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Smart · Micro Car · 1998–2007 Custom Search

Smart ForTwo 450

Weaknesses, engine ratings and buying advice

1.0 / 5.0 · Based on 3 engine variants · How we rate
Most Fun Engine

70 PS

Crossblade · Benzin

Madness on wheels

Legendary!
Problem Engine

41–54 PS

0.8L CDI Diesel

4 weaknesses

Stay Away!

Body Variants

The Smart ForTwo 450 is available as Coupé and Convertible — choose your body type for specific insurance data:

Generations


Engine Overview

The Smart ForTwo 450 is available with 4 engine variants — from 41 to 101 hp.

0.8L CDI · Diesel· 41 PS
1999 2006

The smallest production diesel of its time. Fundamentally unsuited to city driving and short trips — precisely the use case of most Smart owners. DPF problems, turbo wear and high repair costs relative to vehicle value make the CDI an engine to avoid. The petrol engines are the far better choice.

  • !! Turbocharger damage from icing in the intake tract from 60,000 km

    On Euro 5 models (54 hp) a sensor was incorrectly positioned. In winter, ice can form in the intake tract and damage the turbocharger. Limp mode activates.

    Symptoms: Engine limp mode in winter, power loss, whistling noises from the turbocharger, engine warning light
    800–2,500 $
  • !! Injectors coked up or faulty from 130,000 km

    The injectors of the OM660 coke up through frequent short-trip use. At 150,000 km and beyond, cold-start problems and rough running appear.

    Symptoms: Poor cold start, rough running, power loss, increased consumption, heavy smoke
    400–1,200 $
  • !! Diesel particulate filter clogged from 80,000 km

    The DPF on the Smart CDI clogs frequently because the vehicle is typically used for short trips. Regeneration requires 20–30 minutes of sustained driving at around 120 km/h.

    Symptoms: Power loss, DPF warning light, increased consumption, engine enters limp mode, regeneration does not complete
    500–1,500 $

+ 1 more engine weaknesses + vehicle weaknesses

0.6L Turbo · Petrol· 45 PS
1998 2006

The Suprex three-cylinder in the first Smart is surprisingly lively for its size thanks to the turbocharger. Fundamentally robust, but the age of these vehicles (20+ years) makes general wear problems unavoidable. The turbo actuator and charge-air hoses are the classic trouble spots.

  • !! Wastegate malfunction from faulty charge-air hoses from 80,000 km

    Porous or cracked charge-air hoses prevent correct wastegate control. The engine goes into limp mode and the turbo is often unnecessarily replaced. This is the most common cause of power loss on the 450.

    Symptoms: Sudden power loss, Smart won't get above 100 km/h, feels throttled, engine warning light illuminated
    5–200 $
  • !! Turbocharger damage from exhaust manifold cracks from 100,000 km

    The exhaust manifold on the 450 has internal dividing walls that can crack and damage the turbocharger. Small cracks in the manifold cause boost pressure loss at full throttle.

    Symptoms: Power loss under full throttle, metallic noises from the engine bay, irregular boost pressure
    700–1,500 $
  • !! Piston ring wear with oil consumption from 120,000 km

    The piston ring grooves in the M160 wear out, allowing oil into the combustion chambers. Burning oil creates carbon deposits on the exhaust valves, which can then burn out.

    Symptoms: Increased oil consumption, blue smoke from exhaust, power loss, carbonised exhaust valves
    800–2,000 $

+ 1 more engine weaknesses + vehicle weaknesses

0.7L Turbo · Petrol· 50–75 PS
1998 2006

The 0.7L version of the Suprex three-cylinder is a development of the 0.6L with more displacement and better torque. In the Roadster it provides adequate driving fun. The known weaknesses of the 0.6L were improved; turbo problems occur less frequently.

  • !! Wastegate linkage corrodes and sticks from 70,000 km

    The ball joint between the actuator and wastegate flap seizes with rust. The flap can no longer open, boost pressure goes unregulated. Engine enters limp mode.

    Symptoms: Engine enters limp mode, no power above 3,500 rpm, engine warning light, feels throttled
    5–100 $
  • !! Turbocharger oil supply blocked from 90,000 km

    The oil feed and return lines to the turbocharger become blocked by carbon sludge. The turbo runs dry and is replaced repeatedly, even though the root cause lies in the oil lines.

    Symptoms: Whistling noises from the turbocharger, power loss, increased oil consumption, turbo failure
    100–800 $
  • !! Excessive oil loss from the engine from 80,000 km

    The M160E7 tends to lose oil from various seals. Regularly flagged at the MOT. Short-trip use makes the problem worse through oil dilution.

    Symptoms: Oil patches under the vehicle, oil smell from engine bay, dropping oil level, MOT advisories for oil leaks
    150–500 $

+ 1 more engine weaknesses + vehicle weaknesses

Crossblade · Petrol· 70 PS
2002 2003

The Suprex three-cylinder in the first Smart is surprisingly lively for its size thanks to the turbocharger. Fundamentally robust, but the age of these vehicles (20+ years) makes general wear problems unavoidable. The turbo actuator and charge-air hoses are the classic trouble spots.

  • !! Wastegate malfunction from faulty charge-air hoses from 80,000 km

    Porous or cracked charge-air hoses prevent correct wastegate control. The engine goes into limp mode and the turbo is often unnecessarily replaced. This is the most common cause of power loss on the 450.

    Symptoms: Sudden power loss, Smart won't get above 100 km/h, feels throttled, engine warning light illuminated
    5–200 $
  • !! Turbocharger damage from exhaust manifold cracks from 100,000 km

    The exhaust manifold on the 450 has internal dividing walls that can crack and damage the turbocharger. Small cracks in the manifold cause boost pressure loss at full throttle.

    Symptoms: Power loss under full throttle, metallic noises from the engine bay, irregular boost pressure
    700–1,500 $
  • !! Piston ring wear with oil consumption from 120,000 km

    The piston ring grooves in the M160 wear out, allowing oil into the combustion chambers. Burning oil creates carbon deposits on the exhaust valves, which can then burn out.

    Symptoms: Increased oil consumption, blue smoke from exhaust, power loss, carbonised exhaust valves
    800–2,000 $

+ 1 more engine weaknesses + vehicle weaknesses

Vehicle Weaknesses

WeaknessCost
Softtouch Clutch Actuator Fails

The electric clutch actuator gets dirty or fails mechanically. Typical pattern: violent jerk on pull-away, gear cannot be selected, display shows 'N'. Problem often from 80,000 km, sometimes temporarily clears after a short stop.

Symptoms: Hard jerk on pull-away, gearbox does not engage, N shown on display, vehicle not driveable
from 85,000 km
Medium
!Softtouch Gearbox Jerks When Shifting

The semi-automatic Softtouch gearbox shifts with noticeable jerks, especially on pull-away and when changing from 3rd to 4th gear. A long shift pause is normal, but excessive jerking indicates a worn clutch or faulty adaptation.

Symptoms: Strong jerk on gearchange, long shift pauses, unsmooth pull-away
from 70,000 km
Medium

Test Reports

pannenstatistik

ADAC Pannenstatistik 2022

Average

Smart ForTwo 450 shows above-average breakdown frequency, largely due to the high age of these vehicles. Ignition system, starter motor and gearbox actuator are the most common failure points.

2022-06
tuev

AUTO BILD TÜV-Report 2025

Average

The Smart ForTwo 450 presents a mixed picture at the MOT. Oil leaks from the drivetrain and corroded exhausts are typical findings. Engine management electronics are considered failure-prone.

2024-11
NHTSA Owner Complaints
Above average
2 complaints · 1998–2007
  1. 01 Engine & Cooling
    1
  2. 02 Fuel System
    1
  3. 03 Gasoline
    1
  4. 04 Airbags
    1
  5. 05 Other
    1

Top Reported Issues

Engine & Cooling (1 complaints)
Fuel System (1 complaints)
Gasoline (1 complaints)
Source: NHTSA (nhtsa.gov) · 2026-03

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Known Problems and Issues +

A total of 26 weaknesses have been documented for the Smart ForTwo 450 (1998–2007) — 12 engine-related and 14 vehicle-related. 3 problem engines: M160E6 (0.6L Turbo), M160E7 (0.7L Turbo), OM660 (0.8L CDI). Typical issues affect Gearbox, Electronics, Body, Rust.

ForTwo (OM660, 1999–2006) — Stay Away!: Turbocharger damage from icing in the intake tract, Injectors coked up or faulty, Diesel particulate filter clogged. Power: 41 PS.

ForTwo (M160E6, 1998–2006) — Stay Away!: Wastegate malfunction from faulty charge-air hoses, Turbocharger damage from exhaust manifold cracks, Piston ring wear with oil consumption. Power: 45 PS.

ForTwo (M160E7, 1998–2006) — Stay Away!: Wastegate linkage corrodes and sticks, Turbocharger oil supply blocked, Excessive oil loss from the engine. Power: 50 PS.

ForTwo (M160E7, 1999–2006) — Stay Away!: Wastegate linkage corrodes and sticks, Turbocharger oil supply blocked, Excessive oil loss from the engine. Power: 61 PS.

ForTwo (M160E7, 1999–2006) — Stay Away!: Wastegate linkage corrodes and sticks, Turbocharger oil supply blocked, Excessive oil loss from the engine. Power: 75 PS.

ForTwo (M160E6, 2002–2003) — Stay Away!: Wastegate malfunction from faulty charge-air hoses, Turbocharger damage from exhaust manifold cracks, Piston ring wear with oil consumption. Power: 70 PS.

What to watch out for with the Smart ForTwo? See the detailed listing of all engine and vehicle weaknesses in the sections above.

Frequently Asked Questions

What problems and weaknesses does the Smart ForTwo 450 have? +
The Smart ForTwo 450 has 12 known engine weaknesses and 14 vehicle weaknesses.
What should I look for when buying a used Smart ForTwo 450? +
faq.watch_a_avoid
Which engine is recommended? +
None of the available engines are rated 'Good Choice'. Stay away! The most fun to drive is the M160E6 (0.6L Turbo). Problem engine: OM660 (0.8L CDI) — stay away!
Which Smart ForTwo 450 engine is the most fun? +
The {code} ({displacement}) offers the most driving fun in the Smart ForTwo 450 — rated: "Legendary!". {description} No roof, no doors, no windscreen — the Crossblade is the craziest Smart ever made. 70 hp is enough when the wind is blasting you in the face.
Is the Smart ForTwo 450 worth buying used? +
Caution is advised with the Smart ForTwo 450 — 3 of 3 engine variants are rated 'Stay Away!'. The engine choice is crucial.
What horsepower variants are available for the Smart ForTwo 450? +
The Smart ForTwo 450 is available with engine variants from 41 to 101 hp. Petrol: M160E6 (0.6L Turbo), M160E7 (0.7L Turbo). Diesel: OM660 (0.8L CDI).

Last updated: February 2026 · All information without guarantee