2009 Honda Fit - Powertrain

Newly developed i-VTEC engine combines outstanding fuel economy with class-topping power

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The new Fit features a new 16-valve, 4-cylinder 1.5-liter SOHC i-VTEC engine that outputs a maximum of 117 hp at 6,600 rpm. It combines enhanced fun-to-drive performance with superior fuel economy and low emissions. Performance is enhanced with the implementation of a more advanced i-VTEC system, larger-diameter intake valves and a resonator chamber in the intake manifold that creates an air-ramming resonance effect for increased torque at low engine speeds and more linear performance. Improvements to coolant flow and piston crown design further contribute to increased low-end torque. Innovations like patterned coating on the piston skirts for improved oil retention and a self-tensioning ancillary drive belt help reduce engine friction for better fuel economy. Environmental performance technologies include an exhaust manifold-integrated cylinder head matched with a high-temperature catalytic converter and high-precision air-fuel ratio control. The 5-speed manual transmission and available 5-speed automatic transmission have also been enhanced for even more efficient power delivery.

• 1.5-liter 16-valve 4-cylinder SOHC i-VTEC engine NEW
• 117 hp @ 6600 rpm and 106 lb-ft @ 4800 rpm
• Estimated EPA fuel economy:
28 mpg city / 35 mpg highway (Fit AT)
27 mpg city / 33 mpg highway (MT / Fit Sport AT)
• CARB EPA-rated emissions: ULEV-2, EPA-rated Tier-2 Bin-5
• i-VTEC low/high-speed intelligent variable valve timing and lift electronic control technology NEW

*Based on 2009 EPA mileage estimates, reflecting new EPA fuel economy methods beginning with 2008 models. Use for comparison purposes only. Do not compare to models before 2008. Your actual mileage will vary depending on how you drive and maintain your vehicle.

• Low-friction engine design
• Composite intake manifold with integrated torque-enhancing resonator chamber NEW
• Drive-by-Wire™ throttle control
• Exhaust-manifold-integrated cylinder head with high-temperature close-coupled catalytic converter
• Standard 5-speed manual transmission
• Available 5-speed automatic transmission
• Steering wheel-mounted paddle shifters on Fit Sport with automatic transmission

The 1.5-liter i-VTEC engine - powerful, torquey performance at all engine speeds

The newly developed 1.5L i-VTEC engine delivers both spirited driving performance and outstanding fuel economy. The two-stage i-VTEC system varies intake valve timing and lift between low- and high-speed settings, while valve overlap is optimized for low, medium and high speeds to achieve a significant improvement in breathing efficiency. The result is power and torque to spare, regardless of engine speed, along with outstanding fuel economy. By comparison, the previous generation's VTEC system effectively deactivated one of the two intake valves per cylinder, creating a swirl effect that enhanced torque below 3400 rpm.

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Performance-enhancing technologies

A 4-valve cylinder head with larger intake valves ensures optimum breathing efficiency, for class-leading maximum output. The engine is also specially tuned to deliver abundant low-end torque.

Larger-diameter intake valves

The 4-valve cylinder head is fitted with larger, 28 mm-diameter intake valves, increasing valve surface area by 4%. This improves intake efficiency, resulting in lower pumping losses and significantly increased maximum output.

Improved coolant flow

The water jacket has been redesigned for improved coolant flow. This helps suppress engine knocking, a major facto determining the amount of torque available at low engine speeds. The current engine design, which employed separate coolant pathways for the cylinder head and engine block, has been replaced by a new design with a single pathway routed first through the engine block, then through the cylinder head. This allows coolant flow to be concentrated for increased cooling efficiency. Improved control of combustion chamber temperatures significantly reduces knocking, allowing the engine to deliver outstanding low-end torque.

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Simulation of coolant flow speed and distribution

Improved piston crown design

Two other factors that influence engine knocking are residual gases and turbulent kinetic energy. Computer simulations analyzing their distributions led to a combustion chamber shape that more effectively suppresses engine knock. The newly designed piston crown is shaped to prevent the formation of knock-inducing conditions. It features a more compact piston crown design with a thicker outer rim to reduce the amount of residual gases. This allows the engine to produce more torque at low engine speeds.

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Intake manifold with torque-enhancing resonator chamber

The intake manifold contains an integrated resonator chamber that takes advantage of the pulse waves from the individual cylinders to produce an air-ramming resonance effect. The capacity and shape of the resonator's chamber and connecting tubes have been tuned to fill in the dip in the i-VTEC engine's torque curve around 3,500 rpm and deliver smoother, more linear driving performance.

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Drive-by-Wire™

Drive-by-Wire™ (DBW) ensures increased response to driver throttle input. The position of the accelerator pedal is translated into an electric signal that is sent to the computer which directly operates the engine's throttle valve.

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High-strength fracture-split connecting rods

The hot-forged, fracture-split connecting rods are made of high-strength steel for 50% greater fatigue resistance. This allows a 17% reduction of the connecting rod cross-sectional area, resulting in a weight reduction - including the crankshaft balance weights - of approximately 2.2 lb. Lighter connecting rods also lower engine inertia, permitting higher engine speeds.

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High-strength fracture-split rocker arms

The L-shaped primary rocker arms are made of a newly developed aluminum-based material that is approximately 20% stronger. The stronger rocker arms permit greater layout freedom, allowing the i-VTEC mechanism to be employed to regulate valve timing and lift between low and high engine speeds. The result is less weight and higher output.


Fuel economy-enhancing technologies

Fuel economy is enhanced through friction reduction and other measures.

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Patterned piston coating - a world's first

The piston skirt has been reshaped and its surface treated to reduce friction and piston slapping noise. The piston skirt also features a patterned coating process - a world's first - which improves oil retention to further reduce friction. Other friction-reduction measures include such important details as more elaborate, high-precision surfacing of the cylinder walls and main crankshaft bearings treated with molybdenum disulfide for optimum oil film retention.

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Self-tensioning ancillary driving belt

The belt driving the ancillaries has a self-tensioning mechanism. It adjusts belt tension according to load. It also helps absorb dynamic variations in belt tension, contributing to a more stable tension. Belt tension can thus be reduced under low loads, helping reduce engine friction losses for further improved fuel efficiency.



Exhaust manifold-integrated cylinder head with newly developed, high-temperature catalytic converter

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The exhaust manifold-integrated cylinder head is combined with a newly developed, close-coupled catalytic converter capable of withstanding higher exhaust temperatures. To this end, the material supporting the catalyst elements inside the catalytic converter unit is now of a highly heat-resistant type to prevent fiber deformation up to significantly higher temperatures. This allows the catalytic converter to operate at up to 40??qC higher temperatures. This contributes to reduced fuel consumption at high vehicle speeds or under heavy engine loads, improving fuel economy in real-world various driving conditions.

Lightweight composite valve cover

The lightweight composite valve cover provides approximately 2.2 lbs. in weight savings compared to an aluminum head cover, further contributing to improved fuel economy.

Environmental performance technologies

The Fit's environmental performance - enhancing technologies have been developed to comply with or exceed all anticipated environmental protection regulations.

Enhanced integration for better environmental performance

In addition to improved fuel efficiency, the exhaust manifold-integrated cylinder head and newly-developed high-temperature close-coupled catalytic converter also contribute to a significant reduction in exhaust emissions. The integration of the exhaust manifold into the engine head allows for the location of the exhaust ports within the cylinder head and brings the catalytic converter that much closer. Like the engine head, the exhaust ports are now made of aluminum for a rapid rise in temperature right after engine start. The exhaust gases reach the closer catalytic converter more quickly, and with less heat loss through radiation, helping the catalytic converter reach its operating temperature more rapidly, for quicker exhaust emissions processing.

High-precision air-fuel ratio control

Along with the implementation of an airflow sensor, the control of the air/fuel ratio has been upgraded, replacing the two oxygen sensor system in the current model with a system combining one LAF (Linear Air-Fuel) sensor and one oxygen sensor. This effectively translates into an even more precise two-stage control of the air/fuel ratio. The result is enhanced emissions processing performance along with reduced requirements for rare metal content within the catalytic converter.

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Transmissions

As with the current model, the new Fit comes with a choice of two transmissions, a standard 5-speed manual and a lightweight 5-speed automatic transmission with steering wheel - mounted paddle shifters (Fit Sport). Both are tuned to provide optimum power transmission from the Fit's high-revving engine and deliver quick smooth response to driver input in all gears.

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Standard 5-speed manual transmission

The Fit's standard 5-speed manual transmission is specially designed to deliver maximum enjoyment of the powerful 1.5-liter i-VTEC engine. The new transmission combines an even more positive shift feel with lower gear ratios that best match the engine's output characteristics, to ensure smooth, powerful acceleration all the way up to highway speeds. Shift and clutch-pedal stroke and weight have also been optimized to further highlight the unique driving pleasure the standard stick shift provides.

Available 5-speed automatic transmission

The Fit is one of the only vehicles in its class to offer a 5-speed automatic transmission, which delivers high-quality driving performance with smooth shift changes and quick response for a more natural feel. The transmission features an advanced shift management and a compact, 3-shaft design with the lowest 1st gear and tallest 5th gear in its class. The active torque converter now locks up at even lower vehicle speeds, further contributing to improved fuel economy.

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Steering wheel-mounted paddle shifters (Fit Sport)

As always, Fit Sport models with the 5-speed automatic transmission are equipped with steering wheel - mounted paddle shifters that allow the driver to execute fast, easy shift changes with the sporty feel of a manual transmission.

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