zibby43

As the title says, does the OEM trunk spoiler have a legitimate, measurable impact (however small) with respect to increasing downforce, reducing drag, etc.? Or is it just bling?

I know the C63's spoiler design is different from the one found on the standard W204 C-Class.

Tried searching around but didn't find anything. I know that the massive wing on the Black Series has an impact. I'm talking about the non-BS coupes and sedans though.

The reason I ask is because the new F82 M4 coupe has an integrated spoiler (gurney flap) built into the trunk that does have a relatively substantial aerodynamic impact.

The BMW M engineers claimed that the new F80 M3 sedan has an inherent aerodynamic advantage over the F82, which is why the F80 has a more conventional "attached" trunk spoiler instead.

AMG Boost

Cant say for sure but based on my experience with other cars I would say it does help with the drag coefficient. I doubt it adds any significant down force.

zibby43

Nice. Appreciate the input. It would be interesting to know if upgrading to something like the Mode Carbon rear spoiler has any functional benefits besides looking amazing.

bhamg

Increased downforce = increased drag. A small rear spoiler like the OE lip probably detaches the airflow from the trailing trunk edge, thereby reducing drag.

zibby43

Yeah I never insinuated otherwise.

Regarding the second part, good to know.

ChrisD63

ehh I think it is entirely cosmetic!

m a x i m u s

I venture to say that it's purely cosmetic. the airflow up and around the rear of the car isn't efficient enough to take advantage of any little aero flaps and flicks. this isn't an f1 car, unfortunately.

-=Hot|Ice=-

MB needs to start offering a carbon spoiler, and the like. They are starting to use it is starting to use it for both aesthetic and purposeful reasons.

zibby43

You very well could be right.

Although you'd be surprised by some of the aerodynamic-related claims that manufacturers are making regarding daily drivers. For example, with the BMW M Performance parts for the M Sport F30 3er, BMW claims that the rear CF spoiler and front splitter can each generate an additional 25-30 percent of downforce at X speed.

Who knows whether those claims are accurate or mere "puffery." If they are accurate, those are some relatively substantial improvements (with respect to grip anyway). BMW M has really been expanding the M Performance product line for all of its models.

It would be nice if AMG offered performance part upgrades a la carte at reasonable costs for those who may regret not getting X option when ordering (or for those who miss out on an option because they buy off the lot).

sinape62

Agree. A few years ago I troubleshooting a Boeing 717 roll problem... We installed wing tufts to get an idea of the airflow over the flaps when they transitioned from 18 to 25 degrees... When the flap got around 22 degrees the tufts became erratic, airflow disruption. I think the same thing goes on with the mode Carbon spoiler that I have. I noticed one day when we had snow drifts, I could see the snow drifts (looking from my rear window) buffeting/ disturbed between the window and the spoiler... Ie it wasn't smooth... I wanted to video tape it, but the weather wasn't the same the next day. In my day job, I deal with aerodynamics from time to time... In fact we were talking about laminar flow today on the 787. (Off topic)

Statically, the larger spoilers look good. Dynamically, probably not improving anything.

vtune

when i watch burnout videos the lip spoiler has a very clear impact on the flow of smoke. at higher speeds i am sure it would have a positive impact on downforce

snowmuch

On my c300 without the spoiler at 150km/h the car is little floaty, I do notice a difference after the spoiler was on.