Isuzu's third-generation one-tonne pickup, on sale in Europe from December 2020 in Germany and Austria and from March 2021 in the UK, with a single engine: the 1.9-litre RZ4E-TC diesel with 163 hp and 360 Nm, a six-speed manual or an optional six-speed Aisin automatic. Most European trucks have selectable four-wheel drive with low range and, on most trims, a rear differential lock, but the range also included a rear-wheel-drive 4x2 Single Cab. It is a working vehicle first, with a ladder frame, rear leaf springs and roughly 1,100 kg of payload, sold mainly to trades, farms and fleets through a small European dealer network. Isuzu Germany rates the four-wheel-drive versions at 3,500 kg braked towing and the 4x2 Single Cab at 2,500 kg. Isuzu replaced the 1.9 with a larger 2.2-litre diesel during 2026, so every 1.9 DDi is now a used purchase.· more· less
AdBlue and DPF need long runsSmall European dealer network
Buy if: You need a durable one-tonne pickup for towing and site work, cover enough distance for the particulate filter and AdBlue system to work properly, and can verify the service and campaign history.
Avoid if: Your use is short site-to-site hops with long idling periods, or you need dense dealer coverage and fast parts supply.
Maintenance costs
€850 – €1,500/year
at 15,000 km/year
Fixed costsservice, tyres, brakes€550 – €900 /yr
Risk bufferunplanned repairs€300 – €600 /yr
Price estimates are based on German asking prices. Prices and costs vary by vehicle condition and location.
Maintenance costs
Maintenance assumes 15,000 km a year. Price estimates are based on German asking prices. Prices and costs vary by vehicle condition and location.
Interrupted regeneration on short site runs loads the filter with soot and washes diesel into the engine oil · more· less
The RG D-Max cleans its exhaust with a diesel particulate filter followed by an SCR catalyst. The filter burns off accumulated soot during an active regeneration, which needs sustained load and exhaust temperature for several minutes. The duty cycle most of these trucks actually see works against that: short hops between sites, long idling for equipment or cab heating, and slow off-road running repeatedly start a cycle that never finishes. Two things follow. Soot and non-combustible ash build up until the filter restricts flow and the truck drops into reduced power. And the extra fuel injected late in the cycle to raise exhaust temperature washes past the piston rings into the sump, so the oil level rises and its lubricating quality falls. The dipstick is the giveaway: a level above the maximum mark between services, or oil that smells of diesel, means the system has been struggling. A forced regeneration or an off-vehicle filter clean at a specialist costs roughly €300 to €800. A replacement filter runs about €1,200 to €2,000 fitted. Trucks that get a weekly motorway or trunk-road run generally have no trouble at all, which is why the buyer's own use pattern matters more here than the mileage on the clock.
EGR valve and intake carbon build-up
€300 - 8002 of 10
Soot and oil vapour coat the EGR valve and intake tract, causing rough idle and lost power · more· less
Recirculated exhaust gas carries soot that combines with crankcase oil vapour into a hard, sticky deposit on the EGR valve seat and through the intake manifold. On the 1.9 this builds fastest on trucks that idle a lot or run cool, which covers site work, power take-off operation, snow clearing and short farm trips. Symptoms are a lumpy idle, hesitation off the line, higher fuel consumption and eventually an engine warning light with a logged EGR flow fault. Cleaning the valve and decoking the intake at an independent diesel specialist costs about €300 to €500. If the valve itself is seized or its actuator has failed, replacement is roughly €500 to €800. Owners who keep the truck in this kind of service usually treat a decoke as a periodic job rather than a repair, and Isuzu specialists commonly recommend doing it alongside a normal service on high-idle vehicles.
AdBlue and SCR dosing system faults
€250 - 1,2003 of 10
The RG is the first European D-Max with AdBlue, and its dosing hardware and NOx sensors are a new failure class · more· less
The previous-generation D-Max met Euro 6 in Europe with a NOx storage catalyst and no urea dosing. The RG carries a full SCR system with a 14-litre AdBlue tank mounted under the vehicle, which adds a dosing pump and injector, a heated tank and supply line, a level sender and one or more NOx sensors. Typical failures are a NOx sensor that drifts out of range, a dosing injector that crystallises because short journeys never purge the line, and a tank heater that fails and leaves the system inoperative in winter. This is not a fault you can put off: once the system logs a persistent problem the truck moves to a distance countdown and eventually will not restart. A NOx sensor is typically €250 to €500 fitted, a dosing injector or module €400 to €900, and a pump or complete tank module can reach €1,200. Isuzu has already revised the software behind the system once. UK DVSA campaign R/2024/290 of July 2024 rewrote both the engine control module and the dosing control unit on 1.9 RZ4E vehicles that could show temporary emissions irregularities under specific driving conditions. Confirm that update has been applied, and keep only high-purity AUS 32 fluid in the tank.
Clutch and dual-mass flywheel wear on manual trucks
€1,000 - 2,0004 of 10
A 360 Nm engine hauling up to 3.5 tonnes wears the clutch and flywheel faster than the odometer suggests · more· less
The 1.9 produces 360 Nm, less than the 400 Nm most rivals in this class offer, yet the four-wheel-drive versions are still rated to tow 3,500 kg braked and the 4x2 Single Cab 2,500 kg. Manual trucks worked at or near that limit, or used on site and off-road where the clutch is slipped repeatedly at low speed, wear the friction plate and load the dual-mass flywheel harder than the mileage implies. The signs are a shudder pulling away with a trailer, a high or vague biting point, and a rattle at idle that goes quiet when you press the clutch pedal, which is the flywheel springs rather than the gearbox. A clutch kit with a new dual-mass flywheel is roughly €1,000 to €2,000 fitted in Germany, most of that labour because the gearbox and, on four-wheel-drive trucks, the transfer case have to come out. This does not apply to automatic vehicles.
Rear leaf spring sag and fatigue
€400 - 9005 of 10
Constant near-payload loading flattens the rear springs and can crack a leaf at the eye bush · more· less
The RG uses a three-leaf rear pack, lighter and better riding than the older arrangement but still a working spring carrying up to about 1,100 kg of payload plus tow-ball download. Trucks that live loaded, particularly Double Cabs where the heavier cab eats into the payload margin, gradually lose ride height and spring rate. In advanced cases a leaf cracks, usually around the front eye bush or the centre bolt area. Look for an unladen truck that sits low or unevenly at the rear, for bump stops that are already touching, and for bright metal or a step at the spring eyes. A replacement pair of rear packs is roughly €400 to €900 depending on whether OEM or heavy-duty aftermarket springs are used. Many working owners fit uprated or helper springs deliberately, so a non-standard rear end is not automatically a fault, but it does tell you how the vehicle has been used.
Four-wheel-drive driveline wear and axle water ingress
€250 - 1,2006 of 10
Torn CV boots, early front wheel bearing wear, and water entering the axles through the breathers · more· less
On four-wheel-drive trucks the front constant-velocity joint boots sit in the firing line for stones, mud and pressure washers, and a torn boot lets grit and water into the joint. A clicking noise on tight low-speed turns is the classic symptom. A joint replacement is roughly €300 to €500 a side and a front wheel bearing €200 to €400 a side, and bearing noise is reported on trucks used on rough ground well before 100,000 km. Separately, the axle and transfer case breathers exit relatively low, so wading, deep standing water or a pressure-washed underside can draw water into the housings. Milky differential oil is the tell. Caught early, an oil change plus extended breather hoses costs under €250; left alone, bearing and gear damage turns it into a rebuild of €1,000 or more. Ask when the transfer case and differential oils were last changed, because these are easy items to skip on a vehicle that is only serviced to the minimum.
Chassis and underbody surface corrosion
€200 - 9007 of 10
Frame, brackets and fasteners corrode in salted regions despite the long body perforation warranty · more· less
The RG frame uses higher-tensile steel than the previous generation, and the body carries a 12-year warranty against perforation from the inside out on model year 2020 vehicles onward. Neither of those stops the exposed underside from corroding in Germany, the Netherlands, Belgium or Austria, where roads are salted through the winter. What ages first is usually not the main rails but the crossmembers, the spring hangers and shackle plates, the fuel and brake line brackets, the tow bar mounting, and the exhaust and filter fixings, plus stone-chipped areas behind the front wheels. On a truck that also spends time in mud and slurry the process is faster. Get the vehicle on a lift rather than looking from the kerb. Preventive underbody wax or cavity treatment costs about €200 to €400 and is a sensible first job on a newly bought example; localised repair, bracket replacement and treatment of an already scabby underside costs €500 to €900. Significant weakening of load-bearing structure is a periodic inspection failure in Germany, so heavy corrosion needs a proper assessment rather than a coat of paint.
Windscreen replacement and ADAS camera recalibration
€150 - 1,2008 of 10
The stereo camera behind the screen must be recalibrated after any glass replacement, or the assistance systems misbehave · more· less
Every RG carries a forward-facing stereo camera behind the windscreen that drives autonomous emergency braking, lane departure warning, lane keep assist, adaptive cruise control and traffic sign recognition. Pickups crack windscreens: site debris, gravel tracks and forestry work all take their toll. Replacing the glass on this truck means a camera-compatible screen plus a static or dynamic recalibration, which is materially more expensive than on the previous-generation D-Max. Screen and recalibration together is typically €600 to €1,200; recalibration on its own is roughly €150 to €350. The system is also widely described as intrusive even when it is working correctly, with braking and lane keep interventions that fire more readily than on most rivals, so a seller who says the alerts are just the truck being sensitive may well be right. What matters is whether there are stored camera faults and whether any replacement screen was properly recalibrated afterwards.
Variable geometry turbo actuator sticking
€600 - 1,8009 of 10
Carbon around the vane mechanism causes boost deviation faults and reduced power · more· less
The RZ4E-TC uses a variable geometry turbocharger whose vane mechanism is moved by an actuator. Soot from the EGR circuit gradually builds around the linkage, and on trucks that run cool or idle for long periods it can stick. The result is a boost pressure deviation fault, a noticeable loss of pull and, in the worst case, reduced power mode. If only the actuator has seized, a specialist can free or replace it for roughly €600 to €900. If the vanes themselves are damaged, or the turbo has lost bearing clearance, a replacement unit is more like €1,200 to €1,800 fitted. Occasional sustained load, the same driving that keeps the particulate filter clear, is what keeps the mechanism free, and it is one reason a motorway-run truck ages better than a town-bound one.
Automatic gearbox fluid overheating when towing
€250 - 2,50010 of 10
The Aisin six-speed runs hot towing near the limit, and cooked fluid shortens valve body and clutch pack life · more· less
The optional six-speed Aisin automatic is a conventional torque-converter unit and behaves well in normal use, but sustained towing near the 3,500 kg limit of the four-wheel-drive versions, particularly uphill in summer, heats the fluid. The converter lock-up clutch does not always hold under that load, and the slip that follows generates more heat again. Degraded fluid then shortens the life of the solenoids, the valve body and the clutch packs. Symptoms are delayed or harsh shifts, hunting between gears on a climb and, in bad cases, a transmission temperature warning. Trucks used regularly for towing should have the fluid changed more often than the standard schedule, roughly every 60,000 km at about €250 to €400 a time, and owners who tow at the limit often add an auxiliary cooler. If the fluid has been cooked and the valve body or converter needs attention, expect €1,500 to €2,500. Manual trucks are unaffected, and reviewers generally rate the manual as the better gearbox behind this engine.
Mechanically straightforward, but the duty cycle decides what it costs
The RZ4E-TC is a cast-iron, chain-driven, single-turbo diesel with no belt service and a design brief aimed at commercial hours, and the RG chassis and drivetrain are conventional and repairable. Almost everything on this list is driven by how the truck was used rather than by a design defect: short site runs and long idling load the particulate filter, foul the EGR circuit and stick the turbo mechanism, while towing near the limit wears clutches, flywheels, automatic gearbox fluid and rear springs. The one genuinely new area compared with the earlier D-Max is the AdBlue SCR system, which Isuzu has already revised in software. A documented truck with regular longer runs and a clean underside is a low-risk buy; an undocumented ex-site vehicle is a different proposition.
Service history
Complete Isuzu dealer or specialist records are essential. Isuzu Germany specifies service every 20,000 km or every two years for D-Max models from model year 2020, whichever comes first, and notes that severe use can require different intervals, so gaps in that record on a working truck are a warning sign.
Tires
Check tread depth, date codes and uneven wear. Confirm the load and speed rating matches the plate, because pickups are often refitted with underrated passenger tires.
Cold start
Start the engine completely cold. Listen for heavy diesel knock, turbo whine or any rattle in the first 30 seconds, and watch for smoke that does not clear.
Test drive
At least 30 minutes including a sustained motorway run. On four-wheel-drive trucks test 2H, 4H and 4L and the rear differential lock, and listen for driveline vibration under load.
Specific for this vehicle
Check the engine oil level and smell it for diesel
Oil above the maximum mark, or oil that smells of diesel, means regeneration cycles have been cut short. On a hard-worked 1.9 this is the single most important check.
Request a diagnostic read of DPF soot load and regeneration history
Ask for soot mass, ash load, distance since the last completed regeneration and the count of aborted cycles. Repeated aborted regenerations point at a short-trip life.
Check the AdBlue system for warnings and crystallisation
Look for AdBlue messages or a distance countdown in the instrument cluster, and check for white crystal deposits around the filler and the dosing injector under the vehicle.
+ 7 more checksShow less
Verify steering column campaign W9094 by VIN
It covers vehicles built between 7 September 2020 and 4 October 2022, which is most early RG production. Ask for written confirmation that it was carried out.
Inspect the rear leaf springs and unladen ride height
Check the eye bushes and the centre bolt area for cracks, and compare ride height left to right. A sagging or uneven rear end on an empty truck means fatigued springs.
Inspect the ladder frame, crossmembers and fasteners on a lift
The 12-year perforation warranty covers body panels from the inside out. It does not stop surface corrosion on the frame, spring hangers, line brackets and suspension fixings in salted regions.
Test the assistance systems and check the windscreen
Confirm there are no camera or radar fault messages, and establish whether the screen has been replaced. A screen fitted without recalibration causes false emergency braking and lane keep interventions.
Check clutch bite and listen for flywheel rattle (manual only)
Judder pulling away and a rattle at idle that goes quiet when the clutch pedal is pressed both point at a worn dual-mass flywheel, which is common on trucks used for heavy towing.
Check differential and transfer case oil and breather routing
Milky oil means water has entered through the breathers during wading or washing. Ask when the transfer case and differential oils were last changed.
Look for signs of heavy commercial use
Check the load bed, tow ball wear, bolt holes from a tipper body or crane, and any power take-off equipment. Long idling periods accelerate EGR and particulate filter fouling.
Recalls and Technical Service Bulletins
Rear outboard seatbelt pre-tensioner wiring connector may not be fully locked in position (Isuzu campaign W9086, vehicles built September 2020 to January 2021, UK DVSA campaign launched 26 March 2021)Verify completed
Incorrect tightening torque on the lower steering column universal joint bolt, which can cause loss of steering (Isuzu campaign W9094, vehicles built 7 September 2020 to 4 October 2022; UK DVSA R/2023/075 of 24 March 2023 and German KBA action of 21 April 2023 covering 1,333 vehicles, 939 of them in Germany)Critical - verify completed
Engine control module and AdBlue dosing control unit software update for temporary emissions irregularities under specific driving conditions on 1.9 RZ4E vehicles (UK DVSA R/2024/290 of 24 July 2024)Verify completed
The steering column campaign W9094 is the one to clear first, because its build window from 7 September 2020 to 4 October 2022 covers most early RG production and the failure mode is loss of steering. The German action alone covered 1,333 vehicles, 939 of them registered in Germany. The 2024 software campaign is recorded with the UK DVSA, so on a continental vehicle ask Isuzu directly with the VIN whether the same engine control and dosing control unit update applies to that chassis number. Isuzu's European dealer network is small, so confirm your nearest dealer can pull the full campaign history before you commit. Contact Isuzu with the VIN to verify all recalls have been completed.
Warranty Status
Germany and Austria factory warranty (5 years / 100,000 km)Usually ended on the kilometre limit first
UK factory warranty (5 years / 125,000 miles)Running out through 2026 on 2021 registrations, sooner if the mileage cap is reached
Body perforation warranty (12 years, model year 2020 onward)Still active on every RG D-Max
Mobility guarantee, Germany and Austria (3 years)Expired on 2020 to 2022 vehicles, ending during 2026 on 2023 registrations
Isuzu's terms are set by the national importer rather than by a single European policy, so check which market the vehicle was first sold in. Isuzu Sales Deutschland states 5 years or 100,000 km from first registration, whichever comes first, for model year 2017 onward, plus a 12-year warranty against body perforation from the inside out for model year 2020 onward and a 3-year mobility guarantee with Europ Assistance for vehicles registered in Germany or Austria. Isuzu UK states 5 years or 125,000 miles. On a working truck the distance cap matters far more than the years: at 30,000 km a year the German warranty is used up in well under four years, so most examples on the used market are already outside it on mileage even when the calendar term looks intact.
Sources: Research draws on model-specific owner forums and owner communities, recall information from official authorities, German automotive press, and multiple workshop cost references cross-checked against each other.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.
