BMW 3 Series trim comparison
2025 BMW 3 Series 330i vs M340i
The 3 Series 330i starts at $45,950 while the M340i is $60,200. That $14,250 gap buys 7 meaningful differences.
This trim jump changes the engine from 2.0L I4 mild-hybrid Turbo to 3.0L I6 mild-hybrid Turbo. Everything else is secondary to whether that powertrain difference matters for how you drive.
If you would notice the 3.0L I6 mild-hybrid Turbo every week, the M340i makes sense. If not, the 330i is the cleaner stop because this jump matters for the powertrain first and the trim badge second.
If you are budgeting this move monthly, the jump from the 330i to the M340i is about $251/month on a 60-month loan at 6.5% APR with 10% down. That works out to roughly $15,060 more by the time interest is counted. If that different powertrain is not part of your real use case, the cheaper trim keeps more money in your pocket without changing the core experience you need.
Lock one trim, change the other side, and move through exact pair pages without resetting back to the full lineup every time.
Who notices the difference
The higher trim starts to make more sense when you are specifically shopping for the stronger powertrain, not just more trim content.
When both feel the same
The 330i and M340i are mechanically identical where it counts: the same 8-speed shiftable automatic transmission and identical wheelbase and body dimensions.
The upgrade math
You are paying $14,250 for 6 measurable differences, which works out to about $2,375 per change.
Key Differences at a Glance
This is the fast read: price, power, efficiency, and the feature flips most likely to change the answer.
Every Difference, Side by Side
This is the full read behind the quick decision signals above: the complete hardware, comfort, and equipment story. 7 specification differences, 1 shared.
Full Specification Comparison
Specifications reflect available data as of early 2025. Confirm details with an authorized dealer before purchasing.
| Spec | 330i | M340i |
|---|---|---|
| Pricing | ||
| MSRP | $45,950 | $60,200 |
| Powertrain | ||
| Engine | 2.0L I4 mild-hybrid Turbo | 3.0L I6 mild-hybrid Turbo |
| Horsepower | 255 hp | 386 hp |
| Torque | 295 lb-ft | 398 lb-ft |
| Transmission | 8-speed shiftable automatic | 8-speed shiftable automatic |
| Drivetrain | RWD | RWD |
| Fuel Economy | ||
| City MPG | 28 | 27 |
| Highway MPG | 35 | 33 |
| Combined MPG | 31 | 29 |
| Fuel Tank | 15.6 gal | 15.6 gal |
| Annual Fuel Cost (EPA) | $1,850/yr | $2,000/yr |
| Dimensions | ||
| Curb Weight | 3,644 lbs | 3,834 lbs |
| Wheelbase | 112.2" | 112.2" |
| Length | 185.9" | 185.9" |
| Width | 71.9" | 71.9" |
| Height | 56.8" | 56.4" |
| Safety | ||
| NHTSA Overall | 5/5 stars | 5/5 stars |
| Warranty | ||
| Bumper-to-Bumper | 4yr/50k | 4yr/50k |
| Powertrain | 4yr/50k | 4yr/50k |
| Corrosion | 12yr/unlimited | 12yr/unlimited |
| Roadside Assistance | 4yr/unlimited | 4yr/unlimited |
Data sources: licensed third-party automotive data, EPA fueleconomy.gov, NHTSA, and official manufacturer materials. Values marked est. are estimated.
2025 BMW 3 Series 330i vs M340i Questions Shoppers Ask
Use this page for the direct trim answer, then zoom back out to the BMW 3 Series lineup, the BMW brand hub, the Compact Cars, the how to pick a trim guide, or our mid-trim value research when you need the bigger shopping path behind this one matchup.
How much more does the 2025 3 Series M340i cost than the 330i?
The M340i starts at $60,200 compared to $45,950 for the 330i. That is a $14,250 difference, or approximately $251/month more on a 60-month loan.
Do the 2025 BMW 3 Series 330i and M340i have the same engine?
No. The 330i uses a 2.0L I4 mild-hybrid Turbo (255 hp, 295 lb-ft), while the M340i has the 3.0L I6 mild-hybrid Turbo (386 hp, 398 lb-ft). That is 131 more horsepower. Both pair with the same 8-speed shiftable automatic.
Do the 2025 3 Series 330i and M340i have the same drivetrain?
Yes. Both come with RWD as standard. The differences between these trims are in features and equipment, not drivetrain.
Is the 2025 3 Series 330i or M340i safer?
Both share the same BMW 3 Series platform with an overall 5-star NHTSA safety rating. Safety ratings are model-level and identical across trims. The trim choice affects comfort and features, not crash protection.
What warranty does the 2025 BMW 3 Series come with?
All 2025 BMW 3 Series trims, including both the 330i and M340i, come with BMW's standard warranty: 4yr/50k bumper-to-bumper and 4yr/50k powertrain coverage. Warranty does not vary by trim level.
Is the 2025 BMW 3 Series M340i worth $14,250 more than the 330i?
The $14,250 buys the 3.0L I6 mild-hybrid Turbo. If that powertrain matters for how you drive, yes. If not, the 330i does the same job for less.
Which 2025 BMW 3 Series trim gets better fuel economy, the 330i or the M340i?
The 330i is the more efficient of the two at 31 combined MPG, versus 29 for the other trim. That matters most if you are balancing running costs against the extra power, drivetrain, or comfort equipment tied to the pricier trim.
The Full Story Behind This Price Gap
Use the direct answer above for this exact matchup, then use these guides to understand whether you are really looking at a feature step-up, a package shuffle, or the point where the lineup starts changing in a meaningful way.
What $14,250 Gets You
At $14,250 more, the 3 Series M340i adds the 3.0L I6 mild-hybrid Turbo engine (+131 hp). This is a situational call. If those features are on your must-have list, the upgrade makes sense. If not, the 330i delivers the same core 3 Series experience for less.
330i vs. M340i: Day-to-Day
The M340i comes with the 3.0L I6 mild-hybrid Turbo instead of the 330i's 2.0L I4 mild-hybrid Turbo. That means 131 more horsepower and 103 more lb-ft of torque. You will notice it most when merging, passing, or climbing at speed. In return, expect about 2 fewer combined MPG.
Fuel Economy Comparison
The 3 Series 330i gets 2 more combined MPG. At $3.50/gallon and 12,000 miles/year, that saves roughly $93 per year or $465 over five years of ownership.
Summary
The 3 Series M340i costs $14,250 more than the 330i (about $251/month more on a 60-month loan). That buys 6 meaningful changes at $2,375 per change. Whether that trade-off is worth it depends on which features matter to your daily driving.
Trim-Matched Accessories
These add-ons are split by trim intent so the recommendations follow the actual use case, not just the same repeated product block.
BMW 3 Series 330i
Value-trim add-onsThese picks fit the 330i best when the goal is covering the daily-use gaps without paying up to the next trim.
BMW 3 Series M340i
Step-up trim add-onsThese picks suit the M340i when you want the accessories to match the nicer cabin, broader utility, or more premium use case.
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Specifications shown combine licensed third-party automotive data with official manufacturer, EPA, and NHTSA source material for the 2025 model year. Actual pricing, features, and availability may vary by region and dealer. Always confirm details with an authorized dealer before making a purchase decision. TrimAtlas is not affiliated with BMW or any dealership.
Page updated 2026-03-18. Verify equipment, pricing, and regional availability with the manufacturer or dealer.