When the power goes out, the difference between a basic generator and a capable inverter model quickly becomes clear. Keeping essential appliances running, from fridges and lights to sensitive electronics, requires reliable power output, quieter operation and enough capacity to handle higher-demand devices.
The Gentrax GTX6600 Inverter Generator is designed for those who need more power without stepping up to a bulky open-frame unit. With a 6.6kW maximum output, it is built for demanding applications including caravanning, worksites and home backup. This review explores its power capabilities, features, portability and overall value to determine whether it is the right choice for those needing serious portable power.
The short version
Best for: Caravanners and off-grid campers running fridges, air conditioning and multiple devices at once, tradies on remote sites, and homeowners who want a genuine standby option through storm season.
Standout features: Clean inverter power with a 1.0 power factor, wireless key fob start, a proper economy mode for quiet running, an Australian 30A industrial socket, and a digital display that reads out volts, amps and running hours.
Keep in mind: It ships with no oil in it, it is petrol only, and at roughly 89 kilograms it is a two-person lift into a ute tray.
The Numbers That Matter
| Type | Petrol inverter generator, air-cooled four-stroke OHV single cylinder |
| Maximum output | 6.6 kW |
| Rated (continuous) output | 6.0 kW |
| AC output | 240V, 50Hz, power factor 1.0 |
| DC and USB output | 12V / 5.0A and 5V / 3.1A USB |
| Engine | 389cc, 88 x 64 mm bore and stroke |
| Fuel and tank | Unleaded petrol, 18.5 litre tank |
| Runtime | About 4 hours 30 minutes at full 100% load |
| Starting | Electric start plus wireless remote key fob |
| Outlets | Australian 30A industrial socket, 15A AC receptacle, USB, 12V DC |
| Oil | SAE 10W30, 1.1 litre capacity (not supplied) |
| Spark plug | F6RTC, 0.6 to 0.7 mm gap |
| Weight | Around 89 kg |
| Dimensions (L x W x H) | 750 x 537 x 630 mm |
What the GTX6600 Actually Is
Strip away the marketing, and the Gentrax GTX6600 is a petrol-driven inverter generator built around a 389cc air-cooled four-stroke engine. The word that earns its keep here is inverter. Rather than spinning an alternator at a fixed speed and hoping the waveform stays clean, an inverter generator produces raw AC, converts it to DC, then rebuilds it electronically into smooth, stable 240-volt power. In practical terms, that means it is safe for the sensitive electronics a conventional generator can quietly cook: laptops, phones, modern TVs, medical devices, and battery chargers. If you have ever hesitated before plugging a good laptop into a job site generator, this is the format that fixes that worry.
Gentrax positions the GTX6600 at the powerful end of the portable market, and the headline figure is a 6.6 kilowatt maximum output with 6.0 kilowatts available continuously. That is enough to run a caravan air conditioner, a fridge, lighting, and a few devices at the same time, or to keep the important circuits of a house ticking over during a blackout.
Here’s what one of our customers said:
“I bought the equivalent model back in 2018 and it’s still going strong. Starts first time every time. We use it to power a donut machine on a food van, it runs for 8 hours straight and has never skipped a beat! The only thing that has tried is the wheel lock. I’d happily buy another.”
Power and Performance
It punches above the average camp generator. Plenty of portable inverters top out around 2 to 3 kilowatts, which is fine for charging and small appliances, but runs out of headroom the moment you ask for air conditioning or power tools. The GTX6600’s 6.0 kilowatt continuous rating gives you genuine room to move. In real-world terms, you can run a rooftop air conditioner and a fridge and still have capacity spare for a kettle or a power tool, which is the sort of combined draw that stalls smaller units.
The power quality is the quiet win. A power factor of 1.0 tells you the rated kilowatts translate almost directly into usable power, with very little lost to reactive load. Combined with the inverter’s clean waveform, that makes the GTX6600 as comfortable running a laptop as it is running a drop saw. For anyone powering a mix of resistive gear like heaters and kettles alongside electronics, that consistency is worth more than a slightly higher peak figure on a cheaper machine.
The one honest caveat is surge behaviour. Devices with a big starting current, such as a compressor or a submersible pump, will briefly draw far more than their running wattage. Gentrax is upfront that you must switch the economy mode off before starting gear like this, so the engine is already at full revs and ready to deliver the surge. Get that sequence right, and it copes well. Forget it, and you will trip the overload protection until you reset it.
Runtime and Fuel Economy
The GTX6600 carries an 18.5-litre petrol tank, which is generous for a portable, and Gentrax rates it for about four and a half hours of continuous running at a full 100 per cent load. That is the worst-case figure. Very few users sit at full load for hours on end, and this is where the economy mode earns its place.
Economy mode is more than a marketing switch. Flick it on, and an economy control unit matches engine speed to the actual connected load rather than holding full revs regardless. Ask for less power, and the engine backs off, which means less fuel burned and noticeably less noise. Across a typical camp day, where you are running a fridge and a few devices most of the time and only spiking when the air conditioner or kettle kicks in, that adaptive behaviour stretches a single tank a long way beyond the rated full load figure. It is the difference between refuelling mid-afternoon and refuelling once a day.
Starting It: Electric and Remote
There is no wrestling with a pull cord here, and this is one of the GTX6600’s genuinely lovely touches. It offers push-button electric start from the panel, and a wireless remote key fob that starts and stops the engine from a distance. Picture standing on your back veranda during a blackout and bringing the generator to life from inside the dry, or firing it up from your camp chair without leaving the fire. Two presses of the fob and a ten-second wait if it needs a second go, and you are running.
A small but important discipline. Because the remote receiver stays awake listening for the fob, Gentrax recommends returning the engine switch to STOP when the machine is packed away; otherwise it slowly drains the 12-volt battery. The company also advises charging that battery at least every two months. None of this is unusual for a remote start generator, but it is the sort of habit worth building early so you are never caught with a flat battery and no start.
Noise and the Economy Mode
Inverter generators are known for being quieter than traditional open-frame models, and the GTX6600’s Economy Mode helps improve both noise levels and fuel efficiency during lighter loads. By automatically adjusting engine speed based on power demand, the generator can reduce unnecessary engine output when full capacity is not required.
The Gentrax GTX6600 operates at 62 dB at 7 metres, making it a quieter option for a generator of its size. While a 6.6kW generator will naturally produce more sound when running at higher loads, its inverter technology and enclosed design help maintain more comfortable noise levels for applications such as camping, caravanning, and backup power.
Here’s what one of our customers said:
“Works well, starts super easy every time. I just bought a second one!! :)”
Outputs: What You Can Actually Plug In
This is an area where the GTX6600 shows it is built for serious, mixed use rather than just topping up a phone.
- Australian 30A industrial socket. The standout inclusion. This is the high-current three-pin outlet that caravans and larger setups use, so you can run a van or a serious appliance directly rather than daisy-chaining adaptors.
- 15A AC receptacle. For heavier-duty household and trade gear that a standard 10-amp point cannot legally supply.
- USB output. A 5-volt, 3.1-amp USB port for charging phones and tablets straight off the generator, no adaptor needed.
- 12V DC receptacle. A 12-volt, 5-amp DC output, handy for charging a separate 12-volt battery, with a dedicated DC circuit protector watching over it.
Each AC outlet is individually protected, so an overload on one circuit does not necessarily take everything down with it.
Build Quality and Moving 89 Kilos
It is solid, and it is heavy. There is no getting around it: at roughly 89 kilograms, this is a substantial machine. Gentrax has sensibly fitted it with wheels and a carrying handle, and there is a brake lever to stop it rolling away once you have positioned it, which is a thoughtful detail on sloping ground. On flat ground, one person can wheel it around comfortably. Lifting it into a ute tray or up a set of steps, though, is firmly a two-person job. If your use case involves a lot of lifting rather than rolling, factor that in.
The layout is sensible. Fuel gauge on top, a clearly laid out control panel, and access panels for the air filter, spark plug, and oil that make routine servicing straightforward rather than a knuckle-skinning ordeal. This is a machine designed to be maintained by its owner, not just its dealer, which bodes well for long-term ownership.
The Digital Brain: Display and Safety Systems
One of the features that separates the GTX6600 from cheaper units is its data display instrument. Rather than leaving you guessing, it cycles through output voltage, current, power in volt-amps, and both total and current running hours. That running hour counter alone is worth having, because it lets you service the machine on schedule instead of by rough memory.
Just as usefully, the display doubles as a diagnostic panel. A green OUTPUT light confirms healthy running, a red FAULT light warns of an overload or defect, and a yellow light flags low oil. When something is wrong, it shows a specific code, from high or low AC voltage through to controller or IGBT over-temperature, so a fault becomes a readable message rather than a mystery. Layered underneath that are the protections you want and hope never to need:
- Oil warning system. If the oil drops below a safe level, the engine shuts down automatically and will not restart until you top it up, which quietly protects the engine from the single most common cause of premature death.
- Overload protection with output reset. Draw too much, and the electronic breaker cuts AC output to protect the generator and whatever is plugged into it. Shed the excess load, hold the reset button for two seconds, and power returns.
- DC circuit protector. A separate guard for the 12-volt charging circuit that trips if that side is overloaded.
Real-World Use Cases
Caravan and off-grid camping. This is the GTX6600’s natural home. The 30-amp industrial socket, the air conditioner-friendly output, and the quiet economy mode make it a strong match for extended free camping, where you need real power without annoying every van around you.
Tradies and remote sites. Six kilowatts of clean, continuous power runs most site tools, and the inverter waveform means you can charge expensive battery platforms and run a laptop without worry. The remote start is a genuine convenience at the start of a cold morning.
Home backup. For anyone in a storm-prone or bushfire-affected area, the GTX6600 makes a credible standby unit for keeping a fridge, freezer, lighting, and communications alive during an extended outage. The remote start lets you bring it up from shelter, and the runtime is enough to bridge most grid interruptions with a spare jerry can on hand.
Events and markets. Stallholders and event organisers get clean, quiet power with enough headroom for lighting, refrigeration, and point of sale gear in one machine.
Living with It: Maintenance and Upkeep
A generator is a long-term relationship, so upkeep matters. The good news is the GTX6600 is refreshingly conventional to look after.
- First, and do not skip this: the GTX6600 ships with no engine oil in it. You must add oil before the very first start, or you will not get it running, and you risk damage if you force it. It takes 1.1 litres of SAE 10W30.
- Oil changes. Check the level before every use, change the oil after the first month or 20 hours, then every 100 hours or six months thereafter.
- Air filter. A washable foam element you clean in solvent, re-oil lightly and refit, roughly every 50 hours. Never run the engine without it fitted, as unfiltered grit wears an engine out fast.
- Spark plug. A standard F6RTC plug set to a 0.6 to 0.7 mm gap, checked every 100 hours.
- Long-term storage. Drain the fuel from the tank and carburettor, put a little oil into the cylinder through the plug hole, and store it upright somewhere dry and well-ventilated. Petrol left to go stale in a carburettor is the number one reason generators refuse to start after a season in the shed.
Handled with that basic discipline, there is no reason a machine of this build should not give many years of service. As always, the caveat is that no manufacturer can protect a generator from neglect, and stale fuel and skipped oil changes will kill any engine regardless of badge.
Where the GTX6600 Falls Short
No honest review is a list of virtues, so here is the balancing side of the ledger.
- It is heavy. At around 89 kilograms, it is not a machine you casually pick up. The wheels help, but any lifting is a two-person job.
- Petrol only. There is no dual fuel or LPG option here, so you are tied to keeping fresh unleaded on hand and managing stale fuel over long idle periods.
- No published noise rating. Gentrax leans on the quiet inverter story but does not give a decibel figure for this model, so you are taking that claim partly on trust rather than a spec.
- Battery housekeeping. The remote start convenience comes with the responsibility of keeping the battery charged and switching the engine fully off in storage, or you will find it flat when you need it.
- No oil in the box. A minor gripe, but worth repeating because it catches people out: you cannot run it straight out of the carton without buying oil first.
The Verdict
The Gentrax GTX6600 Inverter Generator is a genuinely capable machine that backs up its badge. It pairs a strong 6.0-kilowatt continuous output with the clean, electronics-safe power an inverter design is prized for, then wraps it in the conveniences that actually change how you live with a generator: push-button and remote start, a real economy mode, an Australian 30A socket, and a display that tells you what is going on. For caravanners, off-grid campers, tradies, and anyone building a serious home backup plan, it sits in a sweet spot of power, refinement and usability.
It is not flawless. The weight demands respect, and it is petrol-only, but neither is a dealbreaker for the buyer this machine is built for. If you need real, clean, quiet power and you are willing to give it the basic care any four-stroke engine deserves, the GTX6600 is very easy to recommend.
