STIHL RM 448.3 V 18" Petrol Lawn Mower
STIHL RM 448.3 V 18" Petrol Lawn Mower Original price was: £699.00.Current price is: £619.00. inc. VAT
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STIHL SH 56 Blower & Vacuum Shredder Original price was: £399.00.Current price is: £339.00. inc. VAT

STIHL RM 453.3 V 21″ Petrol Lawn Mower

Original price was: £779.00.Current price is: £649.00. inc. VAT

The STIHL RM 453.3 V petrol lawn mower brings exceptional versatility to medium and large gardens. With a wide 21″ cut and Vario self-propulsion, it adapts to your pace and lawn conditions effortlessly.

In Stock
Description

Why buy the STIHL RM 453.3 V 21″ Petrol Lawn Mower?

  • Petrol lawn mower with a wide 51 cm (21″) cutting width.
  • Vario self-drive allows for adjustable mowing speed from 2.4 to 4.2 km/h.
  • Versatile 4-in-1 function: Cut & Collect, Cut & Drop, Side Discharge, and Mulching.
  • Robust yet lightweight polymer deck is rust-proof and UV-resistant.
  • Comfort mono-handlebar for easy grass box access and compact storage.
  • Large 55-litre grass catcher box with integrated fill-level indicator.

Versatile and Powerful Petrol Mower for Large Lawns

The STIHL RM 453.3 V is a highly capable self-propelled petrol lawn mower from STIHL’s 4 Series range, engineered for homeowners tackling medium to large, challenging gardens. Its blend of power, convenience, and versatility makes it an excellent choice for maintaining lawns up to 1200m² on a single tank, with the capacity to handle up to 1800m² under optimal conditions.

Advanced 4-in-1 Mowing System

This mower offers exceptional flexibility with its four distinct mowing methods, which can be changed without needing any additional tools. You can choose the best option for your lawn’s condition and desired finish:

  • Cut & Collect: The standard method using the 55-litre grass catcher for a clean, tidy finish.
  • Cut & Drop: Simply remove the grass box to have the clippings discharged directly behind the mower.
  • Side Discharge: An integrated flap allows clippings to be neatly ejected to the side, ideal for longer grass.
  • Mulching: Using the multi-blade and mulching attachment, grass is finely shredded and returned to the lawn, acting as a natural fertiliser.

Engineered for Durability and Ease of Use

The RM 453.3 V is built upon a rugged polymer deck that is not only lightweight but also rust-proof, petrol-resistant, and double-layered for extra stability. Power is delivered by a reliable STIHL EVC 300 engine, featuring an easy-start system for minimal effort whether the engine is cold or warm. The Vario self-drive allows you to adjust the forward speed to perfectly match your walking pace and the terrain. Smooth-running wheels enhance manoeuvrability and control, ensuring a comfortable mowing experience.

Ergonomic Design for Operator Comfort

STIHL has integrated several features focused on operator comfort. The innovative comfort mono-handlebar provides unrestricted access to the 55-litre grass catcher box, which includes a fill-level indicator and is designed for easy opening and emptying. The super-soft handle grip absorbs vibrations to protect the user’s arms. For storage, the Quick-Fix quick-release tensioners allow the handlebar to be folded down compactly without tools. A central, spring-loaded lever makes adjusting the cutting height simple, with a range from a low 20mm up to 100mm.

As an established STIHL authorised dealer in the UK, Sims Garden Machinery offers more than just a machine in a box. With a history stretching back over a century, the team provides expert guidance and complete aftersales support. The trained sales staff at the Stratford-upon-Avon showroom can help you choose the perfect mower, while the on-site workshop with its team of trained mechanics ensures your investment is supported for years to come. For local customers, this machine includes a free Pre-Delivery Inspection (PDI), personal delivery, and a full handover demonstration to ensure you are confident and ready to mow.

Not sure which machine or part is right for you?
Our team is here to help. Contact us today for expert advice.

Technical Specification

Displacement 166 cm³
Drive Speed 2.4 – 4.2 km/h
Motor Type EVC 300.1
CO2 922 g/kWh
Device Weight 33 kg
Max. Lawn Area 1800 m²
Cutting Width 51 cm
Cutting Height 20 – 100 mm
Rated Engine Speed 2800 r/min
Grass Catcher Box Volume 55 l
Device Width 57 cm
Max. Device Height 108 cm
Front Wheel Diameter 190 mm
Rear Wheel Diameter 215 mm
Measured Sound Pressure Level LpA 82 dB(A)
Guaranteed Sound Power Level LWA 97 dB(A)
Uncertainty Factor KpA 2 dB(A)
Vibration Guide Bar ahw 4.40 m/s²
Vibration Uncertainty K 2.20 m/s²

Why buy from Sims Garden Machinery?

Authorised Dealer

Authorised main dealer

We are authorised dealers for leading brands, meaning genuine parts, manufacturer-approved training, and warranty support you can rely on.

Real People

Real people, real support

No call centres. No ticket systems. Just a knowledgeable local team you can speak to when you need help.

Expert Advice

Expert advice — not pushy sales

Our team are trained mechanics and product specialists, so you get honest, practical advice based on how you’ll actually use the machine.

Since 1908

Established, independent family business

We’re a long-standing independent dealer with deep roots in the local area — built on reputation, repeat customers, and word of mouth.

Frequently Asked Questions

Frequently Asked Questions

What size lawn is the STIHL RM 453.3 V suitable for?

The STIHL RM 453.3 V is specifically designed for medium to large domestic lawns. STIHL states it can comfortably mow lawns up to 1200 m² on a single tank of fuel, and is capable of handling areas up to a maximum of 1800 m² under ideal conditions.

What mowing options does this mower offer?

The RM 453.3 V is a versatile 4-in-1 mower. It can be used for standard cutting and collection with the 55-litre grass box, cutting and dropping (rear discharge), side discharge using the integrated flap for longer grass, or mulching with the included multi-blade and attachment to naturally fertilise your lawn.

Is the mowing speed adjustable?

Yes, it features STIHL’s Vario self-drive system. The mowing speed can be smoothly and infinitely adjusted between 2.4 and 4.2 km/h using a control lever on the handlebar, allowing you to match the pace to your comfort and the lawn’s condition.

How is the cutting height adjusted on the RM 453.3 V?

This mower features a central, single-point cutting height adjustment system. A single spring-loaded lever allows you to easily change the height across a wide range, from 20 mm for a close cut up to 100 mm for longer grass.

User Manuals / Downloads


View STIHL Brochure

Additional information
Dimensions120 × 60 × 62 cm
Brand
Engine SizeThe displacement of the engine in cubic centimetres (cc).166
Blade Brake ClutchIndicates if the blade can be stopped while the engine keeps running.FALSE
Collector SizeThe capacity of the grass collection bag or box in litres.55
Cutting MethodThe cutting mechanism used (e.g., Rotary or Cylinder).Rotary
Cutting WidthThe width of the grass cut in a single pass.51 cm
Deck MaterialThe material the cutter deck is constructed from (e.g., Steel, Aluminium).Polymer
Drive TypeHow the mower is propelled (e.g., Push, Self-Propelled, Variable Speed).Variable Speed
Electric StartIndicates if the machine features a key or push-button electric starter.FALSE
Mowing FunctionsAvailable mowing modes (e.g., Collection, Mulching, Side-Discharge).[“Collection”,”Mulch”,”Side-Discharge”]
Rear RollerIndicates if the mower features a rear roller for creating lawn stripes.FALSE
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About STIHL
We stock a wide range of STIHL garden tools at Sims Garden Machinery. STIHL is an industry renowned garden machine company, producing a wide range of lawnmowers, with both petrol and electric engines. STIHL lawnmowers are available in both push and self-propelling models. STIHL also produces heavy-duty chainsaws, hedge trimmers, and brushcutters, perfect for professional work. We also sell a range of STIHL leaf blowers, with both handheld and backpack models available. There is also a selection of STIHL clothing and accessories, including protective helmets and boots. Our range of STIHL garden tools can be delivered across the UK. If you have ordered gardening equipment, such as a lawnmower or chainsaw, a member of our team will assemble and demonstrate it for you upon delivery.
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Shipping & Delivery

FREE PDI, DELIVERY & HANDOVER

We offer a free delivery service for all machines within a 30 mile radius. Not only that; we build, inspect and run up every machine prior to delivery. Making sure you get a fully functional machine that is set-up and ready for use. On delivery we will run through with you any instructions & maintenance advice so you are comfortable with your new machine.

NATIONAL DELIVERY

  • Each machine will be tested prior to delivery.
  • Orders will be sent out via either ThePalletNetwork or DHL insured service.