BMW X3 M40i vs. Mercedes GLC 43 AMG Comparison

The BMW X3 M40i and the Mercedes GLC 43 AMG are strong contenders in the performance SUV segment. Both offer immense performance just a step below full-fledged M and AMG models in a practical SUV with plenty of interior amenities.

How do they stack up against each other in terms of power, handling, drivetrain, tuning, interior, reliability, and price? Full X3 M40i vs. Mercedes GLC 43 AMG comparison.

BMW X3 M40i vs. Mercedes-Benz GLC 43 AMG Specifications

Feature2023 BMW X3 M40i2023 Mercedes GLC 43 AMG
Horsepower382 hp @ 5,800-6,500 RPM385 hp @ 5,500-6,000 RPM
Torque369 lb-ft @ 1,520-4,800 RPM384 lb-ft @ 2,500-4,500 RPM
0-60 MPH acceleration4.4 seconds4.7 seconds
Engine Layout and Displacement3.0L Turbo Inline-6 (B58)3.0L Twin-Turbo V6 (M276 DE 30 LA)
TransmissionZF 8HP 8-speed automatic9-speed AMG Speedshift automatic
DrivetrainxDrive AWD4MATIC+ AWD
Dimensions (Length x Width x Height)186.1″ x 74.7″ x 66″183.5″ x 74.4″ x 64.5″
Curb Weight4,391 lbs (1,992 kg)4,190 lbs (1,901 kg)
MSRP~$56,600 USD~$64,500 USD

X3 M40i vs. GLC 43 AMG Power & Performance

The BMW X3 M40i outputs an impressive 382hp between 5,800-6,500 RPM and 369lb-ft of torque from 1,520-4,800 RPM. This enables the B58-powered X3 M40i to sprint from 0-60mph in a swift 4.4 seconds.

On the other hand, the Mercedes GLC 43 AMG powered by the M276 DE 30 LA engine generates a slightly higher 385hp at 5,500-6,000 RPM and 384lb-ft of torque between 2,500-4,500 RPM. The GLC 43 can achieve 0-60mph in just 4.7 seconds, slightly slower than its BMW counterpart.

The B58 of the X3 has more low-end torque and this may be the main contributor to the faster 0-60 mph acceleration figure. Another advantage of the B58 is the inherent smoothness in power delivery when compared to the V6 of the GLC 43 AMG.

bmw x3 m40i b58 engine
The M40i is powered by the B58B30O1.

Both have similar power outputs but the X3 M40i accelerates faster to 60 mph due to higher low-end torque

The 0-60 mph figures are surprising considering the higher curb weight of the X3 M40i. BMW is famous for underrating the power output of its engines so it wouldn’t surprise us if the true power output of the X3 M40i is closer to the 400 hp mark.

X3 M40i vs. GLC 43 AMG Tuning & Modifications

If you want to tune and modify the engine for increased power, the BMW X3 M40i is the best choice. The B58 engine is a popular choice not only among BMW enthusiasts but also for tuners looking for a powerplant with tons of untapped power potential.

The B58 in the X3 M40i has large aftermarket support, which means plenty of aftermarket upgrade parts are available. Similarly, there are many off-the-shelf tunes available for the engine.

The X3 M40i has a larger tuning community. Modifications and tunes are very cost-effective for the B58.

On the other hand, the Mercedes GLC 43 AMG, powered by the M276 DE 30 LA V6 engine, doesn’t have the same level of tuning support. Its engine is also highly receptive to modifications, but options are less abundant and often more expensive.

The M276 DE 30 LA is an open deck engine which could make it less than ideal for heavy tuning. The B58 is a closed deck engine.

X3 M40i common modifications:

Common tuning mods for the X3 M40i include a tune, a catless downpipe, upgraded intercooler, transmission tune, and an upgraded fuel pump. If you’re looking to get the absolute most power out of the B58, you can opt for a turbo upgrade.

b58 catless downpipe
A catless or high-flow downpipe is a common mod for the X3 M40i.

GLC 43 AMG common modifications:

The GLC 43 AMG can be modified similarly, with upgraded catless downpipes accompanied by a tune. A full suspension upgrade is also a common mod.

X3 M40i vs. GLC 43 AMG Exhaust Sound

The BMW X3 M40i’s B58 inline-6 engine delivers a deep and refined exhaust note that gets louder with explosive upshifts while in Sport mode. In contrast, the Mercedes GLC 43 AMG’s M276 DE 30 LA twin-turbo V6 produces a throatier and more aggressive soundtrack at all times.

Both SUVs have great exhaust notes, balancing aggressiveness with refinement

Both are 6-cylinder turbocharged engines but the inline-6 of the BMW produces a deeper note than the V6 in the Mercedes. The V6 on the GLC 43 AMG on the other hand sounds raspy in comparison.

Ultimately, choosing between the smooth sound of the inline-6 of the X3 M40i or the growling V6 of the GLC 43 comes down to personal preference.

X3 M40i vs. GLC 43 AMG Transmission & Drivetrain

The BMW X3 M40i is equipped with the ZF 8HP 8-speed automatic transmission while the Mercedes GLC 43 AMG features a 9-speed AMG Speedshift automatic. Both SUVs have an all-wheel-drive drivetrain as well, xDrive on the BMW and 4MATIC+ in the Mercedes.

The BMW X3 M40i’s eight-speed automatic transmission pairs perfectly turbocharged 3.0-liter inline-six engine. It is one of the best 6-cylinder powertrains available, with very fast shifts in sports mode and relaxed and smooth gear changes when in comfort mode.

The ZF HP8 in the X3 M40i is a better transmission. Both SUVs have sports-oriented AWD systems but xDrive sends more power to the rear wheels

The 9-speed AMG Speedshift automatic in the GLC 43 AMG also shifts very quickly in its own right, but it is generally considered a less refined transmission at low speeds.

We prefer the ZF 8HP unit in the X3 M40i, as it isn’t only a fast and smooth transmission but it has also proved its reliability even at higher than stock power levels.

BMW’s xDrive and Mercedes’s 4MATIC+ work similarly in both SUVs, but the xDrive system in the X3 M40i sends more power to the rear wheels, giving it a tail-happy character, especially in Sport+.

X3 M40i vs. GLC 43 AMG Suspension & Handling

Compared to other SUVs, both the X3 M40i and the GLC 43 AMG have a firm suspension to help them stay stable despite their high center o gravity.

Fortunately, both offer adjustable dampers. Drivers can switch between soft dampening for comfortable cruising or rough roads and a more firm dampening for spirited driving and a more precise steering feel.

Both are stiff SUVs but the GLC 43 AMG offers more adjustability and a firmer ride in Sport+ mode.

The GLC 43 AMG has an additional feature: it is available with an optional air suspension system. This air suspension system can adapt to changing road conditions and driving styles, providing a much more adjustable ride compared to the standard suspension.

X3 M40i vs. GLC 43 AMG Exterior Design

BMW has done an excellent job with the LCI X3 M40i, featuring an aggressive design that accurately represents the capabilities of the SUV. Thankfully the X3 M40i hasn’t been affected by the controversial massive grilles of some newer BMWs.

The X3 M40i exterior reflects its sporty nature while the GLC 43 AMG looks more subdued and elegant.

bmw x3 m40i lci and mercedes glc 43 amg front side view comparison

The Mercedes GLC 43 AMG, with its understated and elegant looks, may appeal to those who prefer a more subtle vehicle. The GLC 43 AMG exterior design reflects more Mercedes luxury than AMG sportiveness. At least until you look at the “Biturbo” badge and the massive front brakes.

X3 M40i vs. GLC 43 AMG Interior & Comfort

Both SUVs offer a similar level of interior amenities. The infotainment systems in both vehicles provide a wealth of features, but the iDrive system in the BMW X3 M40i is arguably more intuitive and user-friendly than the touchpad-based system in the Mercedes GLC 43 AMG.

2023 bmw x3 m40i vs 2023 mercedes glc 43 amg interior comparison

The interior of the GLC 43 AMG has better materials and more luxury features.

They’re not only potent cruisers but also practical enough for a road trip with the family due to the ample interior space. Headroom and legroom are more than appropriate for taller passengers.

The GLC 43 AMG shines in terms of interior finish. Stepping inside, you’re greeted by premium materials and a well-crafted cabin with typical Mercedes attention to detail. The BMW X3 M40i, despite the significant improvements in its latest LCI iteration, still falls slightly short of the Mercedes in this area.

According to some complaints, the X3 M40i can have noticeable wind noise coming from the front windows, while the GLC 43 AMG has more than expected noise coming from the rear of the SUV.

X3 M40i vs. GLC 43 AMG Reliability

Both SUVs have proven to be reliable since their introduction, with few reported issues.  The BMW X3 M40i might have an edge in long-term reliability. Its robust B58 engine and ZF 8HP transmission have a solid reputation for reliability. A commonly reported issue is the grille shutters malfunctioning and causing a check engine light.

The Mercedes GLC 43 AMG, on the other hand, has some reported complaints regarding rough shifting with the 9-speed AMG transmission. Moreover, while the optional air suspension provides additional adjustment, it could potentially lead to a costly replacement down the line. That said, the engine has no major issues.

Drivetrains on both are reliable with no major issues

Both engines may start needing costly maintenance at high mileage, completely expected from these two high-performance engines. For example, the X3 M40i B58 engine may experience coolant leaks and oil leaks at high mileage. The Bi-turbo M276 DE 30 LA of the GLC 43 AMG may experience high-pressure fuel pump issues.

X3 M40i vs. GLC 43 AMG Price & Value

When considering the price and value, the BMW X3 M40i is a more attractive proposition. The X3 M40i starts at $59,950. On the other hand, the GLC 43 AMG carries a starting price of $69,350.

You could get a well-optioned X3 M40i for a similar price as a base GLC 43 AMG, but the GLC is already filled with interior amenities even at its base starting price. If luxury is a must, then the GLC will be the best option for you.

The value proposition of the X3 M40i is hard to beat

With a lower MSRP, the X3 M40i offers similar performance and features for less money. When similarly equipped, the Mercedes GLC 43 AMG tends to be more expensive than the BMW X3 M40i.

Conclusion & Recommendation

Your choice between the BMW X3 M40i vs. Mercedes GLC 43 AMG should depend on your personal preference. 

For example, if you’re after the utmost in luxury with strong performance, the Mercedes GLC 43 AMG, with its plush interior and elegant, understated styling, might be the better choice for you.

On the other hand, if you’re seeking performance, value for money, and the potential for tuning, the BMW X3 M40i would be the more appealing choice. 

The X3 M40i’s robust engine, well-regarded transmission, and wider aftermarket support provide a good base for any modifications. The intuitive iDrive infotainment system and more aggressive styling may also be more appealing to some.

However, you might find the interior finish and ride comfort slightly less refined compared to the Mercedes, which might be a suitable justification for the price difference.