Honda S660: Complete Guide to Honda's Mid Engine Kei Roadster

Overview and History

The Honda S660 is the car Honda fans spent two decades begging for: a modern, turbocharged spiritual successor to the legendary Honda Beat. Produced from April 2015 to March 2022 at Honda's Yokkaichi plant in Mie Prefecture, the S660 carries chassis code JW5 and slots into Honda's storied "S" sports car lineage alongside the S500, S600, S800, and S2000. Where the Beat relied on naturally aspirated revs and an 8,100 RPM redline, the S660 takes the opposite approach: a turbocharged 658cc three cylinder that delivers 75% more torque at a third of the revs. Same mid engine, rear wheel drive formula. Completely different personality.

Honda teased the concept at the 2013 Tokyo Motor Show, and the production version arrived in April 2015 to immediate sellout demand in Japan. The car was designed by Ryo Sugiura, who was only 22 years old when he won Honda's internal design competition to shape the S660. That youth shows in the car's aggressive, modern proportions. It looks nothing like the soft curves of the Beat.

Here is the hard truth for US enthusiasts: the S660 is NOT yet legally importable under the federal 25 year import rule. The earliest 2015 models will not become eligible until 2040. Every S660 you see on US roads right now is either on a show and display exemption, registered as off highway use only, or operating in a legal grey area. So why write about it now? Because the S660 is already commanding serious money on the grey market, prices will only climb as 2040 approaches, and smart buyers are locking in Japanese auction purchases years in advance. If you are new to the world of kei vehicles, our beginner's guide covers the regulations that define this vehicle class.

Honda produced approximately 36,000 S660s across the model's seven year run before Japan's tightening emissions and safety regulations killed it. The final car rolled off the line in March 2022, ending Honda's participation in the kei sports car segment entirely.

Specifications

The S660 is powered by the S07A, a 658cc DOHC turbocharged three cylinder mounted transversely behind the seats. Honda engineered this engine specifically for the S660 platform, tuning it for low end torque rather than the screaming high RPM character of the Beat's E07A. The turbocharger spools quickly thanks to the tiny displacement, delivering peak torque at just 2,600 RPM. That means usable power everywhere in the rev range, not just at the top.

• Engine: 658cc S07A, DOHC 12 valve, turbocharged intercooled
• Power: 63 hp (64 PS) at 6,000 RPM
• Torque: 77 lb-ft (104 Nm) at 2,600 RPM
• Transmission: 6 speed manual or CVT with 7 speed paddle shift simulation
• Drivetrain: Transverse mid engine, rear wheel drive
• Curb weight: 1,830 lbs (830 kg) manual, 1,874 lbs (850 kg) CVT
• Wheelbase: 90.0 inches (2,285 mm)
• Length: 133.7 inches (3,395 mm)
• Width: 58.1 inches (1,475 mm)
• Height: 46.5 inches (1,180 mm)
• Tires: 165/55R15 front, 195/45R16 rear (staggered)
• Fuel tank: 6.6 gallons (25 liters)
• Top speed: 87 mph (140 km/h, electronically limited)
• Fuel economy: ~50 mpg combined (JC08 cycle)
• Turning radius: 15.7 feet (4.8 meters)

The staggered wheel setup, 15 inch fronts and 16 inch rears, is a direct nod to mid engine weight distribution tuning. Honda fitted MacPherson struts up front and an H shaped torsion beam at the rear, keeping the suspension compact enough to fit the tiny footprint while still delivering genuine sports car feedback through the steering wheel. The electric power steering is surprisingly communicative for a kei car.

Both transmissions hit the kei car 63 hp cap, but the driving experience is radically different. The six speed manual is the one to buy. The CVT is adequate for commuting in Tokyo traffic, but it completely dulls the driving character that makes the S660 special. Grassroots Motorsports confirmed this in their drive review: the manual transforms the S660 from a novelty into a genuine driver's car.

The Targa Top Design

The S660 does not have a conventional convertible top or a fixed roof. Instead, Honda designed a roll back targa top that stows in the front trunk. The center section of the roof is a fabric panel that you manually detach, roll up, and tuck into a dedicated compartment under the front hood. It takes about 30 seconds once you get the hang of it.

With the top removed, you get an open air cockpit experience that puts the turbo induction noise and wastegate flutter directly behind your head. Top Gear's review specifically called out this sound as one of the S660's defining characteristics. The rear glass window rolls down independently, so you can get some of that exhaust note without removing the roof panel entirely.

The targa design has practical implications. The front trunk space is tiny even with the top installed. With the rolled up roof panel stowed, you have essentially zero cargo capacity. This is not a car for road trips with luggage. It is a car for driving with nothing but your wallet and your keys.

Honda engineers chose the targa layout over a full convertible for structural rigidity. The S660's body is significantly stiffer than the Beat's, and the fixed rear section and B pillars contribute to a torsional rigidity figure that Honda claimed was comparable to some fixed roof sports cars. You can feel this in corners: the S660 does not flex or shimmy the way many small convertibles do.

Pros and Cons

Pros

• Turbocharged torque changes everything. The S07A delivers 77 lb-ft at just 2,600 RPM, compared to the Beat's 44 lb-ft at 7,000 RPM. You have usable power from idle through redline. No need to wring it out to feel fast. The turbo makes the S660 genuinely quick in its weight class.
• Modern build quality. This is a 2015 and newer Honda. The interior materials, fit and finish, electronics, and NVH refinement are generations ahead of 1990s kei sports cars. The digital instrument cluster, climate control, and optional navigation system make it livable as a daily driver.
• Chassis balance is extraordinary. Mid engine, rear drive, 1,830 lbs, staggered tires, and a wheelbase tuned for rotation. The S660 corners with a precision that embarrasses cars costing five times as much. Honda's engineers clearly prioritized handling over straight line speed.
• Rarity and collectibility. Only about 36,000 built across seven years. Once the 25 year rule opens the floodgates, demand will be massive. Early buyers are positioning themselves for significant appreciation.
• Six speed manual in a modern kei car. Finding a new car with a manual transmission, mid engine layout, turbo, and targa top for under $20,000 (in Japan) is basically impossible outside the S660. Honda gave enthusiasts exactly what they asked for.

Cons

• Not legally importable to the US yet. The earliest 2015 models become eligible in 2040. That is a long wait. Grey market examples exist but carry legal risk and limited registration options.
• CVT models outnumber manuals. The Japanese market heavily favored the CVT, which means finding a six speed manual requires patience and a willingness to pay a premium at auction.
• Virtually zero cargo space. The front trunk is the only storage, and it is barely large enough for a small bag. With the targa top stowed, you have nothing. This is not a practical car by any definition.
• Parts availability outside Japan is poor. The S660 was never sold outside Japan. Every part must be sourced from Japanese suppliers like Amayama or through auction. Crash parts and body panels are especially difficult.
• Still limited to 63 hp. The turbo helps with torque, but the kei car power cap means the S660 is still slow in absolute terms. Highway merging requires planning, and sustained high speed driving is not the car's strength.

Common Modifications

The Japanese aftermarket for the S660 is enormous. Tokyo Auto Salon regularly features dozens of modified S660s. Here are the most popular upgrades:

• Mugen body kit: Mugen's complete aero package includes a front under spoiler, side skirts, rear under spoiler, and a dry carbon rear wing with aluminum mounting. The kit transforms the S660's look from cute to aggressive. Budget ¥300,000 to ¥500,000 ($2,000 to $3,500) for the full set.
• ECU tune / boost controller: While the factory ECU limits output to 63 hp, aftermarket ECU reflashes and boost controllers from HKS and Blitz can push the S07A to 80 to 100 hp. This is the single biggest performance gain available. Budget $500 to $1,500.
• Exhaust system: HKS, Spoon, and Mugen all produce cat back exhausts for the S660. The turbo three cylinder sounds surprisingly good uncorked, with a raspy, aggressive note. Budget $400 to $900.
• Suspension: Cusco, TEIN, and Mugen offer coilover kits. The Modulo X Version Z featured Yamaha Performance Dampers with five step adjustable damping. Aftermarket coilovers run $800 to $1,500.
• Wheels: The factory staggered setup (15/16) opens up a wide range of aftermarket options. RAYS, Enkei, and Work all produce S660 fitments. Mugen's forged staggered wheels are the aspirational choice. Budget $1,200 to $3,000 for a quality set.
• Intake / intercooler upgrade: A larger intercooler and high flow intake improve turbo efficiency and reduce heat soak. Paired with an ECU tune, this is where real power gains happen. Budget $300 to $800.
• Roll bar: Given the targa top design, a roll bar is a smart safety addition for spirited driving. Several Japanese manufacturers produce bolt in options. Budget $400 to $800.
• LED lighting and interior upgrades: Factory headlights are adequate, but LED conversions improve night visibility. Interior upgrades include Mugen's quick shift kit, carbon fiber console trim, and aftermarket bucket seats for taller drivers.

Known Issues and Maintenance Tips

The S660 is fundamentally a Honda, which means the mechanicals are solid. But every car has its weak points. Here is what to watch for:

• CVT longevity concerns: The CVT is the S660's biggest question mark for long term ownership. High mileage CVT units (above 100,000 km) have shown increased failure rates. Fluid changes every 30,000 km are critical. If you are buying used, prioritize the six speed manual or budget $2,000 to $4,000 for a potential CVT replacement.
• Turbocharger maintenance: The small turbo works hard in this application. Oil change intervals matter more on a turbo engine than a naturally aspirated one. Use quality 0W-20 synthetic and change every 5,000 km. Let the engine idle for 30 seconds after hard driving before shutting off to allow the turbo to cool.
• Targa top mechanism wear: The manual roll back top relies on snap fasteners and rubber seals that degrade with UV exposure and age. Inspect seals annually and apply rubber conditioner. Replacement seals are available from Honda Japan but expect a wait.
• Rust on earlier models: While the S660 is newer than most kei imports, cars from snowy regions of Japan (Hokkaido, Tohoku) can already show underbody corrosion. Always check subframes, suspension mounting points, and brake lines. A pre purchase undercoating inspection is worth the cost.
• AC compressor strain: The small engine works hard to power the air conditioning. Compressor failures have been reported on high mileage cars, particularly those driven in hot climates. Listen for unusual noises when the AC engages.
• Clutch wear on manual models: Aggressive driving and improper shifting accelerate clutch wear. The lightweight flywheel and small clutch disc mean replacements come sooner than on a larger car. Budget $500 to $800 for a clutch job if buying a high mileage manual.
• Electrical gremlins on pre facelift models: Some 2015 to 2017 cars have reported minor electrical issues including intermittent dashboard warning lights and infotainment glitches. Honda addressed most of these in the 2018 and later models.

Use Megazip parts diagrams to identify correct JW5 part numbers before ordering from Japan.

Price Guide

The S660 occupies a strange position in the market. In Japan, clean examples sell at auction for ¥1,300,000 to ¥2,500,000 ($9,000 to $17,000). But the moment you add grey market import costs, legal complications, and the scarcity premium of a car that cannot be legally registered in most US states, prices balloon dramatically. Track current market trends on Classic.com.

• Japanese auction (in Japan): ¥1,300,000 to ¥2,500,000 ($9,000 to $17,000) for standard models
• Modulo X and special editions (in Japan): ¥2,500,000 to ¥3,500,000 ($17,000 to $24,000)
• Grey market US (off highway / show and display): $25,000 to $40,000
• Modulo X Version Z (grey market US): $40,000 to $55,000
• Projected 25 year rule pricing (2040+): $15,000 to $30,000 for clean manuals once legal import opens

The six speed manual commands a consistent 15% to 25% premium over equivalent CVT models at Japanese auction. The Modulo X Version Z, limited to the final production year with its Sonic Gray Pearl paint, Bordeaux Red interior, adjustable dampers, and drilled brake rotors, is the most collectible variant and will likely appreciate the most.

Prices will almost certainly rise as 2040 approaches. The S660 benefits from the same hype cycle that drove Suzuki Cappuccino and Autozam AZ-1 prices upward in the years before those cars became import eligible. Smart money is locking in Japanese auction purchases now and storing cars in Japan until the 25 year window opens.

S660 vs Honda Beat: Spiritual Successor

The S660 is the Beat's spiritual successor, but the two cars are more different than they are alike. Hagerty called the S660 "a victory for the littlest guy", and that framing is perfect: both cars prove that driving joy does not require displacement or horsepower.

The Beat is the raw, analog, high revving experience. You have to work the engine hard to extract performance, and that effort is the entire appeal. The S660 is the refined, turbocharged, modern interpretation. Torque is available everywhere, the interior is comfortable, and the build quality is a generation newer.

Which one is better? That depends on what you value. If you want a car you can legally own, drive, and register in the US right now, the Honda Beat is the obvious choice. If you are planning ahead and want the more modern, more powerful, more refined kei sports car experience, the S660 is worth the wait and the premium.

Both cars share the same DNA: mid engine, rear drive, two seats, 660cc, and a commitment to driving joy over straight line speed. Soichiro Honda would have approved of both.

Import Timeline

Every model year becomes eligible for US import exactly 25 years after its date of manufacture. Here is when each S660 production year opens up:

• 2015 models: Eligible starting 2040
• 2016 models: Eligible starting 2041
• 2017 models: Eligible starting 2042
• 2018 models (facelift): Eligible starting 2043
• 2019 models: Eligible starting 2044
• 2020 models: Eligible starting 2045
• 2021 models: Eligible starting 2046
• 2022 models (final year, Modulo X Version Z): Eligible starting 2047

Until those dates arrive, the only legal paths into the US are the NHTSA's show and display exemption (limited to 2,500 miles per year) or off highway use registration in states that allow it. Neither option is ideal for someone who wants to daily drive the car. For a full breakdown of the federal import process, see our complete import guide.

The smartest strategy right now is to purchase an S660 at Japanese auction, where prices are still reasonable, and arrange storage in Japan through your importing broker. You lock in today's prices, avoid the grey market premium, and take delivery when the car becomes legally eligible. Several importers including Japan Car Direct offer long term storage arrangements.

Insurance

Once the S660 becomes legally importable, insurance should be straightforward. Hagerty already insures the Honda Beat and other kei sports cars under agreed value collector policies, and the S660 will almost certainly get the same treatment. For grey market cars on show and display exemptions, Hagerty is currently the most reliable option. Standard carriers will not touch a vehicle without a standard title.

For a detailed breakdown of kei vehicle insurance options, costs, and provider recommendations, see our kei vehicle insurance guide. The r/keitruck community also maintains active discussion threads on which insurers are writing policies in each state.

Where to Buy (Currently)

Buying an S660 from the US requires navigating the grey market or planning for the future. Here are your current options:

• Japanese auctions (buy and store): Browse current S660 inventory on Goo-net Exchange to get a sense of pricing and availability. Work with an auction agent to bid, purchase, and arrange storage in Japan until the 25 year rule opens. This is the smartest long term play.
• Grey market importers: A handful of US dealers bring in S660s for off highway use or show and display. Expect to pay $25,000 to $55,000 depending on spec and condition. Verify the legal basis for the import before purchasing. Do not assume a title means the car is federally legal.
• Private sales: S660s occasionally appear on enthusiast forums, Facebook groups, and specialty platforms like Bring a Trailer. Verify import documentation carefully.
• Direct from Japan: Importers like Duncan Imports and Japanese Classics can source specific S660 configurations through their Japanese networks. Communicate clearly about your intended use case and legal requirements.

Browse our dealer directory to find kei vehicle specialists near you who can assist with sourcing.

The Modulo X Version Z in Sonic Gray Pearl with the six speed manual is the collector's choice. If your goal is maximum appreciation and the most complete driving experience, that is the spec to hunt. Standard Alpha and Beta trim levels in manual are the value play for drivers who care more about the experience than the badge.

Frequently Asked Questions