Overview
In keeping with Honda’s mission, to provide both fuel efficiency and fun-to-drive at a high level, the 2015 Fit is powered by an all-new Earth Dreams Technology 1.5-liter engine paired with either a new six-speed manual transmission (6MT) or a new Continuously Variable Transmission (CVT). A program of weight saving, friction reduction, technology application and clever engineering resulted in an 11 percent increase in horsepower to 130, and a 7.5 percent increase in torque to 114 lb-ft over the previous Fit’s engine. A similar approach produced transmissions that help provide quicker acceleration, smoother shifting and class-leading EPA fuel-economy ratings of 29/37/32 (city/highway/combined)1 for manual transmission models, 33/41/36 for the LX trim with CVT and 32/38/35 for the EX and EX-L trims with CVT.
Key New Powertrain Features
- Engine
- i-VTEC® (intelligent Variable Valve Timing and Lift Electronic Control) for intake valves with Variable Timing Control (VTC)
- Computer-controlled direct injection (DI) with multi-hole fuel injectors
- All-plastic intake manifold
- Lower friction
- Reduced weight of moving parts
- Valve diameter increase, decreased plug diameter
- Improved cylinder/piston cooling
- 100,000 +/- miles tune-up interval
- EPA Fuel Economy Ratings (city/highway/combined)1
- 6MT: 29/37/32 mpg
- CVT (LX): 33/41/36 mpg
- CVT (EX, EX-L): 32/38/35 mpg
- Continuously Variable Transmission (CVT)
- New design replaces conventional automatic transmission (design shared with Civic but with Fit-specific tuning)
- Wider ratio range
- High-rigidity belt
- Reduced friction
- Increased torque converter capacity
- Reduced weight and size
- Six-Speed Manual Transmission (6MT)
- New design
- Optimized gear ratios with wider range
- Shorter shift lever stroke with less resistance for improved shift feel
Engine
The Fit’s new Earth Dreams TechnologyTM engine retains the same 1.5-liter displacement as the previous powerplant, but that’s just about the only thing that carries over. Primary amongst the changes, the new engine features direct injection and a DOHC i-VTEC+VTC valvetrain-a first in a subcompact, which replaces the port injection and SOHC i-VTEC valvetrain of the previous engine. A host of other upgrades and refinements were made to optimize combustion, reduce weight and minimize friction to increase both power and fuel efficiency.
The valvetrain of the new engine is upgraded to DOHC with i-VTEC valve operation that includes Variable Timing Control (VTC). At lower engine speeds, the i-VTEC system employs milder cam profiles, creating shorter valve operation and reduced valve lift to deliver robust torque and fuel efficiency. At higher engine speeds, i-VTEC triggers more aggressive cam profiles that produce longer valve operation and greater valve lift for more horsepower. The VTC system assists in this process by adjusting intake cam phasing to retard valve timing at lower engine speeds for better fuel efficiency and advancing timing at higher speeds to increase valve overlap for reduced pumping losses and more power. Both the intake and exhaust valves have a larger diameter for greater airflow capacity. The intake valve size is increased from 28mm to 29mm and the exhaust valves enlarged from 23mm to 25mm.
The enlarged valves sit in a newly designed cylinder head that includes a smaller M12 sparkplug, down from the previous M14. The head also includes direct injection multi-hole fuel injectors with a small diameter bore, an upgrade from the previous engine’s port injection. Higher-pressure direct injection optimizes fuel atomization allowing for more efficient combustion. To provide a high-tumble intake charge that further enhances combustion efficiency, both the intake port and piston crown have special designs. The piston crown’s design also directs the atomized fuel spray from the injector nozzle toward the sparkplug electrodes for more efficient ignition and to prevent fuel depositing on the cylinder walls. The 10 percent higher compression ratio, raised to 11.5:1 from 10.4:1, and improved combustion efficiency contribute to increased torque and improved engine responsiveness.
To further aid responsiveness, the rotating mass of the crankshaft was reduced by 27 percent by using four instead of eight counterweights and the journal diameter was reduced from 50 mm to 46 mm. Additional engine weight savings were obtained by the use of individual main-bearing caps instead of the larger bearing cap structure of the previous engine, and by utilizing an all-composite intake manifold. To manage combustion heat, an oil jet was added to spray cooling oil onto the underside of the piston, which also helps with lubrication. Also, an aluminum sleeve was added above the cylinder sleeve to improve heat transfer from the cylinder block. The effect of all this work is significant: Horsepower and torque are up significantly throughout the rev range, with peak torque arriving 200 rpm earlier than in the previous engine.
Six-Speed Manual Transmission
The all-new six-speed manual transmission (6MT) offers many benefits over the previous Fit’s five-speed unit. The addition of a sixth gear allowed the overall ratio range to be 5 percent wider, providing better fuel efficiency; and the ratios between third and sixth gears are closer for optimized engine performance. The new 6MT’s first gear is 5 percent lower, third gear is 5 percent higher, fifth gear is 11 percent lower and the new sixth gear has the same ratio as the previous fifth gear.
Another benefit of the new transmission is greatly improved shift feel for sportier and easier gear changes. Through component design changes, the stroke of the gear shift lever is shortened 10 percent for quicker, sportier gear changes. This shorter stroke is also accompanied by a significant reduction in shifting effort. Additionally, engineers achieved a 25 percent reduction in shift cable sliding resistance though optimization of the cable-end bushing rigidity. An improved shift lever bracket also aids smooth, positive shifting.
Continuously Variable Transmission with G-design Shift
Available on LX and EX models and standard on the EX-L is a new Continuously Variable Transmission (CVT) tuned specifically for the Fit. While providing greater fuel efficiency, the CVT also delivers more responsive and linear acceleration compared with the previous five-speed automatic (5AT) as well as conventional CVTs. Several aspects of the new CVT assist in this dual benefit.
A new-design torque converter that is thinner but with an increased capacity optimizes the transfer of the engine’s power to the CVT for improved linearity in engine speed relative to throttle application, and it eliminates the excessive engine revving common with conventional CVTs. The new CVT has a 14 percent wider ratio range that allows the engine to operate in a more optimal range for both good performance and improved fuel efficiency under all driving conditions; this is especially felt with reduced engine speeds at higher vehicle speeds. A newly developed high-rigidity drive belt, new CVT fluid allowing reduced pulley pressure on the belt, and a CVT warmer further extend the unit’s efficiency.
Great efforts were also made to minimize size, weight and friction. The oil pressure control unit and stator flange were redesigned for unified functionality and the parking gear was integrated with the output pulley, both of which reduce size and save weight. The CVT case shape is optimized for lighter weight, the input and output pulley shaft diameters are reduced, and the pulley V-body width is narrower. A smaller forward/reverse mechanism with a reduced-diameter ring gear-made with higher strength steel-is used to make the CVT unit more compact. Other weight reductions were realized with a smaller volume of CVT fluid and lighter-weight final shaft, differential and bearings. In total the weight reductions resulted in the CVT being 16 percent lighter than the previous Fit’s 5AT. Lower friction was obtained by using a more optimized oil pump capacity; a baffle plate to reduce oil agitation; and lower friction taper bearing, seal ring and reverse clutch.
G-design Shift Feature
The Fit CVT is designed to provide the optimum gear ratio for the driving conditions, and to offer a more natural driving feel and to eliminate the “rubber-band” feel sometimes associated with CVT transmissions. The new CVT has special “G-design shift” logic that is designed to offer more immediate acceleration response than either conventional automatics or other CVT designs. When abruptly applying power from a steady-state cruising speed, the Fit CVT immediately sends power to the drive wheels while simultaneously adjusting the gear ratio (seamlessly and progressively downshifting) to smoothly bring the engine to its horsepower peak in a linear way.
By comparison, a conventional automatic is slower to respond and loses time making multiple downshifts. Since the automatic transmission has a limited number of separate, discrete ratios, even when fully downshifted, it can only approximate the optimum engine rpm as speed increases. This cuts into acceleration. Compared to other CVT systems, the Fit CVT offers stronger acceleration response with a linear rise in engine rpm. G-design shift logic gives the Fit a more linear, sporty-and ultimately satisfying-driving feel.
Paddle Shifters (EX, EX-L)
On EX and above models, the CVT transmission can be controlled with steering wheel-mounted, dual-mode paddle shifters to provide a more engaging driver experience. D mode is fully automatic; however the paddle shifters can be used to downshift the transmission for greater engine braking for situations such as descending a steep hill. The transmission can also be upshifted in D mode. When the paddle shifters are used in D mode, full automatic operation will resume after a short time. For spirited driving, S mode includes seven ratios and maintains the selected ratio until the driver operates the paddle shifters again. In S mode the system will only shift automatically to prevent over-revving or lugging the engine.
ECO AssistTM (CVT)
All 2015 Fit models include Honda’s ECO Assist™ technology that can help drivers develop driving habits that enhance fuel efficiency by observing the speedometer ECO Assist light response to driving practices. Fuel-saving behaviors like smooth acceleration and braking make the meter glow green. Less fuel-efficient driving habits will cause the meter to glow blue-green, while aggressive starts and stops that consume extra fuel will cause the meter to glow blue. In addition to the ECO Assist™ technology, on CVT models drivers can also engage the green, dash-mounted “ECON” button to further optimize system control of the transmission, engine and other powertrain elements to help conserve additional fuel.
Powertrain Features
1 2015 EPA mileage ratings. Use for comparison purposes only. Your mileage will vary depending on how you drive and maintain your vehicle.
2 LEV3-ULEV125 models as certified by the California Air Resources Board (CARB).
3 Does not apply to fluid and filter changes. Will vary with driving conditions. Please see your Honda dealer for details.