Skip to main content

Mercury® MerCruiser®
4.5L

The Next Generation

Featuring a host of engineering innovations, the 4.5L series establishes new standards for power-to-weight ratio, driver experience, acceleration, durability, and ease of maintenance.

  • HP / kW 250 / 186
  • Maximum RPM (WOT) 4800-5200
  • Engine type V6, 2-valve/cylinder pushrod
  • Displacement (L) 4.5
  • Fuel delivery system Computer controlled Multi-Port Electronic Fuel Injection (MPI)

The specifications displayed here may not be indicative of the entire engine family; click on the “See All Models and Specs” link to view the specs in detail.

See All Models and Specs

Named Top Product by Boating Industry

Named Top Product by Boating Industry

The Mercury Marine 4.5L 200hp sterndrive is a 2015 Boating Industry Top Product of the year.

The winning products were selected based on many factors, including innovation, impact on the industry, and how they advanced their category or created a new category. 

Read More

In 2014, the Mercury MerCruiser 4.5L sterndrive engine was named an Innovation Award Winner at the International Boatbuilders Exhibition & Conference (IBEX).

Built for Marine

Built for Marine

Designing a V-6 block solely for marine use allows Mercury to build the 4.5L with the ultimate protection system, using cast-iron componentry where the engine intersects with seawater, and using corrosion-resistant aluminum and composites everywhere else.

Repower Financing.

Repower Financing.

With Mercury Repower Financing, you can easily power up everything from fishing boats, to runabouts, to cruisers with flexible financing on the engine. You can also choose to finance rigging, gauges, controls and even labor. Mercury Repower Financing offers low rates and low monthly payments to fit a boater’s budget.

Click here for more information and get the performance you want!

Powerful Performer.

Powerful Performer.

Thanks to its new, long-runner scroll intake manifold which draws in more air and converts it into additional torque, the 4.5L delivers a ground-breaking power-to-weight ratio and gives you V-8 power in a V-6 package.

Smooth & Quiet.

Smooth & Quiet.

The 4.5L’s newly designed rear-facing throttle body, anti-whistle throttle plate, engine cover and mounts, lightweight flywheel, fuel-supply module, and structural oil pan all work together to deliver a superior idle, smoothness and low vibration. Resulting in an exceptional driving experience.

Corrosion Protection.

Corrosion Protection.

The MercFusion Paint System creates an outer seal against the elements, while MerCathode® provides automatic protection against galvanic corrosion. For maximum defense against saltwater effects, the SeaCore® industrial hardcoat anodizing system and closed-cooling circuit is available.

Sporty Handling.

Sporty Handling.

The 4.5L comes standard with Adaptive Speed Control, which automatically maintains engine rpm regardless of load or water conditions. The result is increased throttle response and a sporty feel.

Easy to Maintain.

Easy to Maintain.

When service is required, maintenance is a snap with the front-mounted drive lube monitor, color-coded maintenance points – including easy-to-reach oil filter and fill – and “how-to” videos that can be accessed via the QR code on the label.

Specifications

Mercury® MerCruiser®: 4.5L

  • HP / kW
    • 250 / 186
    Maximum RPM (WOT)
    • 4800-5200
    Engine type
    • V6, 2-valve/cylinder pushrod
    Displacement (L)
    • 4.5
    Displacement (CID/L)
    • 275 / 4.5
    Bore and stroke
    • 4.0 x 3.6" / 102 x 92 mm
    Recommended fuel
    • Unleaded Regular 87 Octane Minimum (R+M/2) or 90 RON 10% Ethanol Maximum
    Fuel ethanol tolerance
    • Up to 10%
    Fuel requirement
    • 90 RON 10% Ethanol Maximum
    • Unleaded Regular 87 Octane Minimum (R+M/2)
    Engine control system
    • Mechanical Shifting with Optional SmartCraft DTS
    • Standard SmartCraft with Electronic Throttle Control
    Fuel delivery system
    • Computer controlled Multi-Port Electronic Fuel Injection (MPI)
    Air induction
    • Performance-Tuned Scroll Intake Manifold
    Ignition
    • SmartCraft PCM 112 Digital Inductive
    Alternator amp / Watt
    • 70 amp / 882 watt (Belt-Driven)
    Water drain system
    • Air Actuated "Season Extender" (Bravo)
    • Easy Drain "Season Extender" (Alpha)
    Exhaust system
    • Through prop
    Cooling system
    • Water cooled with thermostat; FWC available as factory option (Alpha) and packaged with SeaCore Drive (Bravo)
    Lubrication system
    • Integrated wet sump
    Recommended oil
    • NMMA Certified FCW 25W-40 Synthetic Blend
    Engine guardian system
    • SmartCraft Engine Guardian
    Dimensions (L x W x H)
    • 28 x 30 x 22" / 696 x 740 x 559 mm
    Weight (engine only)
    • 761 lbs / 345 kg
    Compatible drives
    • Alpha
    • Bravo One
    • Bravo Three
    • Bravo Two
    Print Compare With Other Products
  • HP / kW
    • 200 / 149
    Maximum RPM (WOT)
    • 4400-4800
    Engine type
    • V6, 2-valve/cylinder pushrod
    Displacement (L)
    • 4.5
    Bore and stroke
    • 4.0 x 3.6" / 102 x 92 mm
    Recommended fuel
    • Unleaded Regular 87 Octane Minimum (R+M/2) or 90 RON 10% Ethanol Maximum
    Fuel ethanol tolerance
    • Up to 10%
    Fuel requirement
    • 90 RON 10% Ethanol Maximum
    • Unleaded Regular 87 Octane Minimum (R+M/2)
    Engine control system
    • Mechanical Shifting with Optional SmartCraft DTS
    • Standard SmartCraft with Electronic Throttle Control
    Fuel delivery system
    • Computer controlled Multi-Port Electronic Fuel Injection (MPI)
    Air induction
    • Performance-Tuned Scroll Intake Manifold
    Ignition
    • SmartCraft PCM 112 Digital Inductive
    Alternator amp / Watt
    • 70 amp / 882 watt (Belt-Driven)
    Water drain system
    • Easy Drain "Season Extender"
    Exhaust system
    • Through prop
    Cooling system
    • Water cooled with thermostat; FWC available as factory option
    Lubrication system
    • Integrated wet sump
    Recommended oil
    • NMMA Certified FCW 25W-40 Synthetic Blend
    Engine guardian system
    • SmartCraft Engine Guardian
    Dimensions (L x W x H)
    • 28 x 30 x 22" / 696 x 740 x 559 mm
    Weight (engine only)
    • 761 lbs / 345 kg
    Compatible drives
    • Alpha
    Print Compare With Other Products

Performance Tests

Read the reviews.

Mercury engineering reports and performance data. All available on-line for your review.

BHB - Boat House Bulletin Review
Test Date Engine Boat Prop Type
10/2015 4.5L 200hp ECT Mercury® MerCruiser® Tahoe - 195 Enertia® BHB -
8/2015 4.5L 200hp ECT Mercury® MerCruiser® Chaparral - 21 H2O Black Max® BHB -
3/2015 4.5L 250hp ECT Mercury® MerCruiser® Stingray - 250CS Bravo Three® BHB -
2/2015 4.5L 250hp ECT Mercury® MerCruiser® Sea Ray - 310 Sundancer Bravo Three® BHB -
2/2015 4.5L 250hp ECT Mercury® MerCruiser® Crownline - 294CR Bravo Three® BHB -
10/2014 4.5L 250hp ECT Mercury® MerCruiser® Chaparral - 307 SSX Bravo Three® BHB -
7/2014 4.5L 250hp ECT Mercury® MerCruiser® Larson - LX 205 S Black Max® BHB -
9/2014 4.5L 250hp ECT Mercury® MerCruiser® Cobalt - 220 S Bravo Three® BHB -
9/2014 4.5L 250hp ECT Mercury® MerCruiser® Tracker - Q7 Tahoe Black Max® BHB -
6/2014 4.5L 250hp ECT Mercury® MerCruiser® Sea Ray - 220 Sundeck Bravo Three® BHB -
6/2014 4.5L 250hp ECT Mercury® MerCruiser® South Bay - 524SL TTIO Bravo Three® BHB -
6/2014 4.5L 250hp ECT Mercury® MerCruiser® Sea Ray - 310 Sundancer Bravo Three® BHB -
Test Date: 10/2015
Engine: 4.5L 200hp ECT Mercury® MerCruiser®
Boat: Tahoe - 195
Prop: Enertia®
Type: BHB -
Test Date: 8/2015
Engine: 4.5L 200hp ECT Mercury® MerCruiser®
Boat: Chaparral - 21 H2O
Prop: Black Max®
Type: BHB -
Test Date: 3/2015
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: Stingray - 250CS
Prop: Bravo Three®
Type: BHB -
Test Date: 2/2015
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: Sea Ray - 310 Sundancer
Prop: Bravo Three®
Type: BHB -
Test Date: 2/2015
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: Crownline - 294CR
Prop: Bravo Three®
Type: BHB -
Test Date: 10/2014
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: Chaparral - 307 SSX
Prop: Bravo Three®
Type: BHB -
Test Date: 7/2014
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: Larson - LX 205 S
Prop: Black Max®
Type: BHB -
Test Date: 9/2014
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: Cobalt - 220 S
Prop: Bravo Three®
Type: BHB -
Test Date: 9/2014
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: Tracker - Q7 Tahoe
Prop: Black Max®
Type: BHB -
Test Date: 6/2014
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: Sea Ray - 220 Sundeck
Prop: Bravo Three®
Type: BHB -
Test Date: 6/2014
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: South Bay - 524SL TTIO
Prop: Bravo Three®
Type: BHB -
Test Date: 6/2014
Engine: 4.5L 250hp ECT Mercury® MerCruiser®
Boat: Sea Ray - 310 Sundancer
Prop: Bravo Three®
Type: BHB -

See All Performance Tests

Documents

Buy the Books
Buy the Books

You can order all available Mercury literature online or through any authorized Mercury dealer. Please have your outboard or sterndrive serial number before placing the order.

  • Operation, Maintenance, and Warranty Manuals
  • Parts Manual
  • Service Manual

Purchase a Manual

Scroll to Top