If you measure "smoothness" with your butt and your fingers it will be entirely subjective and any argument is pointless.

Subaru is known for being a bit rougher around the edges, they have stiffer motor mounts and less dampening in the cabins, Hondas are trying to toe the line between luxury and economy and as such have more damping.

The Honda will "feel" smoother, but what's actually happening in the engine is a lot of extra mass and development time get added to hide the vibrations that occur in the I4 engine arrangement, while boxer engines are dynamically in balance such that they don't need balance shafts or nearly as many tuned mass dampers.

You can say your Honda is "smoother", by most counts most people will agree with you. Saying your Honda I4 is "smoother" than any boxer engine is going to encourage lengthy heated arguments.

How can balance shafts be irrelevant to the subject when they are used for the purpose of "balancing" the rotating mass of an engine that is not balanced by design?
Whereas the boxer engine needs no special device to mask the vibrations.
What you perceive as smoothness is balance shafts, hydraulic motor mounts, harmonic balancers... Etc...
The point is, the boxer engine is inherently smoother by design than any inline 4 banger.. What you feel as the end result is due to many other things which cause NVH..

So in a car designed all about feel, isn't the end result the most important thing anyway? He has a point, Honda motors feel a lot smoother and more refined than this boxer motor. Thing feels like a tractor at low RPMs and like it might explode at high ones. I love my FRS, but if I could put a Honda K20z3 in it I probably would hahaha

My last car had solid steel engine/tranny mounts. The surface of a cup of water in the cupholder looked like a T-Rex was gonna bust out of the trees behind me. Everything about this car is "smooth", IMO. I swear some of you guys must have driven Oldsmobuicks before this. ;)

Agreed, but like I said its my opinion and butt dynamic balancing detector.:party0030:

Depends on the feel you want.. If you're looking for refinement, smoothness and isolation.. get a lexus. or a middle of the road Honda.
If your goal is lightweight, cost, balance..then you get an FRS/BRZ without the frills and with more NVH..
I have owned many Hondas.. they are great cars and Honda makes some of the finest engines on the planet.. They use some clever techniques to refine their engines.. balance shafts, larger crank counterweights, hydraulic motor mounts. All these reduce power, add weight and cost.. yes mounts do account for a power loss.. as the engine moves about instead of transferring its power.. but you dont feel the NVH as much..
Everything is a trade off.. You want handling, response and nimbleness..
its hard to beat the twins.. especially at its price point.. but dont expect a lot of refinement or sub systems designed to reduce NVH.. Thats just not a priority of these cars.. and most appreciate that aspect of the car.. You get real feedback... un-muted

Agreed. I thought the Honda S2000 was one of the sweetest engines besides my BMW 6.

Except for the Honda k20z3 puts down more power to the wheels than this Subaru boxer. I don't disagree with you about the twins having amazing handling and price, but Honda makes the best small motors on the planet, so it was a bit of shock getting into the FRS and noticing just how far ahead Honda was with its engine technology.

And I'm coming from an 06 Civic Si, it's not like I want to drive a luxury car. I'm just saying that Honda motors feel a lot better to thrash around than this boxer ever will.

I owned an 06 TSX(K24a2), with an engine torque damper and I barely notice any extra roughness coming out of it when going up to 6000-7600rpm. This Subaru feels the same as the K24 but only with less torque. I dont know what the OP means by the FA20 engine feeling "not smooth 6k rpm and up" but it sure as hell feels smooth to me.

Coming from BMW I6's I'm a bit spoiled when it comes to smooth motors. I used to sit and bounce off the rev limiter in N just to show how SMOOTH the I6's were to my friends. You just can't beat naturally balances motors.

IMHO, I think the Honda I4's rev's more cleaner than the FA20 does. Or maybe it's just my mind playing tricks on me, but the FA20 doesn't seem to be a "rever" in the likes of the Honda/Toyota I4's. It's still fun to rev the motor though especially the way the boxer motor sings. It's just a different song compared to the others, but none the less beautiful. :happy0180:

I'm with the OP here, compared to my E46 M3 this engine is not what I would call smooth.

Although part of me thinks it's the sounds coming from that stupid sound tube that make it sound less smooth and give it an overall impression of being less smooth than it is.

Either way I didn't buy this car for the motor.

Changed the oil today at 7500 miles and finally redlined it, MAN it was loud and the sound was full and awesome.

Agreed. My WRX had Cusco solid motor/trans mounts with KW coilovers. You felt every single dip in the road in that car.

The FR-S feels very smooth to me. I love how the car feels and drives.

I currently drive an E36 M3 and an 07 Honda k24a8
The inline 6 is naturally balanced and has many large main bearing caps.. A very stout heavy expensive motor which can't be compared to 4 cylinders...
The Honda is smooth.. But mostly muted.. Great torque down low.. But not
Happy up top revving.. Also FWD sucks.. But the accord is about commuting and not "feel".. I like feedback and hearing mechanicals at work..
I'm not expecting a Lexus like experience in the FRS.. I don't want one..

Hahaha. It's true.

I'm satisfied with the engine power above 6k rpm :burnrubber:

Yeah, the OP probably needs to report back after a few quality oil changes. It would be especially unfair if he is basing these remarks on a brand new car that hasn't broken in. Although it still might not be as good as the best inline 4 engines from Honda, Toyota, and BMW.

I do feel that Subaru probably could have done a little bit better with this engine like giving it forged Mahle full floating pistons for lower friction/higher RPM performance but it was obviously made at a cost. But I love how it has good torque down low - I just wish it didn't lose out on that torque in the mid-range.

I never like Hondas till my dad gave me a beater to drive around. Gotta love how much they put in their engines

I have to agree above 6k it's not as smooth as Honda or toyotas. But this is also the first boxer I ever got to play with... So how's a Porsche compare? I've autocrossed a lotus Elise a few times and that revs to 8.5k. And will stay there all day long. This engine just doesn't quite seem like it wants to stay at the higher revs. But i also just got past break in, so maybe 10k down the road it'll be nice and smooth.

You have to also consider that though you may sense the harmonics are not in check ... a dyno will tell the truth.

mine is smooth as silk all the way to red. . which I come within 200 rpm's of everytime I drive it. Am i doing it wrong? :)

want to talk about not smooth. . I had an 11 S4 prior to the FR-S and while the engine was butter at every rpm, the clutch/flywheel felt like it was going to fly out of the car when shifting at high RPM's. . truly terrible.

-Rich H.

#1 - I LOVE my FR-S. Chassis first, engine/trans in a tie for second.

Honda makes great motors. This is not a subjective assertion. Honda and BMW are always at the top of Ward's 10 Best engines. If you haven't had the chance to drive a ITR or S2K, try it. Those engines are made for 7,000+ RPM.

Talk about smooth, I am surprised no one has mentioned about the rotary engine :iono:
Remap the factory ECU and you'll be way past 1,600 RPM before an analog gauge catches up to it.

[ame=http://youtu.be/o9_jVo8CuJs]MAZDA RX-8 Introduction[/ame]