451 2007–2015 2nd-gen Fortwo
2007–2015 Smart Fortwo (451, 2nd gen)
Gas (1.0L M132 3-cyl, naturally aspirated or turbo Brabus), RWD, 5-speed Getrag single-clutch automated manual (mta) — plus the rare 451 ED electric variant in 2013–2015
Is this you? If your Smart was sold 2008–2015, has the engine behind the rear seats, and lurches a little at every gear shift, you're in the right place.
About this generation
The 451 is the second-generation Fortwo — the volume Smart in North America, sold in the US from 2008 through 2015 and built in Hambach, France. If you're a new 451 owner in the US or Canada, this is almost certainly the chassis you bought, because it was the only Smart sold here for most of its run. It replaced the 450 Mercedes built before the brand had figured out the formula, and it was replaced by the 453, which finally fixed the transmission.
And we have to talk about the transmission. The 451 uses a Getrag 5-speed single-clutch automated manual — not a torque-converter automatic, not a dual-clutch. It's a manual gearbox with a robot pulling the clutch and shifting for you. It works, but it pauses at every shift in a way that makes the car nod forward. Some owners adapt to it in a week. Others never stop hating it. Lifting off the throttle a beat before each upshift smooths it out a lot, and once you learn that rhythm the car becomes pleasant. But it's not a modern automatic and it never will be. Buy with eyes open.
The good news: the M132 1.0L three-cylinder is a tough little engine, parts are still cheap, and most maintenance is genuinely owner-friendly — oil, filters, spark plugs, brakes, even spark plug coils are easy. The bad news: the M132 has two specific known weaknesses (P0303 cylinder-3 misfire and P0410 secondary air injection) and the clutch actuator is its own ongoing wear item. The famous "three bars" warning on the dash — gear position lost — is the most-Googled 451 problem in the world, and the cheapest first fix is a brake-pedal reteach you can do yourself in five minutes. This page exists to keep you out of the dealer for things you can solve at home.
The 451 is small, the 451 is cheap to keep alive if you stay current, and the 451 is honestly fun in town once you get the rhythm. It's a poor highway car (premium-fuel, screaming at 75 mph, twitchy in crosswinds) and a poor anything-with-cargo car. Buy it for what it is. There's a reason they're still on the road in numbers a decade after the last one rolled off the line.
Quick specs
- Engine options
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- 1.0L M132 3-cylinder naturally aspirated (70 hp / 84 lb-ft) — US-spec base 2008–2015
- 1.0L M132 3-cylinder turbo (Brabus, ~89–101 hp depending on year and market)
- 0.8L CDI diesel 3-cylinder — EU only, never sold in US
- Electric drive (451 ED): 17.6 kWh, ~74 hp, ~68 mi EPA range — US 2013–2015
- Gearbox
- 5-speed Getrag single-clutch automated manual ("mta" — sometimes called softouch or softshift). A real 5-speed manual was a rare option in some markets. NOT a torque-converter automatic and NOT a dual-clutch — there is one clutch and a robot operating it.
- MPG / Range
- 36 city / 38 hwy combined (gas) · ~68 mi EPA range (451 ED)
- Length
- 8 ft 10 in (2,695 mm) — same Tridion safety cell footprint as the 450 and 453
- Weight
- 1,820–1,950 lb (825–885 kg) depending on trim — Cabrio is heavier than coupe
- Fuel
- Premium unleaded (91 octane / 95 RON) — Mercedes-spec, not optional
- Built in
- Hambach, France
- Seats
- 2
- Cargo
- 7.8 ft³ behind the seats, ~12 ft³ with the seatback folded flat
- Safety
- Tridion safety cell, dual front airbags, side curtains, ESP standard, ABS standard
Downloads & resources
The manuals, diagrams, and quick references that ship with this chassis. PDFs open in a new tab; on-site pages are owner-to-owner walkthroughs.
Missing a manual you'd expect to see? Email us — if it exists, we'll add it.
Trims & variants — what each one meant
Smart's trim names look interchangeable across generations, but they mean slightly different things on each chassis. Here's what the labels actually got you on the Fortwo (451, 2nd gen).
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Pure
Base trim, US 2008–2015. Steel wheels, manual A/C, cloth seats, base radio. The 'I just need a Smart' option and the volume seller in the US.
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Pulse
Mid-trim. Alloys, automatic A/C in some years, upgraded interior trim. Coupe and Cabrio body styles.
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Passion
Top trim short of Brabus. Alloys, leather wheel, full panoramic glass roof on the Coupe and a power-folding cloth top on the Cabrio. The 'comfortable Smart' spec for North America.
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Brabus
The factory hot-rod. Turbocharged M132, larger Brabus wheels, body kit, sport exhaust, and sport interior. US Brabus production was tiny — a few hundred units total across all years. If you have one, you have something rare.
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Cabrio (body style, all trims)
Not a trim — a body variant of Pure / Pulse / Passion / Brabus. Power-folding cloth roof with removable rails. The roof slider mechanism is a known wear item. If you bought a Cabrio, factor in eventual roof service.
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Electric Drive (ED)
Third-generation Smart ED, sold in the US 2013–2015 as the only 451 EV. 17.6 kWh battery, ~68 mi EPA range, no transmission to lurch. Coupe and Cabrio. Worth its own paragraph in the FAQ — be cautious buying used.
The first 30 days
If you just bought a Fortwo (451, 2nd gen), this is the order to do things in. Stay ahead of these and you'll save yourself a lot of money.
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Learn to drive the single-clutch transmission
The 451's Getrag 5-speed mta will pause at every upshift unless you help it. Lift off the throttle just before each upshift — the same way you would in a stick shift — and the shift smooths out dramatically. At part throttle on light upshifts, a quarter-second lift is all it takes. Drive in manual mode (paddle or shifter) if the auto pauses bother you; you'll get more control over when it shifts. This is the single biggest quality-of-life change new 451 owners learn, and it's free.
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Do a brake-pedal reteach if you ever see the three-bar warning
If your dashboard shows three flashing bars where the gear indicator should be, the trans has lost its position memory. The cheapest first fix: foot off all pedals, ignition on (not started), press and release the brake pedal slowly five times. Wait 30 seconds. Try to start. This works surprisingly often. Full procedure on [three-bar transmission warning](/problems/three-bar-451-transmission-warning/). If it doesn't clear, you're looking at a clutch actuator teach-in or replacement.
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Confirm fluid levels and quality
Engine oil (Mercedes 229.5 spec, 5W-30 typical), coolant (Mercedes spec, ~5L total), brake fluid (DOT 4), and transmission fluid for the Getrag mta. The trans uses a specific Mercedes-spec fluid — don't substitute. Owners 80k+ mi report smoother shifts after a fluid + clutch actuator service.
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Find the service history
Ask the seller for the maintenance booklet or pull a CARFAX. Watch for missed 10k oil intervals, missing brake fluid flush, and especially missing clutch actuator service. If the prior owner skipped maintenance, you'll inherit the bills. Mercedes-Benz dealers can often pull service records by VIN even years later.
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Register for recall alerts
Plug your VIN into [nhtsa.gov/recalls](https://www.nhtsa.gov/recalls) and into Mercedes-Benz USA's recall lookup. The 451 has had recalls for the power-steering ECU, fuel system, and a couple of body items. Recall repairs are free at any Smart-authorized Mercedes dealer regardless of how many owners back the campaign was issued.
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Find an indie before you need one
Smart left North America in 2019 and the dealer network shrank. Not every Mercedes dealer wants to work on Smarts anymore — some still do, some quietly don't. The independent specialist network on the [Mechanic Directory](/mechanic-directory/) is who keeps these cars on the road. Find your two or three best options on a map before something breaks.
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Read your specific Owner's Manual
It's worth the hour. Especially the dashboard symbols, the maintenance schedule, and the section on driving the mta gearbox — Mercedes actually walks you through the lift-off-the-throttle technique. The Quick Guide PDF is a good starting point in Downloads & Resources above.
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Take a baseline scan
A cheap iCarsoft V4.0 or a Foxwell NT530 reads Smart-specific modules (engine, transmission, ABS, SAM, airbag/SRS) the way a generic OBD2 reader can't. Pull all module faults once, save the report, and you have a starting point to compare against later. Generic OBD code lookups will mislead you on this car — Smart-specific tools are worth the $200.
Join the communities
Smart left North America in 2019. The communities below are how owners keep these cars on the road today — tribal knowledge, shop recommendations, parts swaps. Join two or three and lurk for a week before posting.
Global
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Evilution.co.uk
Forum
The deepest enthusiast-run Smart resource on the web — hundreds of code-by-code DIY breakdowns. UK-based but covers all chassis. The 451 section is especially deep. Worth subscribing.
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smartcarforums.com
Forum
Long-running multi-region forum. Slower than Reddit but the search index is gold for older 451 threads — most of the tribal knowledge for this chassis lives here.
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@SmartCarVideos (this site)
YouTube
670+ curated videos organized by generation and job type — the playlist library that goes with smartcarmanuals.com.
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Evilution YouTube
YouTube
Companion channel to the website. Concise, hands-on, no filler. Heavy on 451 content.
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Smart E.R.
YouTube
Practical owner-friendly tips, repairs, and reviews — heavy on Fortwo across generations.
North America
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Smart Car of America
Forum
The North-American-skewed forum and the single best 451 community on the web. The 451 was the volume US Smart, so the archive here is huge — buying threads, fix-it threads, regional shop recommendations. Start here if you bought a US 451.
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r/smartcar
Reddit
Mixed-region subreddit, but heavily US/Canada owner traffic. Good for quick gut-checks on a problem or sanity-checking a quote.
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Smart Car USA Owners (Facebook)
Facebook
login required — worth it
Login required, worth it. Active US owner group — the largest with 451 owners specifically. State-specific shop recommendations and active selling/buying.
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Smart Car Owners Canada (Facebook)
Facebook
login required — worth it
Login required, worth it. Specifically Canadian — winter tire setups, customs questions, importing from US. Most Canadian 451s came from US imports.
UK & Europe
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smart-club.co.uk
Forum
UK-focused, founded around the early 450s but covers all chassis including the 451. Strong technical archive and a real community of long-time owners.
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Smart Car Owners UK (Facebook)
Facebook
login required — worth it
Login required, worth it. UK indie shop recommendations and Brabus/Cabrio enthusiast posts. Strong on the EU-spec 0.8L CDI diesel — the variant US owners can't get.
Australia
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Smart Car Australia (Facebook)
Facebook
login required — worth it
Login required, worth it. AU-specific imports, RHD parts sources, regional indie shops.
Watch this stuff before you wrench
A handful of videos that'll save you an afternoon — @SmartCarVideos first, then the deep enthusiast channels.
Top maintenance items
The owner-friendly jobs that keep this chassis running. Each card is a deeper guide on this site.
Common problems & what to watch
The things that actually fail on this chassis. Cards link to deep guides with cheap-first checks and parts pricing.
Three-bar warning — gear position lost (the most-Googled 451 problem)
DIY firstDiagnose code →
P0303 cylinder-3 misfire — M132 known weakness
DIY firstDiagnose code →
P0410 secondary air injection — Mercedes published a TSB
ShopDiagnose code →
P0805 clutch actuator — fluid leaks and sensor drift
ShopDiagnose code →
Cabrio roof slider failures — the soft-top sliders crack
DIY firstDiagnose code →
Recalls
Recall repairs are free at any Smart-authorized Mercedes dealer regardless of how many owners back the campaign was issued. Look up your VIN below.
Outside the US?
The NHTSA database only covers US-market Smarts. For other regions:
Buying one? Look at these first.
Known weak points
- The single-clutch transmission (Getrag mta). The 451's transmission is the chassis' defining quirk. It pauses at every upshift, drops gear-position memory occasionally (the famous three-bar warning), and the clutch actuator is a wear item that eventually leaks fluid or drifts on its position sensor. None of this is a defect — it's how the gearbox was designed. The fix for most three-bar warnings is a free brake-pedal reteach you can do in five minutes. Learning to lift off the throttle before upshifts smooths out 90% of the harshness. Budget for one clutch actuator service in your ownership.
- P0303 cylinder-3 misfire on the M132. The most common engine fault on the 451. Coil packs and plugs in cylinder 3 fail more than the other two. Check first: pull the engine cover, swap the cylinder-3 coil with cylinder 1, see if the misfire moves. If yes, replace coil ($30) and plug ($8). If no, look deeper — injector, compression, valve cover sealing. Most 451 owners do this fix at home.
- P0410 secondary air injection failure. The M132 secondary air pump corrodes from condensation, and when it fails the car throws P0410 and won't pass emissions. Mercedes published a TSB on this. The fix is a new pump and sometimes new check valves. Not a DIY job for most — the pump location and the SAM connector are awkward. Budget $400–$700 at an indie shop.
- Clutch actuator wear — P0805 / P2022. The robot that operates the 451's clutch is the most-replaced part on the chassis. Symptoms: harsh shifts that get worse over weeks, three-bar warning that won't clear with a reteach, P0805 or P2022 stored. A teach-in procedure can buy time. Eventually the actuator needs replacement — call it $600–$1,200 depending on whether you reuse the housing.
- Cabrio roof slider failures. On Cabrio body styles, the plastic sliders that guide the soft top along its rails crack and break, and the roof gets stuck mid-cycle or won't seal. Replacement sliders are cheap and the fix is owner-doable on a Saturday. Cosmic Cabrios in the UK is the global authority on these and ships parts internationally.
- Window regulator failures. Both sides eventually. The window slows, then stops, then drops into the door. The plastic regulator clip is the failure point. A complete regulator assembly is $40–$80 and the swap is a 90-minute DIY job. If you have a 451 with original windows past 80k miles, plan for this.
Pre-purchase test drive checklist
- Cold-start the car yourself. The first 60 seconds tell you about misfires, lifters, and exhaust leaks.
- Ask if the three-bar warning has ever appeared. Owners who say "no never" are either lucky or untruthful — most 451s have seen it at least once. The honest answer is more useful than the clean answer.
- Drive a full mixed loop: stop-and-go, 35–50 mph cruise, full-throttle merge onto a highway. Listen for the trans pausing too long, slipping (clutch wear), or shuddering on lift-off.
- On a Cabrio: cycle the roof open and closed at least twice. Listen for the sliders catching. If it pauses, slows, or won't fully cycle, walk away or budget for a slider rebuild.
- Pop the engine cover. Look for oil sheen around the valve cover, around cylinder 3 in particular, and around the secondary air pump. Oil there or visible corrosion on the SAI pump is bad news.
- Ask if the clutch actuator has ever been serviced or replaced. If yes and the receipt is recent, that's a plus. If no and the car is past 100k mi, it's coming.
- Plug in an iCarsoft V4.0 or Foxwell NT530 and pull all modules. Stored history codes — especially P0303, P0410, P0805, P2022 — tell you what the seller cleared.
- Cycle every electrical accessory: windows (both sides — slow windows are pre-failure regulators), mirrors, A/C, all radio functions, both turn signals.
- Check the chassis underneath for rust at the rear subframe and the front Tridion mounts. The Tridion cell is steel, painted, and stays clean — but the subframes and exhaust mounts rust in salt-belt cars.
- Verify the maintenance booklet or pull a CARFAX. Skipped 10k oil intervals are the single biggest predictor of future bills.
Accessories & aftermarket
Pre-filtered searches at the big vendors. We don't take a cut on these clicks today — if you'd rather we did, tell us.
Where to buy parts
Region-by-region. OEM via Mercedes is always available; the alternates below are owner-vetted.
United States
- Mercedes-Benz USA Parts OEM parts via your local Mercedes-Benz dealer parts counter — most can still order Smart parts even if they don't service the cars.
- Pelican Parts (Smart catalog) OEM and quality aftermarket. Fast US shipping; their tech library is genuinely useful for the 451.
- FCP Euro OEM with a lifetime replacement guarantee on most parts. Strong on 451 service items.
- RockAuto Cheapest aftermarket prices; lousy customer service if you get it wrong. Confirm part numbers in the workshop manual first.
United Kingdom
- smartmania.co.uk UK Smart specialist. Genuine + aftermarket. Strong stock for 451 service items.
- Cosmic Cabrios Roof / Cabrio specialist worldwide. The 451 Cabrio slider authority. Will ship internationally.
- Mercedes-Benz UK Parts OEM via UK MB dealer network.
European Union
- AutoDoc Pan-European. Wide aftermarket catalog with EN/DE/FR/IT/ES/NL/PL UI. Strong 451 catalog including the EU-only CDI diesel parts.
- Mister-Auto France-based, ships across EU.
Australia
- Mercedes-Benz Australia Parts OEM via AU MB dealer network.
- Auto Parts Direct (AU) AU-based aftermarket; check Smart catalog availability.
Find a Smart-experienced mechanic
Curated directory of 130+ shops across the US, Canada, UK, and Europe that actually work on Smarts — not just every Mercedes dealer that took the franchise. The map is owner-recommended, vetted before listing, and updated as shops open and close.
Stuck? Ask SmartDiag-AI.
Tell SmartDiag what your Fortwo (451, 2nd gen) is doing — or paste a code. It'll work the cheap-first checks with you, weight likely causes against community-known patterns, and cite the workshop manual for each suggestion. The link below pre-fills your chassis.
Frequently asked questions
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Is this the one with the jerky transmission?
Yes. The 451 uses a Getrag 5-speed single-clutch automated manual — a manual gearbox with a robot operating the clutch and shifting for you. It pauses at every upshift in a way that makes the car nod forward. It's not a defect, it's the design. The 453 that came after it has a real dual-clutch automatic that doesn't do this. -
Can I fix the shifts being so abrupt?
Not really — but you can drive around it. The single biggest improvement is to lift off the throttle a beat before each upshift, the same way you would in a stick shift. The trans then has time to pre-engage the next gear and the shift smooths out. After a week of this it becomes muscle memory. Driving in manual mode (paddle or shifter) gives you more control over when shifts happen. None of this fixes the gearbox, it just makes you better at driving it. -
Does it really need premium gas?
Yes. Mercedes specifies 91 octane (or 95 RON in EU) for the 451's M132 engine, naturally-aspirated and turbo. Running 87 isn't catastrophic but the engine will pull timing and you'll lose 2–4 mpg. Just budget for premium. -
Can I work on a 451 myself?
Most surface jobs — oil, filters, spark plugs, brake pads, cabin filter, window regulators, even Cabrio roof sliders — are owner-friendly on the 451. The harder stuff is the transmission. The clutch actuator can be teach-in'd and serviced at home with patience and the right scan tool, but a full replacement and any deeper work inside the gearbox is a Smart-experienced shop job. The engine sits behind the rear seats under the cargo floor, so any deep engine work means dropping the rear subframe. -
Where do I buy parts in the US?
Most Mercedes-Benz dealers can still order OEM Smart parts via the MB parts catalog — even if they don't service the cars anymore. Pelican Parts and FCP Euro stock 451-specific items and ship fast. RockAuto is cheapest if you know exactly what you need. For Cabrio roof parts specifically, Cosmic Cabrios in the UK is the global specialist and ships internationally. -
Is the 451 ED (electric) worth buying used?
Honestly, only in narrow circumstances. The 17.6 kWh battery and ~68-mile EPA range were already short in 2013; on a 10+ year old example you're looking at 45–55 miles in summer and 30–40 in winter. There's no thermal management on the pack the way modern EVs have, so degradation is harder to predict. Battery replacement is effectively impossible — Mercedes doesn't service them anymore. If your daily round-trip is under 30 miles, you can charge at home, and the car is dirt cheap, it's a fun second car. As a primary vehicle, no. -
Are 451s reliable?
Mostly yes — if you stay on top of the M132 quirks (P0303, P0410), accept that the clutch actuator is a wear item, and learn to drive the trans the way it wants to be driven. There's no exotic engineering here: it's a small Mercedes engine, a Getrag gearbox, and a Tridion cell. Plenty of 451s are past 150k miles and going strong. The cars that get scrapped are the ones whose owners ignored small problems until they became large. -
Will smart come back to North America?
Probably not as the brand you bought. Smart in 2024+ is a Mercedes-Geely joint venture building Tesla-fighter SUVs (the #1 and #3) — completely different cars from the Fortwo you're driving. The original Fortwo line ended production in 2024 and the brand belongs to Geely now. Treat your 451 as a piece of automotive history.