My review of the 2021 BMW M340i vs my previous 2018 Audi S5 Sportback

  1. The throttle and transmission mapping on the BMW is superior because of how linear the response is. The Audi is a lot more laggy and it took me a while to get used to driving it. It had an annoying lag in D mode that I never really fell in love with. In S mode it was nicely twitchy but that’s not always fun in heavy traffic. Audi sadly hasn’t been to bridge the gap between the two modes where BMW has. The BMW is extremely smooth to the point where it’s dangerously deceptive on how fast you’re going.

  2. Audi wins in the interior for me. Other than the subjective design language, there are more soft touch materials were your hands would normally touch.

  3. The 48v mild hybrid in the 2021 is a game changer for start and stop. I always turned it off in the S5 because of how abrupt it was. No issues in the M340i. Also they took away the button to turn it off but I don’t miss it. All cars with start stop need to have a mild hybrid system. Anything less is criminal.

  4. The adaptive suspension is more comfortable in the Audi than in the BMW. I did get the Adaptive M Suspension option. Can’t imagine going with the regular suspension, as it’s supposed to be even firmer.


I like how the bmw will hold shifts to redline in manual mode vs the Audi that automatically kicks up when you get high enough in the rev range.

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It’s much more of a jekyll and hyde situation with the BMW. In Comfort mode, you can drive around around with a gentle right foot and it feels like a easy to drive, frankly boring luxury car.

Sports or Sports Plus and the shifter in Sports or Manual, it’s almost a different car.

The Audi had two modes - laggy and twitchy. Not much in between. Do not miss that lag at all. I can’t believe they refuse to fix that even though they use the same transmission.


The M340i is deceptively fast. If you think that was an issue with the S4/S5, it’s even more of an issue with the BMW.

But for very different reasons.

Because the Audi’s feel so planted with how Quattro is tuned as well as the sound deadening and isolation, going 70mph around a curve feels like going 45mph.

BMW’s xDrive is more rear biased and feels more playful on the backend. However the throttle and transmission mapping in every mode except Sports Plus is extremely linear and smooth for a high performance car. That means you can smoothly accelerate to 80+ mph without feeling like it unlike in the Audi which has more abrupt changes at each gear shift in sport mode. Don’t get me wrong, the BMW also pushes you back in your seat, but you don’t have to modulate your gas pedal inputs as much and it just keeps on pulling without the same level of feedback.

It’s almost like the BMW is trying to replicate how you would accelerate in a manual car with smoother gas pedal inputs vs an auto where you can modulate the gas pedal in pulses a lot more to get the output you want. Hard to describe accurately.

Very risky for your ability to legally drive.

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Congrats I enjoy mine, as for the suspension I have the passive one and the ride is fine for me, RWD as well and I wouldn’t have it any other way.

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I’m making a, sort of, similar change by replacing a X3 M40i with a SQ5. The comments in this thread are spot on.

The B58 with the ZF8 is probably one of the best powertrains on the market. In fact, I’d argue no one touches BMW in terms of powertrain calibration. Doesn’t matter if the ZF8 is hooked up to the N63 or B48, they’re all fantastic.

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I get to drive a M340xi fairly often and you are correct. It is deceptively fast. Pulls like a freight train on the highway, but I absolutely hate the 48V stop/start system. Just let us turn it off!

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Luckily it’s off in sport plus.

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Really? I love the 48v start stop. It was awful in comparison in the S5. It’s almost seamless in the BMW.

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Some of it might be this being by first ever run flat tires.

Yup, this.

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  1. Also, Audi’s Virtual Cockpit is better than BMW’s Instrument Cluster in both function and customizability. I’m surprised how little you can customize the BMW one.

  2. Conversely, iDrive is more customizable, with more features and the more interesting of the main car software packages compared to MMI.

  3. I love that remote start is much more of a standard feature in dealer inventory than for Audi. The BMW Connect app is more useful (could still use some more features) and less buggy for me. It might be worth paying the subscription fee for me when my free trial runs out.

As much as I love Audi’s design language, I’m turning into a BMW convert pretty quickly.

  1. Seat comfort: Audi wins here. No question. It’s not bad in the BMW, but I don’t understand why the seat cushion is so much harder. It seems like they borrowed seat cushion material from the same supplier for the Accord.

Yep, I swapped out my RF for Michelins PS4S’s, night and day difference. The michelins has enormous grip even in the wet.

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Do you also add a spare tire kit when you switch tires?

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And is it free? Or a tire plug kit at least?

I bought “AirMan ResQ Pro+ Tire Repair Kit” and keep in the trunk.


As someone who owned a B9 S5 coupe and has lots of experience with the M340, I would buy the S5 sportback over the M340 (note I would get the M440 over both and I would probably be driving that instead of a M4 if it came out a little earlier). I just never fell in love with the exterior and interior design of the M340. While M340 is slightly more impressive on paper, if I wanted a true go-fast car I would get a M3/M4, GT4, GT500, etc. The S5 is much more comfortable, has better build quality, more road presence with black optic package, and handles better in adverse weather. It is a near perfect GT-style car IMO. I will admit the turbo-lag is bad in normal mode, but I only drove it in S mode and everything was fine.

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I had a 2018 SQ5 before my 20 M340i - i agree with everything you’ve outlined.
I think what stands out for me is the

  • audio system (I had the B&O in the Audi) - the Audi’s system is SOOOO much better than the Harmon Kardon in the BMW.
  • Ambient lightning was a lot more dramatic in the audi
  • loved my red diamond stitched seats in the audi - made the interior for me

Other than that - BMW all the way - no comparison in driving at all - and sounds so much better. Only thing that keeps bringing my eye back to Audi is their interior design and quality of materials like you mentioned.


Agree with all your points @Bimmer_Daniel

At times, the M340i does feel like an upscale Accord and that’s not very impressive.

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