BMW M340i G20
B58 straight-six and an M Sport diff in a 3 Series — most of an M3 on a real road, none of the grille.
The 3 Series with the six-cylinder and the locking diff, for people who decided the M3 was more car than the road needs.
32 reviewers · 70 videos · 21 hours watched
Reviewers strongly agree on its performance and daily drivability, but split on handling and fun to drive.
across 32 reviewers
"Handling is mind-blowing. There is no body roll whatsoever. And the steering is super quick, super precise, and very responsive as well."
Faisal Khan · ▶ 34:12"That front axle's just taking all the fun out of this car."
Driven+ · ▶ 10:24"the m3 40i is by far the most dynamic most engaging and most fun"
SpeedLabs // MotorEnvy · ▶ 6:28"It's just going to fry its tires. It looks loose on the rear, and the suspension just looks a little soft."
Driven+ · ▶ 10:52"This is the only car which feeds extreme value for money because the kind of performance which BMW is offering you for the price is absolutely unmatched."
Faisal Khan · ▶ 26:52"the list price of this car in three years has gone up 360 000 Rand"
Cars.co.za · ▶ 21:45Performance
4.5/532 of 32 reviewersstrong consensus“B-58 made it to the ZF8 speed is such a money combination.”
positive · Jubbal & Cars · ▶ 3:36“Absolutely bonkers performance. This engine is unbelievable. The way it pulls blows your mind completely.”
positive · Faisal Khan · ▶ 11:47“it's a very well balanced car this but you just cannot help to Chuck this thing around and listen to that straight six noise”
positive · Driven+ · ▶ 15:08Handling
4.0/532 of 32 reviewerssplit“Handling is mind-blowing. There is no body roll whatsoever. And the steering is super quick, super precise, and very responsive as well.”
positive · Faisal Khan · ▶ 34:12“handling is going to be very good we have the M sport brakes as well so it it gives you those sporty handling characteristics”
positive · Bros FOURR Speed · ▶ 11:38“The body stays nice and flat through the bends gives you loads of confidence”
positive · carwow · ▶ 6:51Fun to drive
4.5/532 of 32 reviewerssplit“the m3 40i is by far the most dynamic most engaging and most fun”
positive · SpeedLabs // MotorEnvy · ▶ 6:28“This car is so enjoyable to drive. It's mindblowing. The motor is so sweet.”
positive · Faisal Khan · ▶ 15:42“if you want something a little bit more laid-back but still has some performance and potential to it you can go with the m340”
positive · Bros FOURR Speed · ▶ 14:54Daily drivability
4.5/532 of 32 reviewersstrong consensus“this car gives you this balance where it's it feels far less compromised on the street.”
positive · Jubbal & Cars · ▶ 12:00“it incorporates power comfort and usability in a better way than the M3”
positive · Driven+ · ▶ 3:45“the m340 is going to be a little bit more laid-back a little bit more comfortable I will say for daily driving”
positive · Bros FOURR Speed · ▶ 10:28Value
4.0/532 of 32 reviewerssplit“This is the only car which feeds extreme value for money because the kind of performance which BMW is offering you for the price is absolutely unmatched.”
positive · Faisal Khan · ▶ 26:52“you can get a fully speced m340 for less than the M3 tunit and get some of that power to almost match the M3”
positive · Bros FOURR Speed · ▶ 15:17“m340i Well, and it will save a lot on both beginning and later during exploitation”
positive · Autowizja · ▶ 14:44The G20 M340i is a 3 Series built around one decision: keep the straight-six. The B58B30O1 is the second-generation B58 — closed-deck aluminium block, single twin-scroll turbo, water-to-air intercooler packaged in the intake plenum — and it is the reason the car exists. It pulls from low revs with almost no lag and stays smooth to the top, where most rivals' fours and V6s get coarse.
Mechanically it is more than a 330i with a bigger engine. The M Sport differential is an electronically controlled locking unit, standard on every car, and it is what lets the rear-drive version put its torque down out of a corner. Most markets get xDrive only; the US also gets rear-drive. The gearbox is the ZF 8HP, and BMW's calibration of it is the reference for the type.
Where it places in the lineage: this is the car the old six-cylinder 3 Series became once the M3 moved upmarket in size, weight and price. It is softer and quieter than a G80, with less front-end bite, and that is the point.
The facelift in 2022 changed the cabin far more than the hardware.
Hear it in the reviewer’s words
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No manual gearbox in any market. The curb weight shown is the US xDrive car's; the US rear-drive car is about 120 lb lighter. A 48V mild-hybrid system joined the B58 from the 2021 model year. The 2022 facelift (LCI) replaced the separate instrument cluster and screen with a single curved display and moved the climate controls into it, and swapped the gear lever for a toggle. Variable sport steering is quick but is the part of the car reviewers most often call numb. The G21 Touring is not sold in North America.