What is the main difference between an agitator and an impeller?

The main difference is that an agitator uses a central post with fins to move clothes through water, while an impeller uses a low-profile disc or cone at the tub bottom to create currents that pull clothes through the wash water.

Which is better for cleaning heavily soiled clothes, an agitator or an impeller? An agitator is better for heavily soiled clothes because its aggressive twisting motion scrubs fabrics more forcefully, whereas an impeller relies on gentler water currents that may require pre-treating tough stains for optimal results. Does an agitator washer cost more to operate than an impeller washer?

Yes, an agitator washer generally costs more to operate because it uses more water and energy to fill a larger tub and drive the mechanical post, while an impeller washer uses less water and shorter cycles to reduce utility bills.

Is an impeller washer safer for delicate fabrics than an agitator washer?

Yes, an impeller washer is safer for delicate fabrics because its low-profile design creates gentle water currents that reduce fabric stress, whereas an agitator's central post can snag, stretch, or tangle fragile items like lingerie and sheer blouses.

Can I use an agitator washer if I have a septic system?

Yes, you can use an agitator washer with a septic system, but an impeller washer is often a better choice because it uses significantly less water per load, which reduces the burden on your septic tank and drain field over time.

What is a common beginner mistake when choosing between an agitator and an impeller?

A common beginner mistake is assuming an agitator always cleans better, but an impeller often outperforms it for everyday loads because modern impeller designs and wash actions effectively target stains while using less water and energy.

Are agitator and impeller parts interchangeable between washing machines?

No, agitator and impeller parts are not interchangeable because they mount to different drive systems and tub configurations, so you must purchase the specific part designed for your washer's brand and model number to ensure proper fit and function.

Which type of washer is better for washing large bulky items like comforters?

An impeller washer is better for large bulky items because its flat profile leaves more usable tub space for items to move freely, whereas an agitator's central post takes up room and can prevent bulky items from being fully submerged and cleaned.

Can I switch my washing machine from an agitator to an impeller without buying a new washer?

No, you cannot switch from an agitator to an impeller without buying a new washer because the tub, motor, and drive mechanism are engineered specifically for one type, so a simple part swap is not possible or safe to attempt.

Does an impeller washer take longer to wash clothes than an agitator washer?

No, an impeller washer typically takes less time to wash clothes because its high-efficiency design uses shorter cycles and less water, while an agitator washer often requires longer cycles to achieve similar cleaning results on heavily soiled items.

Difference Between

Difference Between Agitator and Impeller

Written byNex Virox Team

Editorial Team

Reviewed byVarshal Nirbhavane

Senior SEO & Organic Growth Professional · 5+ years

Published: August 28, 202619 min read

Quick answer

The main difference between Agitator and Impeller is that an agitator uses a central post with fins to move clothes back and forth, while an impeller uses a low-profile disc or cone at the tub’s base to create a gentle water current. Agitator is a top-loading washer mechanism with a central spindle, while Impeller is a rotating hub that pulls clothes through water.

Key takeaways

Core distinction: An agitator uses a central post with fins, while an impeller uses a low-profile disc with vanes.
How each works: Agitators move clothes through water, whereas impellers create a turbulent water current to clean clothes.
Cost and effort: Agitator washers cost less upfront but use more water and energy per load cycle.
Best-fit use case: Impeller washers suit bulky items and large loads, while agitators handle heavily soiled laundry better.
Most common mistake: Buyers choose agitators for gentleness, but impellers are actually the gentler option on fabrics.

Table of Contents18 sections

Difference Between Agitator and Impeller: Comparison Table

Aspect	Agitator	Impeller
Definition	A central shaft with vanes or fins that rotates to move water and clothes inside the wash basket.	A low-profile disc or cone with angled blades mounted on the tub floor to create water currents.
Purpose	Creates vigorous water motion to scrub clothes against each other for heavy-duty cleaning.	Generates gentle, continuous water flow to lift and tumble clothes for fabric care.
Core Mechanism	Rotates back and forth in short arcs, reversing direction repeatedly to agitate the load.	Spins continuously in one direction, producing a vortex that circulates water through fabrics.
Physical Structure	Tall, finned column that rises from the tub center and extends above the wash load.	Flat, low-profile disc or wing-shaped blades that sit flush or near the tub bottom.
Wash Action	Pushes clothes outward and downward against the tub wall and each other.	Draws water and clothes toward the center, then lifts them upward for tumbling.
Water Level	Requires higher water levels to fully submerge the tall central post and load.	Operates effectively with lower water levels, saving several gallons per cycle.
Wash Cycle Time	Typical cycle runs 45 to 70 minutes depending on load size and soil level.	Standard cycle generally completes in 35 to 60 minutes for comparable loads.
Cleaning Power	Delivers aggressive scrubbing action suited for heavily soiled work clothes and stains.	Provides adequate cleaning for everyday laundry but struggles with ground-in dirt.
Fabric Wear	High mechanical action causes more friction, leading to faster wear on delicate items.	Low-impact tumbling reduces fabric stress, extending the life of clothing.
Tangling Tendency	Frequent direction reversals twist clothes together, often requiring untangling after wash.	Continuous circular flow keeps items separated, minimizing knotting and twisting.
Load Capacity	Handles bulky loads well but reduces cleaning effectiveness when overstuffed.	Accommodates larger loads comfortably because clothes move freely in the water.
Energy Consumption	Uses more electricity per cycle due to longer run times and stronger motor demands.	Consumes less energy per load because shorter cycles require less motor work.
Water Consumption	Needs 15 to 25 gallons per load to cover the agitator post and fabrics.	Uses roughly 10 to 18 gallons per load thanks to low-water wash design.
Motor Power	Requires a high-torque motor to drive the heavy post through dense, wet laundry.	Uses a lighter-duty motor since the low-profile disc meets less water resistance.
Spin Speed	Spin speeds typically reach 600 to 800 RPM, leaving clothes moderately damp.	Spin speeds often reach 700 to 1000 RPM, extracting more water from fabrics.
Noise Level	Produces loud sloshing and mechanical clunking as the post reverses direction.	Runs noticeably quieter due to smooth, continuous rotation without abrupt stops.
Vibration	Generates strong shaking forces during wash, especially with unbalanced heavy loads.	Creates less vibration because the rotating disc stays balanced and low to the floor.
Maintenance Needs	Requires periodic cleaning around the post base where lint and debris accumulate.	Needs occasional removal of the disc to clear trapped objects and residue buildup.
Part Replacement	Agitator posts are widely available and simple to replace with basic tools.	Impeller discs are also replaceable but may cost more due to molded blade design.
Safety Risk	Tall moving post poses a pinch hazard for small children reaching into the tub.	Low-profile disc reduces entrapment risk since moving parts stay beneath the waterline.
Compatibility	Fits traditional top-load washers with deep tubs and high water fill options.	Works in modern top-loaders engineered for low-water, high-efficiency operation.
Detergent Type	Works with regular detergent but requires more suds to distribute across the load.	Needs HE detergent specifically to avoid oversudsing in low-water conditions.
Price Range	Found in budget and mid-range washers typically priced from $400 to $800.	Common in mid-range and premium models priced from $600 to $1,200 or more.
Availability	Widely stocked in big-box stores and appliance retailers across North America.	Increasingly common in new models but less available in older budget inventory.
Common Example	Whirlpool top-load washers with a tall center post agitator assembly.	LG and Samsung top-loaders featuring a low-profile impeller plate design.
Typical Users	Families with kids, outdoor workers, and anyone washing heavily soiled items.	Apartment dwellers, fabric-conscious owners, and those washing daily casual wear.
Best For	Stubborn stains, muddy gear, and large bedding that needs intense mechanical scrubbing.	Gentle fabrics, silk, wool, and everyday garments that need minimal wear.
Limitation	Cannot handle oversized comforters well because the post blocks free movement.	Fails on heavily soiled items that require friction-based cleaning action.
Trend Direction	Slowly phased out by manufacturers favoring high-efficiency low-water designs.	Rapidly adopted as the standard in new top-load washer models since 2015.
Best-Fit Scenario	Choose agitator for tough stains, bulky loads, and budget-conscious buyers.	Choose impeller for gentle care, lower utility bills, and quieter operation.

What Is Agitator?

An agitator is a mechanical device that stirs, mixes, or moves a liquid or semi-solid substance inside a container. It creates motion to blend ingredients, suspend particles, or transfer heat. Agitators exist to make mixing faster, more uniform, and more efficient than manual stirring.

Definition of Agitator

An agitator is a rotating or reciprocating component that imparts mechanical energy to a fluid, producing flow patterns that homogenize mixtures, enhance heat transfer, or maintain suspension. Agitators typically feature a central shaft with blades, paddles, or propellers that rotate at controlled speeds to achieve a desired mixing result.

Key Characteristics of Agitator

Characteristic	What It Means in Practice
Central vertical shaft	A single rotating post extends into the tub, driving the mixing action from the center.
Protruding fins or blades	Physical extensions on the shaft catch clothing or fluid to generate mechanical scrubbing motion.
Reciprocating or oscillating motion	The shaft alternates direction or angle to pull items downward and create friction between loads.
High torque output	Delivers strong rotational force to move dense, heavy, or viscous mixtures without stalling.
Direct mechanical contact	Relies on physical contact with the material being mixed, not just fluid currents.
Fixed or variable speed control	Operators can adjust rotation speed to match the sensitivity or thickness of the material.
Simple robust construction	Fewer moving parts than alternative systems, making agitators durable and easy to service.
Wide blade surface area	Larger surface pushes more material per revolution, improving mixing efficiency in large volumes.
Bottom-mount or top-mount design	Installation position varies by tank geometry, but the shaft always penetrates into the process fluid.
Energy-intensive operation	Consumes more power than passive systems because it physically moves the entire load mass.

Common Examples of Agitator

Top-load washing machine agitator – a central finned post that twists back and forth to scrub laundry against itself.
Industrial paint mixer – a shaft-mounted disc or blade that disperses pigments evenly into liquid binders.
Chemical reactor agitator – a turbine-style impeller on a shaft that blends reactants for consistent chemical reactions.
Dairy tank agitator – a slow-turning paddle that keeps milk fat uniformly distributed during storage.
Pharmaceutical blending vessel – a sanitary agitator that homogenizes powders into liquid suspensions without contamination.
Wastewater treatment stirrer – a large vertical agitator that keeps solids suspended in aeration basins.
Food processing kettle – a scraper agitator that prevents soup or sauce from burning on heated walls.
Cosmetic cream mixer – a high-shear agitator that emulsifies oil and water phases into stable lotions.
Concrete mixer drum – a rotating internal agitator that keeps aggregate suspended in wet cement.
Laboratory magnetic stirrer – a small spinning bar that agitates a beaker's contents without external shaft penetration.

Advantages and Limitations of Agitator

Advantages	Limitations
Provides aggressive cleaning action that removes heavy soil and stains from fabric.	Can tangle, snag, or stretch delicate clothing items during the wash cycle.
Handles thick, viscous, or high-solid mixtures that weaker systems cannot move.	Consumes significantly more electricity per cycle compared to low-energy alternatives.
Simple mechanical design is inexpensive to manufacture and repair.	Central post reduces usable tub capacity, limiting how much laundry fits per load.
Works reliably across a wide range of load sizes without losing mixing effectiveness.	Creates mechanical wear on fabrics, shortening the lifespan of frequently washed garments.
Delivers fast mixing times for industrial processes that require quick turnaround.	Produces high noise levels during operation, which can be disruptive in residential settings.
Requires minimal operator training because controls are straightforward.	Cannot handle shear-sensitive materials like certain biological cultures or emulsions.
Effective at suspending dense particles that settle quickly in static fluids.	Creates dead zones near tank walls where mixing is weak or incomplete.
Easily scaled from small laboratory units to massive industrial tanks.	Seals around the rotating shaft can leak, causing maintenance issues or contamination.
Provides consistent, repeatable results for batch processing operations.	Uses more water in washing machines because the agitator needs space to move freely.
Can be customized with different blade shapes for specific mixing applications.	High torque can damage fragile components or overheat when run dry.

What Is Impeller?

An impeller is a rotating component that transfers energy to a fluid, creating flow and mixing. It spins inside a housing to move liquids, gases, or slurries. Impellers exist to generate consistent circulation, shear, and pressure in pumps, mixers, and compressors.

Definition of Impeller

An impeller is a rotating disc or vaned rotor that converts rotational mechanical energy into fluid velocity and pressure. It accelerates fluid outward or axially through centrifugal or axial force, producing directed flow. Engineers use impellers to achieve controlled pumping, mixing, or aeration in industrial systems.

Key Characteristics of Impeller

Characteristic	What It Means in Practice
High-speed rotation	Spins at hundreds to thousands of RPM to generate strong fluid velocity.
Radial or axial flow	Directs fluid either outward from center or along the shaft axis.
Vaned structure	Curved or straight blades that push fluid and create turbulence.
Compact design	Fits inside small housings while delivering high energy transfer.
Low torque requirement	Needs less rotational force than agitators for similar mixing tasks.
Shear generation	Creates intense local shear forces for breaking droplets or particles.
Continuous operation	Runs steadily for long periods without frequent maintenance.
Housing dependence	Performance depends heavily on the surrounding casing or tank geometry.
Wear sensitivity	Prone to erosion or damage when handling abrasive or corrosive media.
Energy efficiency	Converts most input power into useful flow rather than heat or vibration.

Common Examples of Impeller

Centrifugal pump impeller - moves water in residential and municipal systems.
Turbocharger compressor wheel - forces air into engine cylinders for combustion.
Washing machine impeller - creates water currents to clean clothes gently.
Jet ski pump impeller - propels water backward to drive the watercraft forward.
Submersible mixer impeller - keeps solids suspended in wastewater treatment tanks.
Ceiling fan blade assembly - circulates air radially across a room.
Blender cutting blade - spins at high speed to chop and puree food.
Marine propeller - pushes boats through water using axial thrust.
HVAC fan impeller - moves conditioned air through ductwork in buildings.
Chemical reactor impeller - disperses gases into liquid reactants for processing.

Advantages and Limitations of Impeller

Advantages	Limitations
Delivers high flow rates quickly with minimal moving parts.	Cannot handle very viscous fluids without severe efficiency loss.
Produces uniform mixing in low-to-medium viscosity liquids.	Creates dead zones in large tanks where fluid barely moves.
Operates effectively at high rotational speeds for rapid processing.	Cavitation damages the impeller when suction pressure drops too low.
Compact footprint suits tight installations and portable equipment.	Requires precise balancing to avoid vibration and premature bearing failure.
Easy to clean and replace in most pump and mixer designs.	Poor at blending thick pastes or dough-like materials.
Low energy consumption for straightforward pumping duties.	Clogs easily when handling stringy solids or fibrous debris.
Wide material options from plastics to hardened stainless steel.	Performance drops sharply if the housing clearance wears out.
Generates strong shear for emulsifying or homogenizing mixtures.	Excessive shear can damage shear-sensitive biological cells or polymers.
Handles both clean liquids and mildly abrasive slurries.	Cannot reverse direction effectively without losing pumping efficiency.
Produces predictable flow curves for engineering calculations.	Needs a full liquid prime before starting or it runs dry and overheats.

Similarities Between Agitator and Impeller

Shared Aspect	How Agitator and Impeller Are Alike
Core Purpose	Agitator and impeller both move liquid to create flow, mixing, or circulation inside a vessel.
Primary Category	Agitator and impeller are both mechanical mixing components used in fluid processing systems.
Energy Input	Agitator and impeller both require rotational shaft power from an external motor to operate.
Fluid Output	Agitator and impeller both generate fluid velocity and shear within their respective mixing chambers.
Material Build	Agitator and impeller are both commonly fabricated from stainless steel, plastic, or coated metals.
Washing Machines	Agitator and impeller both appear as distinct washing mechanisms in top-load laundry machines.
Industrial Use	Agitator and impeller both mix chemicals, pharmaceuticals, food products, and wastewater in tanks.
Rotation Motion	Agitator and impeller both rely on rotating blades or vanes to disturb and move liquid.
Mixing Goal	Agitator and impeller both aim to achieve uniform consistency of solids, liquids, or gases.
Power Source	Agitator and impeller both connect directly to electric motors through a shaft assembly.
Speed Control	Agitator and impeller both allow variable rotational speeds to adjust mixing intensity for different tasks.
Wear Risk	Agitator and impeller both experience erosion, corrosion, or fatigue from continuous fluid contact.
Maintenance Need	Agitator and impeller both require regular inspection for wear, imbalance, or debris buildup.
Replacement Cost	Agitator and impeller both represent replaceable parts that carry moderate to high procurement expenses.
Installation Method	Agitator and impeller both mount onto a central shaft using fasteners, threads, or keyed fittings.
User Group	Agitator and impeller both serve homeowners and industrial operators who need liquid mixing solutions.
Performance Metric	Agitator and impeller both measure effectiveness by mixing time, uniformity, and energy consumption.
Design Standard	Agitator and impeller both follow engineering guidelines for flow number, power number, and geometry.
Flow Pattern	Agitator and impeller both generate axial or radial flow depending on blade angle and shape.
Load Handling	Agitator and impeller both handle varying liquid viscosities, densities, and solid concentrations.
Operational Risk	Agitator and impeller both risk cavitation, vibration, or shaft bending if operated incorrectly.
Lifespan Expectancy	Agitator and impeller both last several years under normal duty cycles with proper care.
Cleaning Process	Agitator and impeller both require rinsing or wiping to remove residue, lint, or chemical buildup.
Compatibility Factor	Agitator and impeller both must match specific machine models or tank dimensions to function properly.
Energy Efficiency	Agitator and impeller both convert electrical input into useful mixing work with inherent efficiency losses.
Safety Consideration	Agitator and impeller both pose entanglement or pinch hazards when rotating at high speed.
Quality Control	Agitator and impeller both require balanced fabrication to prevent vibration and premature failure.
Application Range	Agitator and impeller both suit small residential units and large-scale industrial reactors alike.
Upgrade Path	Agitator and impeller both offer aftermarket replacements with enhanced materials or optimized blade designs.
Long-Term Outcome	Agitator and impeller both deliver consistent mixing performance when maintained and operated correctly.

Agitator or Impeller: Which Should You Choose?

The single variable that decides it for most people is fabric type. Agitators handle heavy, sturdy fabrics like jeans and towels. Impellers suit delicate items, activewear, and bulky bedding. If you wash mostly cottons and work clothes, choose an agitator. If you wash synthetics or large comforters, choose an impeller.

When to Use Agitator

Choose Agitator when you wash heavily soiled work clothes, denim, or bulky towels that need aggressive scrubbing. It also fits tight budgets, since agitator models cost less upfront. Pick it for large families with tough stains, because the central post drives water through fabric more forcefully than any impeller system.

When to Use Impeller

Choose Impeller when you wash delicate fabrics like silk, lace, or lingerie, or bulky items such as comforters and pillows that tangle around a post. It suits high-efficiency detergents and low water usage goals. Pick it for activewear and stretchy garments, because the low-profile disc prevents snags and fabric damage.

Common Misconceptions About Agitator and Impeller

Common Myth	The Reality
An agitator and an impeller are the exact same part.	An agitator is the entire mixing mechanism, while an impeller is the rotating blade component inside that mechanism.
An impeller only works in a washing machine.	An impeller is a rotating component used in pumps, mixers, and compressors across many industries beyond laundry.
An agitator always has a central post in the washer.	An agitator typically has a central post, but some top-load washers use impeller plates without any post at all.
An impeller is always a flat disc at the bottom.	An impeller can be a flat disc, but it also comes in pitched, curved, and vaned designs for different fluid dynamics.
Agitators and impellers both spin in a full circle continuously.	An agitator twists back and forth, while an impeller rotates continuously in one direction to create flow.
An impeller moves clothes by rubbing them against itself.	An impeller moves clothes by creating a water current that pulls garments through the wash water.
An agitator cleans by spinning clothes around the tub.	An agitator cleans by rotating clothes against each other and the wash water, not by spinning them around.
Impellers are only found in front-load washing machines.	Impellers are common in top-load washers without a center agitator, not just in front-load models.
An agitator is always more powerful than an impeller.	An impeller can be equally powerful for cleaning, relying on water flow rather than mechanical friction.
An impeller cannot handle bulky items like comforters.	An impeller handles bulky items well because it gives them more space to move freely in the tub.
An agitator is gentler on delicate fabrics.	An agitator is harsher on delicates because it physically rubs fabric, while an impeller uses gentler water motion.
Impellers always use less water than agitators.	An impeller uses less water in many models, but water usage depends on the specific washer design and cycle settings.
An agitator is a type of motor, not a separate part.	An agitator is a mechanical component driven by a motor, not the motor itself in any washing machine.
An impeller is just another name for a propeller.	An impeller is similar to a propeller, but an impeller works inside a confined space to move fluid, not free air.
Agitators are obsolete and no longer manufactured.	Agitators are still manufactured and sold widely, especially in budget and traditional top-load washer models.
An impeller cannot get clothes as clean as an agitator.	An impeller cleans effectively with proper detergent and cycle selection, though heavy soil may need extra pretreatment.
An agitator always tangles clothes into a knot.	An agitator can tangle clothes, but modern agitator designs with slower strokes reduce tangling significantly.
An impeller is only used for mixing liquids in chemistry.	An impeller is used in washing machines, pumps, and industrial mixers, not just for chemistry lab applications.
Agitators are always made of metal for durability.	Agitators are often made of molded plastic, which is lightweight, corrosion-resistant, and cheaper to manufacture.
An impeller has no moving parts inside a washer.	An impeller is a moving part that rotates, though it has fewer moving components than a traditional agitator assembly.
An agitator is the same thing as a wash plate.	An agitator is a tall post, while a wash plate is a low-profile disc that functions like an impeller in some washers.
Impellers are too new to have reliability data.	Impellers have been used in washers for decades, with extensive reliability data from major appliance manufacturers.
An agitator cleans by pushing water through the clothes.	An agitator cleans by moving clothes through water, whereas an impeller pushes water through the clothes instead.
An impeller is always quieter than an agitator.	An impeller is often quieter, but noise levels vary by model, motor type, and load balance in the washer.
Agitators require special detergent to work properly.	An agitator works with any standard detergent, though high-efficiency washers with agitators need HE soap.
An impeller cannot be repaired if it breaks.	An impeller can be replaced or repaired by a technician, just like an agitator, with parts available from manufacturers.
An agitator is always taller than an impeller.	An agitator is typically taller, but some impeller designs have raised fins that approach the height of short agitators.
An impeller is only effective with cold water washes.	An impeller works effectively with hot, warm, or cold water, depending on the wash cycle and soil level selected.
Agitators and impellers are interchangeable in any washer.	An agitator and an impeller are not interchangeable because each washer is designed specifically for one mechanism type.
An impeller is a type of agitator, just a smaller version.	An impeller is a distinct mechanism that uses water currents, while an agitator uses mechanical motion to clean clothes.

Conclusion

Difference Between Agitator and Impeller comes down to motion and cleaning. Agitators use a central post with fins, leaving more washroom. Impellers use a low-profile disc, offering gentler fabric care. Choose an agitator for heavy-duty cleaning. Choose an impeller for bulky items and energy efficiency.

FAQs on Difference Between Agitator and Impeller

What is the main difference between an agitator and an impeller?: The main difference is that an agitator uses a central post with fins to move clothes through water, while an impeller uses a low-profile disc or cone at the tub bottom to create currents that pull clothes through the wash water.
Which is better for cleaning heavily soiled clothes, an agitator or an impeller? An agitator is better for heavily soiled clothes because its aggressive twisting motion scrubs fabrics more forcefully, whereas an impeller relies on gentler water currents that may require pre-treating tough stains for optimal results. Does an agitator washer cost more to operate than an impeller washer?: Yes, an agitator washer generally costs more to operate because it uses more water and energy to fill a larger tub and drive the mechanical post, while an impeller washer uses less water and shorter cycles to reduce utility bills.
Is an impeller washer safer for delicate fabrics than an agitator washer?: Yes, an impeller washer is safer for delicate fabrics because its low-profile design creates gentle water currents that reduce fabric stress, whereas an agitator's central post can snag, stretch, or tangle fragile items like lingerie and sheer blouses.
Can I use an agitator washer if I have a septic system?: Yes, you can use an agitator washer with a septic system, but an impeller washer is often a better choice because it uses significantly less water per load, which reduces the burden on your septic tank and drain field over time.
What is a common beginner mistake when choosing between an agitator and an impeller?: A common beginner mistake is assuming an agitator always cleans better, but an impeller often outperforms it for everyday loads because modern impeller designs and wash actions effectively target stains while using less water and energy.
Are agitator and impeller parts interchangeable between washing machines?: No, agitator and impeller parts are not interchangeable because they mount to different drive systems and tub configurations, so you must purchase the specific part designed for your washer's brand and model number to ensure proper fit and function.
Which type of washer is better for washing large bulky items like comforters?: An impeller washer is better for large bulky items because its flat profile leaves more usable tub space for items to move freely, whereas an agitator's central post takes up room and can prevent bulky items from being fully submerged and cleaned.
Can I switch my washing machine from an agitator to an impeller without buying a new washer?: No, you cannot switch from an agitator to an impeller without buying a new washer because the tub, motor, and drive mechanism are engineered specifically for one type, so a simple part swap is not possible or safe to attempt.
Does an impeller washer take longer to wash clothes than an agitator washer?: No, an impeller washer typically takes less time to wash clothes because its high-efficiency design uses shorter cycles and less water, while an agitator washer often requires longer cycles to achieve similar cleaning results on heavily soiled items.