The M340i and M3 are both excellent performance cars from BMW. They're both enthusiast cars that deliver great performance, handling, and driving experience. While both carry an M-badge only one of them is truly an M - the BMW M3. The M340i is known as an M-Performance car (or "M-Lite"), but isn't truly built or designed by the M division for motor racing. In this article, we compare the M340i vs M3 including specs, performance, driving experience, price, and more.
Note: Much of this article also applies to the M440i vs M4. The M340i and M440i are nearly identical less the door count. The same applies to the M3 and M4.
M340i vs M3 Specs
In this article, we'll look at both the F80 and G80 M3 as comparisons to the G20 M340i. The newest G80 M3 is really the better comparison based on years of production. However, given the price differences, it's fair to include the F80 M3 since they're a bit older and pricing is more in line with that of the M340i. Anyway, pricing is a topic that will come up later in this article. For now, let's jump in and look at M340i vs M3 specs:
|F80 M3||G80 M3||G20 M340i|
|Displacement||2,979cc (3.0L)||2,993cc (3.0L)||2,998cc (3.0L|
|Aspiration||Twin turbo||Twin turbo||Single turbo|
|Horsepower||425-453 HP||473-503 HP||382 HP|
|Torque||406 lb-ft||406-479 lb-ft||369 lb-ft|
|0-60 MPH||4.0 to 4.3 Seconds||3.4 to 4.1 Seconds||4.1 to 4.4 Seconds|
|Figure-8 Time||24.0 Seconds||23.3-23.8 Seconds||24.7-25.0 Seconds|
|Redline||7,600 rpm||7,200 rpm||7,000 rpm|
|Weight*||~3,600 lbs||~3,850 lbs||~3,850 lbs|
|Fuel Economy||17/24 MPG||16/23 MPG||22/30 MPG|
*Weights are rough estimates and can vary a lot depending on options. All else equal, the G80 M3 and G20 M340i come it at roughly the same weight and are about 200-250 lbs. heavier than the F80 M3.
All cars share the same basic 3.0L turbocharged inline-6 design with direct injection, DOHC, VVT, and VVL. However, the F80 and G80 M3 receive twin turbo engines instead of the single turbo design of the M340i. The S55 and S58 are also BMW M designed engines while the B58 is a standard engine.
The M3's deliver more revs, power, and torque. 0-60 times are from BMW and are generally on the conservative side. For example, MotorTrend was able to achieve a 0-60mph time of 2.98 seconds in a 2022 M3 Competition. The gap only widens in favor of the M3 when you look at 1/4 mile times.
BMW Figure-8 & Lap Times
Motortrend tests quite a few cars around their basic figure-8 test track. It's a very short track, so times are clumped together pretty close. It was actually an M440i xDrive that achieved the 24.7 second time, and a RWD M340i that managed 25.0 seconds. The G80 M3 xDrive achieved 23.3 seconds and the F80 M3 splits that difference at 24 seconds flat.
For reference, an E92 M3 took 24.4 seconds around the figure-8. A Porsche GT2 RS is tied for the track record at 21.9 seconds and a 2019 Toyota Prius managed 26.3 seconds. Ultimately, a two generation old E92 M3 is still able to outpace an M340i. 1.4 seconds separate the G80 M3 and record holding Porsche 911 GT2 RS; the same gap that separates the M340i vs G80 M3.
At the Virginia International Raceway, the G80 M3 Competition xDrive managed a 2:53 lap compared to 3:00 for the F82 M3 and 3:03 for the M340i xDrive. Looking at exact seconds it was only 2.5 seconds behind the F82 M4 and 9.7 seconds behind the G80 M3.
It's a very respectable result for the M340i, especially compared to the F82 M4 that has less weight and more power. The xDrive certainly helps, though. The M340i vs M3 didn't fare quite as well against the newest G80 model.
BMW M340i vs M3 Differences
Despite the many similarities of these BMW 3-series models they do have some very notable differences. A true M-car still aims to be the "Ultimate Driving Machine" and a true enthusiasts car. Some of this is evident in transmission options, brakes, engines, and more.
Other aspects of the M340i vs M3 simply can't be explained on paper. The M3 delivers a connection with the driver that is hard to match. In the next sections, let's look at a few of the notable differences between the two M-badged cars.
Manual or Automatic Transmission
One consistent complaint about the BMW M340i or M440i is the lack of a manual transmission. These cars are only available with a ZF 8-speed automatic. It's an excellent transmission and some enthusiasts - like myself - actually prefer an AT. However, it's surely a deal breaker for those who still appreciate the deeper connection of a 6MT.
Enter the M3. Both the F80 and G80 models are available with a good old fashioned 6MT, and the M3 will likely continue to offer a manual option.
"M-Lite" vs True M Cars
True M cars only carry one number. The M2, M3, M4, M5, X3M, etc. are cars designed and built by BMW's M division. Other BMW's that carry the M-badge - like the M340i, M440i, & M550i - are commonly known as either M-performance or M-Lite. They are not built by the legendary M division. They are standard BMW's with a few extra performance touches.
The M340i receives M Performance brakes, M sport exhaust, larger wheels and better tires, additional driving modes, and a few other changes. However, these upgrades still don't compare to the M3. For example, the M340i M Performance brakes are not the same as the M3 brakes. A G80 M3 uses 6-piston calipers, large two-piece drilled rotors, and higher performance pads. Meanwhile the M340i brakes are 4-piston Brembo brakes with smaller two-piece blank face rotors.
Brakes on the M340i are still exceptional. They aren't on the same level as the M3, though. That concept applies to just about everything. The M models have lots of design aspects that make them superior performance cars in just about every way possible.
BMW S55, S58, & B58
BMW's S58 might not even be a fair comparison in this discussion. The B58TU in the M340i and S55 in the older F80 M3 are both great engines. We don't believe the S55 is exciting enough to buy an F80 M3 over the G20 M340i just because of the engine. Quite the opposite is true of the BMW S58. It very well may go down in history of one of the greatest engines of all time. It's pretty close to a full blown race-spec engine that meets emissions.
The S58 is already able to make 750+whp on stock turbos. A Red Bull drift team pushed the engine to over 1,000hp. Dozens of G80's have already cracked into the 9's at 135-140+mph in the 1/4 mile. Most of those were full weight xDrive models with nothing more than a tune, intake, downpipes, and E85.
It's clear the M3 has the advantage when it comes to M340i vs M3 engines. The B58TU is a great engine, too. The M340i can make 450-500+whp on the stock turbo and 600-700+whp is very possible with an upgraded turbo and proper supporting mods. Anything further will require a built engine for reliability and longevity. The M3 can achieve those numbers with a stock engine, stock turbos, and a few basic bolt-on mods.
The M3 Is The True Drivers Car
A lot of M340i vs M3 differences can't just be explained on paper. It's best to test drive both cars - if possible - and decide which one best suits you. The quicker 0-60mph, 1/4 mile, and lap times don't paint the full picture for the M3. After all, most people won't even utilize the full capability of an M340i on the street, let alone the BMW M3.
The chassis differences have a large impact on how each car feels, though. An M3 generally provides more feedback, response, and connection to the driver. Some of that can even be felt during normal daily driving and not just when pushing the cars to the limit. Again, it's hard to explain well on paper and something each person needs to experience. True enthusiasts will likely feel the difference immediately.
Point is - the M3 is the full package. It delivers more performance, better handling, and a more connected and visceral experience. The M340i still delivers much of that at a high level and will likely be more than enough for moderate enthusiasts. However, die-hard enthusiasts might have a hard time getting back into an M340i after experiencing a true M-car.
BMW M340i and M3 Price
Finally, this is where things turn in favor of the BMW M340i. For one, an M340i should be an easier car to find and purchase. I am currently on the waitlist for a G80 M3 from our local dealer here in Denver. I joined the waitlist in May 2022 and it's likely I won't actually get the M3 until sometime around May-July of 2023.
The M340i is also less expensive than the M3. MSRP for a 2023 M340i starts at $54,850 or $56,850 for the xDrive model. An M3 starts at $72,800 with a manual transmission and runs up to $80,800 for the Competition xDrive model. That means you'll be spending about $15,000 to $25,000 more on the BMW M3.
In the used market, as of November 2022, most G80 M3's are $80,000+. Some 2020 M340i's can be had for less than $50,000. You can also find some F80 M3's for less than that, but most will be around 2015-2017 with 50,000+ miles.
M340i vs M3 Summary
Ultimately, the BMW M3 carries the true M badge; it's an M car from top to bottom. The M badge is debatably the most legendary badge in the world for good reason. It is the true definition of the "Ultimate Driving Machine" and a legacy that can be challenged by few to none.
Jeremy Clarkson loathes BMW but that didn't stop him from saying, "The BMW M3 is the best car - and always will be, and there's no point in ever thinking otherwise." The M340i is a great car, but it won't ever garner that same respect. It doesn't matter whether or not (which, you can indeed) easily mod the M340i to be faster than a true M car. The M340i will never be an M3.
It sits on the basic yet stout G20 3-series chassis. It gets a great engine in the B58. However, neither of those are true M products as are the F80 M3, G80 M3, and S55/S58 engines. That said, the M340i will deliver performance to satisfy a vast majority of drivers. You can't ask for much more from a daily driver.
However, if you're looking for the legitimate "Ultimate Driving Machine" then you won't be happy knowing something better exists. That is the market the M3 satisfies. It's overkill for most but it's the car that makes BMW's slogan possibly the truest in the automotive industry. It truly is the "Ultimate Driving Machine" and we wish you the best of luck in finding a more well-rounded performance car. The BMW M3 is the better car here - by a pretty significant margin.