2007 Honda Fit Powertrain

4/1/2006 8:14:08 PM

Overview
The 2007 Honda Fit powertrain is designed to deliver fun-to-drive performance with good fuel economy and low emissions. All Fit models are equipped with a 1.5-liter, SOHC, 16-valve 4-cylinder VTEC gasoline engine that generates 109 horsepower and is available with either a 5-speed manual transmission (standard) or a 5-speed automatic transmission (available). The efficient and compact engine uses Honda's Variable Valve Timing and Lift Electronic Control (VTEC) system to deliver top-of-class performance for the sub-compact segment. And, like all Honda engines, it offers excellent fuel economy and low emissions with an estimated EPA city/highway fuel economy rating on manual transmission models of 33/38 miles per gallon and a Low Emissions Vehicle-2 (LEV-2) rating in California (Tier 2 Bin 5 Federal emissions rating).

Powertrain Highlights

  • 1.5-liter 16-Valve SOHC 4-cylinder VTEC engine
  • 109 hp @ 5800 rpm and 105 lb.-ft @ 4800 rpm
  • Honda-estimated EPA fuel economy of 33 mpg city/38 mpg highway
  • CARB rated LEV-2 emissions, Federal Tier-2 Bin-5
  • Narrow angle intake port design
  • Low-friction engine design
  • Drive-by-Wire throttle control
  • Standard 5-speed manual transmission
  • Available 5-speed automatic transmission (segment exclusive)
  • Steering wheel-mounted paddle shifters on Fit Sport with automatic transmission

Most significantly, Fit features Honda's exclusive VTEC valvetrain technology, a composite intake manifold, and low-friction construction for the rocker arms and engine block. The end result is an engine with good low end torque, high-revving power and a high level of fuel efficiency. Further refinements include the use of electronic drive-by-wire throttle control, which allows for quick and precise delivery of fuel to the engine.

The Fit's engine is mated to either a 5-speed manual transmission (standard) or a 5-speed automatic transmission (available). The 5-speed automatic transmission is a first for the Fit worldwide, and it is a first for the segment. Fit's 5-speed automatic transmission also offers a unique steering-wheel-mounted paddle shifter system on the Fit Sport that enhances the driving experience. In manual mode, the transmission will hold the selected gear until another one is selected.

1.5-Liter 16-valve SOHC VTEC 4-Cylinder Engine
The goal of Fit's 1.5-liter VTEC engine is to optimize the balance between high fuel economy and fun-to-drive performance. Using new SAE net horsepower standards (revised 8/04), the Fit's 4-cylinder engine is rated at 109-horsepower.





The engine displaces 1,497 cc and has a 10.4:1 compression ratio with a bore and stroke measuring 73mm x 89.4 mm. The compact VTEC cylinder head utilizes a narrow, 30-degree design between the intake and exhaust valves, contributing to the engine's overall compact size. The lightweight composite intake manifold is a long runner design that contributes to good low and mid-range torque output. Friction reducing technologies include roller bearing tipped rocker arms, a low friction timing chain tensioner, molybdenum coated piston skirts and an offset crankshaft/connecting rod design. Low emissions are a key trait of every Honda engine, and the Fit employs an oblique flow catalytic converter (increases contact area of exhaust gas inside catalyst), stainless steel exhaust pipes (fast warm up, good heat dissipation and low weight) and a conventional exhaust gas recirculation system (re-routes part of the exhaust gas back into the intake air fuel mixture).




Subcompact Power
.
2007 Fit
2006 Kia Rio **
2006 Scion xA**
2006 Chevrolet Aveo**
2007 Toyota Yaris**
Engine displacement (liters)
1.5
1.6
1.5
1.5
1.5
Horsepower @ RPM (SAE net)
109 hp @ 5800
110 hp @ 6000
103 hp @ 6000
103 hp @ 6000
106 hp @ 6000
Torque @ RPM
105 lb.-ft @ 4800
107 lb.-ft @ 4500
101 lb.-ft. @ 4200
107 lb.-ft. @ 3600
103 lb.-ft @ 4200
Fuel Economy (city/hwy)
33/38 (MT)
31/38 (AT)
31/37 (AT-Sport)
26/34 MT
25/32 AT
32/37 MT
31/38 AT
26/35 MT
24/34 AT
34/40 MT
34/39 AT
Transmissions
5MT or 5AT
5MT or 4AT
5MT or 4AT
5MT or 4AT
5MT or 4AT
*Based on 2007 EPA mileage estimates. Use for comparison purposes only. Acutal mileage may very.
** Specifications based on manufacturers' published information.

VTEC
Part of the balance between efficiency and power is made possible by Honda's VTEC variable valve timing system. In the Fit's 16-valve SOHC engine, the VTEC system employs a two rocker arm design (per cylinder on the intake valves) with friction-reducing roller followers for each pair of intake valves, along with intake cam lobes configured to optimize both low- and high-speed operation. Depending on engine load and rpm, an electronic controller determines which cam profile will be used and exactly how the intake valves will operate (usually around 3,400 rpm).

At low revs, where low lift and shorter duration provide optimal operation, the timing of the two intake valves is staggered and the lift asymmetrically skewed in favor of the primary valve. This helps to create a swirl effect within the combustion chamber that increases the efficiency of the burn process. At higher rpm, a hydraulically actuated spool valve causes a locking pin to engage the secondary rocker arm with the primary one, transitioning the secondary valve into a long-duration mode that increases the volume of air/fuel mixture moving into the combustion chamber. The additional air/fuel mixture helps increase power at high rpms.

Electronic Drive-by-Wire Throttle Control
Typically not found on subcompact entry vehicles, electronic Drive-by-Wire throttle control allows Fit to optimize the throttle aperture when the accelerator pedal is applied. Unlike mechanical throttle control, which relies on a cable linking the accelerator pedal to the throttle, drive-by-wire measures the engine's fuel needs electronically, and Fit's computer ECU instantly determines the optimal throttle opening for the driving situation. The throttle body diameter on the Fit is 50mm.

Transmissions Overview
Two transmissions are offered with the Fit, a standard 5-speed manual and a new, lightweight 5-speed automatic transmission with available steering wheel-mounted paddle shifters (on Fit Sport). Both are designed to optimize the power transfer from Fit's high-revving engine and allow for quick, smooth shifts in all gears.

Gear Ratios
.
5-Speed MT
5-Speed AT
1st
3.462
2.996
2nd
1.870
1.679
3rd
1.321
1.067
4th
0.970
0.756
5th
0.757
0.550
Reverse
3.231
1.957
Final Drive Ratio
4.29
4.56

Standard 5-Speed Manual Transmission
Fit's standard 5-speed manual transmission benefits from short shift strokes, while carbon single-cone synchronizers in first and third gear and double cone synchronizers in second gear minimize shift load and increase durability. In first and third gear, the carbon synchronizers reduce the shift load and enhance durability.

Similarly, the double cone synchros used in second gear also helps reduce shift load and contribute to smoother gear shifts and a precise feel. The shifter, complemented by a large and sporty shift knob, shifts through its gear ratio range to provide quick acceleration in lower gears and high fuel economy in higher gears.

Available 5-Speed Automatic Transmission
Fit is one of the only vehicles in its class to offer a 5-speed automatic transmission. The transmission is designed to work in concert with the drive-by-wire throttle control to provide quick and smooth shifts. The compact transmission employs a Direct Control System that manages the oil flow in Fit's lockup clutch torque converter to minimize shift shock. The lockup clutch control improves Fit's fuel economy by operating in all gears, compared to conventional transmissions that operate torque converter lockup only in a few gears. This is most noticeable during braking from higher speeds when the Direct Control System activates the lockup clutch as the transmission downshifts, maximizing the effect of engine braking and the cut of fuel to the engine during this time.

The lightweight transmission, use of the Direct Control System and the active lockup torque converter help the Fit's automatic transmission models achieve similar fuel economy as its generally more-efficient manual transmission counterparts.

Racing-inspired steering-wheel mounted paddle shifter
Fit Sport models with the automatic transmission are equipped with a paddle shifter system mounted on the steering wheel, allowing drivers to quickly and simply control the shifting of the 5-speed automatic transmission. The steering wheel-mounted paddle shifters offer two standard shifting profiles, "Drive" or "Sport," and allow drivers to manually shift gears up or down. The Fit's Smart Paddle incorporates two buttons on the steering wheel. The button on the left controls downshifts and the button on the right controls upshifts. When the Fit's main shifter is in D, or normal drive mode, the paddle shifter can be used to downshift for increased power on hill climbs or engine braking on descents with the transmission automatically shifting up when conditions return to normal. An indicator within the tachometer of Fit's instrument cluster informs the driver what gear the vehicle is in and blinks when a downshift is unavailable.

In Sport mode (S), however, the driver has more control. The transmission will hold whichever gear is chosen by the driver via the paddle shifter. As opposed to normal driving situations where Fit's transmission would automatically upshift when needed, in Sport mode, the transmission holds the selected gear until it is manually shifted.

Fit Powertrain Trivia

Globally, the Honda Fit (also known in European markets as the Jazz) is available in more than 70 countries with four unique engine configurations and three transmissions. The engine is commonly been called the "L" series among enthusiasts, and those engines include:

  • 1.2-liter, 8-valve, SOHC, i-DSI
  • 1.3-liter, 8-valve, SOHC, i-DSI
  • 1.5-liter, 8-valve, SOHC, i-DSI
  • 1.5-liter, 16-valve, SOHC, VTEC

Not used on the U.S. market Fit, Honda's "intelligent" Dual and Sequential Ignition (i-DSI) system uses two spark plugs per cylinder and can fire the spark plugs separately or at the same time to influence combustion characteristics inside the engine (i-DSI is used on the U.S. Civic Hybrid, however). Three transmissions are available in global markets, and those are a Continuously Variable Transmission (CVT), a 5-speed manual transmission and 5-speed automatic transmission. Honda engineers examined localized market preferences when developing the Fit for the U.S., and chose the most powerful engine in the global lineup - the 1.5-liter 16-valve SOHC VTEC (L15A) - and the most appropriate transmissions - the 5-speed manual and the 5-speed automatic.