If the BRZ was an American car would you have bought it?

[sierra]

Originally Posted by Admiral Ballsy

"Balanced" means different things to different people. Boxers are the only four-cylinders with perfect dynamic balance absent external aids. But since all currently produced I4s (at least over 1500cc or so) have balance shafts, it's a moot point. Lots of more-than-four cylinder engines are perfectly balanced - inline sixes, dual-plane V8s, all 12s.

I think more important than "balance" is "smoothness". Fours will never feel perfectly smooth since there's that instant every 180 degrees of crank rotation where there's no power stroke in progress. By contrast, V6s cannot be balanced without shafts, and AFAIK no currently-produced V6 has one. But if you drive a high-end V6 car, you'll find no evidence of vibration. A lot can be done with mount technology.

The low CG is only useful if you can actually do something with it. Flat engines are hard to package; they're very wide (the FA20 is wider than a typical 2.0L I4 is long). They realistically have to be oriented longitudinally, which makes same-end drive problematic; the engine either has to be moved far forward (or rearward, in the case of the 911), or it has to be raised to allow space under for driveline (Subaru AWD). Both of those create chassis balance issues, which kinda negates the potential low CoG of the engine assembly.

The only places where the flat engine can really be effectively used are opposite-axle drive (BRZ), or midships placement (Cayman/Boxster/Ferrari BB) - niche applications, these days.

So you've got an engine that's comparitavely expensive and complicated to produce (twice as many heads and sets of valvegear) complicated to package (intake and exhaust paths), almost certainly heavier than a comparable inline...and it's got very limited application where its advantages shine.

The boxer configuration is perfect for the BRZ and the Cayman/Boxster; beyond that, not so much.

Toyota/Honda/Nissan/GM/Ford/Chrysler/VW/FIAT are all much bigger than Subaru; if there was a compelling reason to use a flat architecture (outside of the niche applications with Porsche), I'd think at least one of those groups would be smart enough to do so.

Good points.
The inherent balance is important as by not requiring balance shafts etc it has a much lower rotating mass, with all the benefits that brings to performance and economy and is also lighter.
Although the boxer is wide and needs to be mounted across the body, it's compact in it's height and front to rear. It would be a great choice for a hybrid charging engine, keeping everything super low for interesting body shapes.
Would it be that hard to mount one where it is in the 86 and get a gearbox in there for FWD?

In theory 4 cylinders are less smooth than 6 or 8 but in practice there's more lost in UEL headers and most 4's are very smooth these days.

Nearly forgot one huge advantage!
It's so good to have something that's different!!!!!!

Thanks for that very interesting valid reply and sorry we are off topic guys!

Edit. A boxer engine was fitted to the front wheel drive Alfasud from 1971 - 1989 with almost 900,000 being built. It was one of Alfa Romeo's most successful models so it certainly can be used in conventional cars.