Mazda PY-VPS Specifications
| Engine Model: Mazda PY-VPS |
| Engine Type: 4-cycle 4-cylinder DOHC 16-valve Dual S-VT liquid-cooled gasoline |
| Total Displacement: 151.8 cu.in (2.49 L) |
| Rated Engine Power: 184-194 Hp (137-145 kW) at 6000 rpm |
| Fuel System Type: Gasoline direct injection |
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The Mazda PY-VPS is a 2.5-liter, naturally aspirated
inline-four gasoline engine belonging to the Skyactiv-G family, a generation of
powerplants developed under Mazda’s Skyactiv Technology suite. Introduced in the
early 2010s, this engine was engineered to deliver a combination of high torque
output, exceptional fuel efficiency, and reduced emissions without reliance on
forced induction or hybrid assist.
It represents a fundamental rethinking of the conventional gasoline engine,
incorporating an ultra-high compression ratio, direct injection, and a
sophisticated valvetrain to achieve thermal efficiency previously associated
with diesel engines.
The PY-VPS employs a dual overhead camshaft (DOHC) valvetrain with four valves
per cylinder and a long-stroke architecture that optimizes combustion efficiency
across the engine speed range. A key innovation is the specially tuned exhaust
manifold with a 4-2-1 configuration, which reduces residual gas in the
combustion chamber to prevent knock while maintaining the high compression
ratio.
The engine utilizes a chain-driven timing system and is constructed entirely
from aluminum alloy, contributing to reduced mass and improved thermal
management. Later iterations of the PY-VPS incorporate cylinder deactivation
technology, further enhancing fuel economy during light-load cruising
conditions.
The PY-VPS is a water-cooled, four-stroke, naturally aspirated gasoline engine
configured for transverse mounting in front-wheel-drive and all-wheel-drive
vehicle architectures. Its design prioritizes high thermal efficiency, broad
torque delivery, and responsiveness across the operating range.
Engine Type: Inline-4, 4-cycle, water-cooled, naturally aspirated.
Displacement: 2,488 cc (151.8 cu.in).
Bore and Stroke: 89.0 mm (3.50 in) x 100.0 mm (3.94 in).
Compression Ratio: 13.0:1 (standard markets).
Compression Ratio: 14.0:1 (high-compression markets).
Valvetrain: DOHC, 16-valve (4 valves per cylinder) with chain drive and Dual
S-VT.
Fuel System: Direct injection (DI).
Firing Order: 1-3-4-2.
Maximum Power: 137-145 kW (184-194 Hp) at 5,700-6,000 rpm.
Maximum Torque: 250-258 Nm (185-190 lb-ft) at 3,250-4,000 rpm.
Idle Speed: 650 ± 50 rpm.
Engine Redline: 6,500 rpm.
The cylinder block is manufactured from aluminum alloy,
a selection that reduces overall engine mass and improves heat dissipation
compared to cast iron alternatives. The block features a closed-deck design at
the upper cylinder region, providing enhanced support for the cylinder head
gasket and minimizing bore distortion under high compression loads. The
deep-skirt block architecture extends the cylinder walls below the crankshaft
centerline, contributing to structural rigidity and reduced noise, vibration,
and harshness (NVH).
Cast-in-place cylinder bores are machined directly into the aluminum block using
a high-precision boring process. A cast iron main bearing support structure is
integrated into the lower block to provide reinforcement for the five main
bearing caps.
The crankshaft is supported by five bearings and is constructed from forged
steel to withstand the elevated cylinder pressures generated by the 13.0:1 and
14.0:1 compression ratios. A structural aluminum oil pan is sealed to the lower
crankcase, contributing to overall engine rigidity and serving as the oil
reservoir.
Block Material: Aluminum alloy.
Bore Diameter (finished): 89.0 mm (3.50 in).
Main Bearing Caps: Cast iron, two-bolt design with integrated
reinforcement structure.
Cylinder Bore Deformation Limit: 0.03 mm (0.0012 in).
The cylinder head is manufactured from aluminum alloy
and incorporates a high-tumble intake port design that promotes aggressive air
movement within the combustion chamber. This tumble flow enhances fuel
atomization and mixing when combined with the direct injection system,
contributing to faster, more stable combustion. The cross-flow design positions
the intake manifold on the firewall side and the exhaust manifold on the front
side on transverse applications.
The DOHC valvetrain actuates sixteen valves - two intake and two exhaust per
cylinder - through a system of roller rocker arms and hydraulic lash adjusters.
Dual S-VT (Sequential Valve Timing) provides independent, continuously variable
control of both intake and exhaust camshaft phasing.
This system allows for precise valve timing adjustment across the engine speed
and load range, optimizing volumetric efficiency, reducing internal exhaust gas
recirculation, and enabling the high compression ratio without knock. The
camshafts are driven by a roller chain from the crankshaft, with an automatic
hydraulic tensioner maintaining chain tension. The engine is of interference
design; the high compression ratio and valve timing range require precise timing
chain integrity.
A long-runner exhaust manifold with a 4-2-1 configuration is integrated into the
cylinder head casting on many variants. This design reduces interference between
exhaust pulses from adjacent cylinders, minimizing residual gas retained in the
combustion chamber and effectively lowering the charge temperature to suppress
knock.
Head Material: Aluminum alloy.
Valve Diameter (Intake): 32.5 mm (1.28 in).
Valve Diameter (Exhaust): 28.0 mm (1.10 in).
Valve Stem Diameter: 5.5 mm (0.22 in).
Valve Seat Angle: 45 degrees.
Valve Configuration: DOHC, 4 valves per cylinder with roller rocker arms and
hydraulic lash adjusters.
Valve Timing Control: Dual S-VT with independent intake and exhaust camshaft
phasing (intake range: 0-60° advance; exhaust range: 0-45° retard).
The PY-VPS employs a direct injection system where fuel
is injected directly into the combustion chamber at high pressure. A
high-pressure fuel pump, driven by a cam lobe on the exhaust camshaft, draws
fuel from the tank and delivers it to a fuel rail at pressures up to 20.0 MPa
(2,900 psi). The rail distributes pressurized fuel to six-hole injectors mounted
centrally in the cylinder head, positioned to deliver a finely atomized spray
pattern directly into the combustion chamber.
The system utilizes multiple injection events per combustion cycle - including
up to three injections during the intake and compression strokes - to optimize
mixture formation, reduce wall-wetting, and suppress knock under high-load
conditions. The engine control unit (ECU) calculates injection parameters based
on inputs from the mass airflow sensor, throttle position sensor, coolant
temperature sensor, crankshaft position sensor, and a wideband oxygen sensor for
precise air-fuel ratio control across all operating conditions.
Injection Type: Direct injection.
Injection Pressure: 20.0 MPa (2,900 psi) maximum.
High-Pressure Pump Type: Single-piston plunger pump, camshaft-driven.
Injector Type: Six-hole solenoid or piezoelectric injectors.
Fuel Cutoff: 6,800 rpm.
Fuel Requirement: 87 octane (Research Octane Number 91) minimum for 13.0:1
compression ratio; 91 octane (Research Octane Number 95) recommended for 14.0:1
compression ratio.
The lubrication system is a fully pressurized, wet-sump
design utilizing a gear-type oil pump mounted to the front of the crankshaft. A
variable-displacement oil pump is incorporated in later variants, adjusting oil
flow based on engine speed and load to reduce parasitic losses and improve fuel
efficiency. The oil pump draws lubricant from the structural aluminum oil pan
through a mesh strainer and circulates it through a full-flow, replaceable oil
filter before entering the main oil gallery.
A pressure relief valve maintains system pressure within operational limits.
Piston cooling oil jets are incorporated to direct a stream of oil toward the
underside of each piston crown, managing thermal loads associated with the high
compression ratio. The lubrication system is designed to accommodate extended
oil change intervals while maintaining protection under the elevated combustion
pressures of the Skyactiv-G architecture.
Oil Type: Synthetic, SAE 0W-20 or 5W-30 (ILSAC GF-5 or GF-6 specifications).
Oil Capacity (with filter): 4.8-5.2 liters (5.1-5.5 US qt) (variant dependent).
Oil Pressure (at 3,000 rpm): 300-450 kPa (43.5-65.3 psi).
Oil Pump Type: Gear-type, crankshaft-driven; variable-displacement on later
variants.
Oil Filter Type: Cartridge-type, replaceable element.
The cooling system is a pressurized, liquid-cooled
design employing a cross-flow aluminum radiator with an electric cooling fan. A
centrifugal-type water pump, driven by the timing chain, circulates coolant
through the engine block, cylinder head, heater core, and oil cooler. A
wax-pellet thermostat regulates coolant flow to maintain optimal operating
temperature, with a bypass circuit that allows the engine to warm rapidly by
circulating coolant only within the engine until the thermostat opens.
The cooling system is designed to manage the thermal load generated by the high
compression ratio and direct injection combustion process. An integrated oil
cooler mounted to the cylinder block maintains oil temperature within
operational limits under sustained high-load conditions.
Coolant Type: Ethylene-glycol based antifreeze with corrosion inhibitors.
Coolant Capacity: 6.5-7.5 liters (6.9-7.9 US qt) (variant dependent).
Thermostat Opening Temperature: 80-85 °C (176-185 °F).
Thermostat Full-Open Temperature: 95 °C (203 °F).
Radiator Cap Pressure: 110-140 kPa (16.0-20.3 psi).
Water Pump Type: Centrifugal, timing chain-driven.
| Intake and Exhaust Systems |
Intake System: Composite plastic intake manifold with
variable intake length functionality on certain applications. The intake system
incorporates an air cleaner housing with a dry-type paper filter element. An
electronically controlled throttle body manages airflow into the engine.
Exhaust System: A 4-2-1 exhaust manifold integrated into the cylinder head
casting on many variants, with individual runners grouping cylinders 1 and 4 and
cylinders 2 and 3 before joining into a single downpipe. The extended runner
length reduces residual gas in the combustion chamber by preventing exhaust
pulse interference. A heated oxygen sensor is mounted upstream of the catalytic
converter, with a downstream sensor monitoring catalyst efficiency.
Direct ignition system with individual pencil-type
ignition coils mounted directly over each spark plug. The system eliminates
spark plug wires and allows for precise ignition timing control on a
per-cylinder basis. The ECU utilizes input from the knock sensor, crankshaft
position sensor, and camshaft position sensors to adjust ignition timing for
optimal power, efficiency, and knock suppression.
Timing Drive: A roller chain drives the camshafts from
the crankshaft sprocket. An automatic hydraulic tensioner maintains chain
tension. The timing chain is designed for the service life of the engine with no
specified replacement interval under normal operating conditions.
Cylinder Deactivation (2018+ variants): Later versions of the PY-VPS incorporate
cylinder deactivation technology. The system deactivates the intake and exhaust
valves of cylinders 1 and 4 under light-load conditions through hydraulically
actuated rocker arm mechanisms. The engine operates as a two-cylinder unit
during deceleration and steady-state cruising, reducing pumping losses and
improving fuel economy by up to 20 percent under these conditions.
Overall Length: 570 mm (22.4 in)
Overall Width: 680 mm (26.8 in)
Overall Height: 680 mm (26.8 in)
Dry Weight (complete engine): 135-140 kg (298-309 lb)
Oil Change Interval: 10,000-16,000 km (6,200-10,000 mi)
depending on market and driving conditions. Oil Filter Change: At every oil
change. Timing Chain Inspection: Inspect for noise and tension at 100,000 km
(60,000 mi) intervals. Engine Coolant Replacement: 120,000 km (75,000 mi) or 10
years; thereafter 60,000 km (37,500 mi) or 5 years. Fuel Filter: Integrated with
fuel pump assembly; no scheduled replacement under normal operating conditions.
Spark Plug Replacement: 120,000 km (75,000 mi). Spark Plug Type: NGK ILKAR7L11
or equivalent (iridium-tipped). Spark Plug Gap: 1.0-1.1 mm (0.039-0.043 in).
Drive Belt (Accessory) Inspection: Every 10,000 km (6,200 mi) for tension,
cracking, and glazing. Air Filter Replacement: 40,000 km (25,000 mi) or as
indicated by inspection.
Cylinder Head Bolts (M10 x 1.25), 1st pass: 25-30 Nm
(18-22 lb-ft).
Cylinder Head Bolts (M10 x 1.25), 2nd pass: 45-50 Nm (33-37 lb-ft).
Main Bearing Cap Bolts (M10 x 1.25): 45-50 Nm (33-37 lb-ft).
Connecting Rod Cap Bolts (M8 x 1.0): 25-28 Nm (18-21 lb-ft).
Camshaft Bearing Cap Bolts (M8 x 1.25): 18-22 Nm (13-16 lb-ft).
Intake Manifold Bolts (M8 x 1.25): 20-25 Nm (15-18 lb-ft).
Exhaust Manifold Nuts (M8 x 1.25): 25-30 Nm (18-22 lb-ft).
Spark Plugs: 18-22 Nm (13-16 lb-ft).
Oil Pan Bolts (M6 x 1.0): 8-10 Nm (71-89 lb-in).
Water Pump Bolts (M6 x 1.0): 8-10 Nm (71-89 lb-in).
Timing Chain Tensioner Bolts (M8 x 1.25): 18-22 Nm (13-16 lb-ft).
Crankshaft Pulley Bolt (M18 x 1.5): 150-160 Nm (111-118 lb-ft).
Flywheel / Drive Plate Bolts (M10 x 1.25): 70-75 Nm (52-55 lb-ft).
The Mazda PY-VPS engine is utilized across a broad
range of Mazda’s passenger vehicle and light truck lineup, spanning multiple
generations and model lines from the early 2010s to the present.
Mazda 3 (BM, BN, BP): 2013-present model years.
Mazda 6 (GJ, GL): 2012-present model years.
Mazda CX-5 (KE, KF): 2013-present model years.
Mazda CX-9 (TC): Naturally aspirated variants in select markets.
Mazda CX-30: 2019-present model years.
Mazda MX-5 Miata: Select market variants with 2.5-liter Skyactiv-G engine.
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