshark]

my17 340i, x drive, mineral grey with brown. M sport, THP, 442 orbit Grey, blacked out grill...

Initially, my intention was to put a carbon fiber spoiler on it, and turns out that that has to be put on at the dealer. So as I am waiting for my car, I'm now starting to rethink the whole spoiler thing. Looks good without and looks pretty cool with it, but I'm not necessarily going for the fast and furious look ha ha....

Would end up looking something like this minus the pink license plate bracket.

Thoughts? Spoiler or no spoiler...

Hmm. Picture didn't attach

[XRAVE]

Originally Posted by chicagoshark

my17 340i, x drive, mineral grey with brown. M sport, THP, 442 orbit Grey, blacked out grill...

Initially, my intention was to put fiber spoiler on it, and turns out that that has to be put on at the dealer. So as I am waiting for my car, I'm now starting to rethink the whole spoiler thing. Looks good without and looks pretty cool with it, but I'm not necessarily going for the fast mysterious luck ha ha....

Would end up looking something like this minus the pink license plate bracket.

Thoughts? Spoiler or no spoiler...

Hmm. Picture didn't attach

Get the spoiler. I have it and it makes a world of difference in terms of looks. If your leasing, its basically going to cost you nothing. I can't tell from the picture if thats the included spoiler or the optioned one. Mine seems to be a lot bigger than that.

BTW the dealer is lying to, it can be installed at port. I did the paint matched one but others got the carbon fiber one installed at port.

[Gingerkid]

100% personal preference... that said, my vote is without spoiler.

[Herakles]

No brainier def spoiler

[goj]

I love the look of the spoiler

[chicagoshark]

It was a long time ago, so I don't totally remember. But I think the paint matched one was able to be put on at the port but for whatever reason it was not letting them do the carbon fiber one. I don't see why they would lie to me about it.

[Big Nodge]

It might have been an honest mix-up in your case, but FYI dealers often try to convince you to get accessories added at the dealership as opposed to at the port. Mine did, telling me many things that were straight-up inaccurate in the process. I held out and got everything done at the port. I think the labor rate built into the MSRP of the port-installed stuff is quite low so they can make more by getting you to install it at the stealership.

[Wires]

Just hit eBay. I did the M3 looking one, it came perfectly color matched for Mineral Grey, and had the 3M double sided tape included.

Just had to wipe the trunk edge with rubbing alcohol, put on two rows of tape on the bottom of the spoiler, line up one side, start pulling the tape cover. Stupid easy to install (15 minutes or less), and in less than a day, that 3M tape has it "permanently" mounted to the trunk lid.

I bought the one off ebay that was coming from the US (turns out it has FedEx'd from Taiwan though). Price is typically $80 painted, most are free shipping (mine was $55 for shipping though). The 3M tape is only $6 at any autobody store. Carbon fiber are around $130. Fit was absolutely perfect, so was the paint color/finish.

[XRAVE]

Originally Posted by chicagoshark

It was a long time ago, so I don't totally remember. But I think the paint matched one was able to be put on at the port but for whatever reason it was not letting them do the carbon fiber one. I don't see why they would lie to me about it.

Money, laziness, or ignorance.

mtx450 was able to add it on at port. I also know my dealer told me I had the option, however I went with paint matched.

If your leasing, its a no brainier as your paying 34-36% of something over 36 months vs paying it all upfront. It also is now on the sticker of your car which adds to the MSRP.

[BEAR-AvHistory]

Port installs are no charge & you can still hammer the dealer on the basic price of the item.

[munu]

I recently bought carbon fiber spoiler similar to what you have in your picture from ebay. I was around $120 and installation was 10 minutes work.
It looks great, totally changed the looks from the back. My vote is go for it.

[Jaghave]

Unless the spoiler greatly improves handling or traction I say no spoiler since all your doing is adding weight.

[donsbabybeamer]

Have CF spoiler (port installed) on my Alpine White 428 looks incredible, class without glitz. It will make your drive standout in a good way.

[metallicpea]

I always prefer no spoiler. They usually look like an afterthought. I've actually taken them off previous cars. But of course it's what you prefer that matters.

[XRAVE]

Originally Posted by Jaghave

Unless the spoiler greatly improves handling or traction I say no spoiler since all your doing is adding weight.

In theory the spoiler should make your car more aerodynamic and stop the car from creating lift.

The gains, even if small, outweigh (literally) the small weight gain.

Not why I opted for it but it does serve a purpose.

[metallicpea]

Actually, it is less aerodynamic, but the main purpose is to make the car more stable at higher speeds by transferring the force from the air down to create downforce on the rear wheels and suspension. All about high speed traction and stability.

I took the factory one off my Mustang many years ago. It was larger than the ones seen on our BMWs, and the Mustang was known for being a bit squirrely at high speed, so I could certainly tell a difference after 100 mph. At 125 that car was too loose to feel safe without the spoiler. Don't expect that much difference for the F30 since it is rated to 155 on certain models without a spoiler, but they do have a purpose.

[donkey]

+1 for spoiler, very happy with mine.

[XRAVE]

Originally Posted by metallicpea

Actually, it is less aerodynamic, but the main purpose is to make the car more stable at higher speeds by transferring the force from the air down to create downforce on the rear wheels and suspension. All about high speed traction and stability.

I took the factory one off my Mustang many years ago. It was larger than the ones seen on our BMWs, and the Mustang was known for being a bit squirrely at high speed, so I could certainly tell a difference after 100 mph. At 125 that car was too loose to feel safe without the spoiler. Don't expect that much difference for the F30 since it is rated to 155 on certain models without a spoiler, but they do have a purpose.

Spoilers create little to no down force and do make it more aerodynamic by reducing drag. Less turbulence behind the car. Your MPG would go up with a spoiler.

They are really meant to reduce the lift caused by the shape of the car. This is a big misconception. Look at F1 cars vs NASCAR. NASCARs can lift off the ground due to lift without a spoiler. A properly placed wing (airfoil), like those on F1 cars, produce down force.

You can't compare a mustang to an F30, the shapes are completely different. A mustang is so poorly designed that at high speeds it creates a tremendous amount of lift without a spoiler. Also if you look at an F30, it does have a small lip on the trunk that acts as a spoiler. The Mustang is so unbalanced (previous models) that any modification makes a drastic change. BMW's are already stable so an increase may not be detectable unless on the track.

Spoiler = Less Drag/Less Lift/No downforce/More MPG
Wing (airfoil) = More Drag/Tons of Downforce/Less MPG

BMW even says on their website not to add the spoiler without the front splitter as it makes the car aerodynamically unbalanced. Great marketing or products that actually work? You'll have to ask a BMW engineer on that one.

In the end and to not get this off topic, spoilers (to me), look awesome and have a lot more positives than negatives.

[metallicpea]

Yes, to be fair, we would need to measure the drag with and without it to determine the effect is has on aerodynamics. Front spoilers are usually designed to reduce drag, but that is less often the case in the rear. Sometimes they have no functional design intent at all, but often they are added to the faster models to keep them stable at higher speeds. Reducing lift vs creating downforce has the same functional result and without measurements we cannot say what change this has on drag.

I should have said - "usually it is less aerodynamic", as if it is not designed as an integral part of the aerodynamics of the car it is more likely to have a negative effect.

If designed as such, spoilers are intended to reduce drag, but this is the case less often than not.

I did say above that I don't expect the F30 rear spoiler to have the same effect as on a Mustang.

Just trying to keep us from assuming it has an aerodynamic benefit.

[metallicpea]

BTW, I'm not sure I follow your F1 vs NASCAR analogy, but NASCAR rear deck spoilers do in fact create downforce. Those cars have trouble lifting off the ground when they are traveling in a direction other than forward and the downforce is lost.

[XRAVE]

Originally Posted by metallicpea

BTW, I'm not sure I follow your F1 vs NASCAR analogy, but NASCAR rear deck spoilers do in fact create downforce. Those cars have trouble lifting off the ground when they are traveling in a direction other than forward and the downforce is lost.

Spoilers create no downward force, it's huge misconception that because it's angled like that it causes drag and pushes the car down. I'm not getting into a whole discussion about lift but you need air moving on both sides of the spoiler to create a force. Spoiler is all about redirecting the air.

Reducing lift and creating downforce isn't the same. By reducing lift, the car will never weight more than it did at standstill. With a wing (airfoil), the car weights significantly more than at rest.

See the image below, in spoiler, the air flow never touches the spoiler but the airflow does hug the wing.

[metallicpea]

I guess the misuse of the term downforce is rampant. NASCAR engineers use that term all the time, but I see the difference you are referring to.

Often even professionals use downforce to describe any state with more force at the wheels than any arbitrary starting state, regardless of weather it is more or less than standing still.