Scion FR-S vs. Subaru BRZ (drag coefficient 0.27 - 0.29)
 

The following comes from the 2013 brochures.

The Scion FR-S has a Cd of .27 and no rear spoiler.
http://www.blogcdn.com/www.autoblog....on-fr-s-fd.jpg


The Subaru BRZ Premium has a Cd of .29 and no rear spoiler.
http://file.kelleybluebookimages.com...40x480_d4s.jpg


The Subaru BRZ Limited has a Cd of .28 and comes with a rear spoiler.
http://autosportscar.com/wp-content/...Side-Right.jpg


Is it the difference in the front ends, or something else? The numbers don't make sense to me. Same EPA ratings.

Same tire size across all 3 models?

Antenna.

regards
Mech

The FRS does not have a .27 CoeF, it is .29. The GT86 sold in Japan with the belly pans and spoiler has the advertised .27 CoeF. The USDM BRZ limited doesn't have the belly pan so it's .28 CoeF. If you look at the brochure for the JDM GT86 you'll see the spoiler is worth 10 points and the belly pan is worth 10 points. Which gives it the sleek .27 CoeF.

Edit: My mistake, it's not in the brochure. It was in another technical article I read. I'll look for it later.

I was suspicious of that .27 Cd. The Scion brochure does show the belly pans being present, so they weren't totally lying, just had the wrong spec and photo.

Those pans are really worth a .01 decrease in Cd? The first picture is apparently the US version. Just a few center panels makes that much of a difference? I might have to reconsider a belly pan! :)
http://blog.perrinperformance.com/wp...el-550x368.jpg
http://www.mann-engineering.com/site...nderpanels.jpg
http://www.japanparts.com/images/Ima...ase=1&no=43930

Tires are all too-big 215/45-17s. Same antennas too. I think the black car's antenna was a victim of Photoshop.

You mean the JDM car right? One of the things they cut from the FRS was those belly pans.
Eg: Aerodynamics discussion - Scion FR-S Forum | Subaru BRZ Forum | Toyota 86 GT 86 Forum | AS1 Forum - FT86CLUB
I'm not 100% sure on the BRZ Premium or Limited. It's been a few months since I've seen the pictures.


The tires are actually from the Performance package for the Prius, (not available in the US). So even though they are a bit wide, they are LRR. Which is good enough for me.

No, it's the US Scion FR-S brochure that shows the underbody panels. I'm just assuming they copied the wrong info.

Since it's such a good photo of the panels, I'll post it here:
http://img.photobucket.com/albums/09...s/underfrs.jpg

? This is a sports car and you think 215's are too wide? My Cruze Eco has 215/55-17's... a much taller tire for sure but still a 215, and it's an eco-machine. Since my Cruze uses the same size wheel as the FR-S (17x7), my tires are actually wider when measured at their widest point. The Cruze Eco's wheels are much lighter though. :D

The first thing this car needs for better fuel economy is a taller top gear (or a 7th gear), not narrower tires... a manual FR-S is only rated at 30 MPG highway, and a Corvette is rated at 26!

I suppose you could replace those 215's with 185/65-15's and take all the "sports" out of the "car"... assuming a 15" wheel even fits over the brake calipers. :rolleyes:

:turtle:

I actually meant wheel/tire size. I like wide tires and grip around corners. I'd just rather have something like 215/50/15s. Is it wrong to want them on a diesel BRZ? :snail:

A 215/50-15 is only 23.5" tall, that's 1.1" shorter than the already small (by today's standards) 215/45-17 that's on the car. IMO, it wouldn't look very "sports-car like", and isn't that a big part of starting with a FR-S in the first place - the sports car looks?

RE: Diesel BRZ

My personal opinion: It's not healthy to lust after things that we know for sure will never exist! :)

But I don't like the look of 45 series tires! :p

It's because the BRZ is going to the left and the FR-S is going to the right... and as we know the jet stream goes west to east.

:D

If the wheel arches are more or less flush, and/or the floor pan maybe a big part of it. Side taper is hard to know, as well.

A bit more info about that from the Scion website:

MPG[4] (EPA City) (MT/AT) 22 / 25
MPG[4] (EPA Highway) (MT/AT) 30 / 34
MPG[4] (EPA Combined) (MT/AT) 25 / 28

I think they have some AT system that gives better averages than a manual, but I'd like to see an ecodriver's numbers on a manual.

This info is also on the Subaru website.

Also,
According to the first post there Subaru claims:

no underpanel, no wing: 0.29cd
no underpanel, with wing: 0.28cd
with underpanel, with wing: 0.27cd

That's great! I was wondering if it was worth it to have it removed for greater MPG if I was to get this car, though I think it looks a bit nicer without it.

Nevermind eco driver, normal fuel wasting drivers get 30+ mpg with this car, and it'll cruise at 50mpg+ if you're going 50mph. EPA tests are total BS.

The stock spoiler is kind of ugly but some of the aftermarket ducktail spoilers look a lot better and would have a similar effect I imagine :D

I heard on the AT the fd was lower than that of the MT. Idk how true it is but it's something to consider.

Corvette, actually...
 

Make that 29 for the Vette.

Fuel Economy of the 2014 Chevrolet Corvette

The EPA test isn't BS; you just have to understand what it's testing. At no time does it test steady state cruising at 50 mph.

ANY car will beat its EPA highway rating when cruising at 50!

Any idea if these EPA tests take into consideration prioritizing shifting into higher gears for fuel efficiency, or are they shifting up just enough to be in a comfortable gear? Sorry if it's a newbish question but I don't drive stick, I've just seen people skip up to their highest gear once they've reached the speed limit (mostly 45 mph roads).

It's a good question. And no, the way a manual is operated during EPA testing is not particularly efficient.

See: http://ecomodder.com/forum/showthrea...ing-27416.html

nice post / info thanks

overlay
 

Here's an overlay for one of them
http://i1271.photobucket.com/albums/...titled19-1.jpg