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WEN GN400i Review – Best 4000 Watt Open Frame Generator?

Let’s say it upfront – WEN generators are among our favorites.

That’s because they are solid, reliable and finally – very affordable.

In terms of quality, they can compete with Champion, Westinghouse or even Honda while costing only a fraction of the price.

WEN GN400i is a very inexpensive 4000-watt open frame inverter generator suitable for those users who need a bit more power than the 2000 and 3000-watt inverters can offer.

But is it that good? Can you trust a generator that cheap to deliver its job?

We’re going to reveal the answer now in the following WEN GN400i review.

WEN GN400i – first impressions

Typical small inverter generators are a great choice if you need a quiet and lightweight generator to run sensitive electronics. The problem with most of them is that unless you run them in parallel, they’re usually too small to power anything bigger like a 15,000 BTU RV air conditioner.

They’re also significantly more expensive than the ordinary open frame generators.

That’s when the generators like WEN GN400i come into play.

This generator combines the best of both worlds.

It offers the clean electricity of an inverter generator with the low price tag and power of a 4000-watt generator.

That makes it an excellent choice for a variety of applications.

The generator’s control panel features 2 x 120V NEMA 5-20R receptacles, 1 x 120V transfer-switch-ready NEMA L5-30R twist lock receptacle and 2 x 5V USB ports.

WEN GN400i – Technical Specifications

  • Wattage: 4000 Starting / 3500 Running Watts
  • Fuel Type: Gasoline
  • Fuel Tank Capacity: 1.85 gal
  • Run Time: 7h @ 50% load
  • Outlets: 2 x 120V AC , 1 x 30 amp RV outlet, 1 x 12V DC, 2 x USB ports
  • Weight: 70.5 lbs
  • Dimensions: 19.8 x 13.8 x 18.9
  • Engine: 212cc 4-stroke OHV
  • Starting Method: Manual Recoil / Electric

 WEN GN400i control panel

Advantages of WEN GN400i


Compared to the conventional open frame gensets, WEN GN400i weighs significantly less and is easier to transport.

Depending on which specific generator you compare it to, we’re talking about 30% difference in weight in favor or WEN GN400i.

The unit weighs 70.5 pounds which is also less than some less powerful inverter generators weigh.

That’s clearly a big selling point of this generator.

Quiet Operation

One massive issue with most portable generators of this size is how loud they are.

That makes them annoying to use when you need a quiet generator for camping or RV.

Plenty of RV parks do not even allow the generators making more than 65 decibels of noise at their premises.

Fortunately, thanks to its inverter technology WEN GN400i is much quieter than most 4000-watt generators.

Even at the higher loads, its engine noise stays at the lower side.

Inverter Technology

Inverter generators are a much better modern alternative to conventional generators.

They are not only quieter and lighter but also produce cleaner electricity.

You can use them to charge your portable electronics including laptops, tablets or cameras without any problems.

Another great thing about the inverters like WEN GN400i is that you can run it in parallel with another same unit to double your total power output.

This solution would give you in total of up to 8000 starting watts at your disposal. That’s already enough to provide power for most of your critical household devices in the event of a power outage.


WEN is known for making good generators which also sell for cheap.

WEN GN400i is nearly half as cheap as some of its competitors.

By purchasing this generator instead of let’s say a Yamaha, you can save yourself a good couple of hundred bucks.

It does not mean that WEN is inferior in quality though.

Numerous reports online confirm that most of the users are very satisfied with this unit and have never encountered any serious problems associated with it.

All in all, the most important part of the generator is its engine.

WEN does not skimp on quality of their generator engines and this one is no exception.

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WEN GN400i

Any Cons?

To be honest there is nothing to seriously complain about this generator.

You would be hard-pressed to find another 4000-watt inverter generator that can compete with WEN GN400i in terms of its price to quality ratio.

Some users have reported minor gas leakage problems.

However, these seem to be very rare individual occurrences.

In case anything like this happens to you, you are fully covered by a 2-year warranty which should help you fix your trouble in no time.

Conclusion – should you buy WEN GN400i?

If you need a good and cheap 4000-watt portable generator I would heavily recommend you to have a closer look at this one.

This is also one of the only few inverter generators in this wattage range usually selling for much less than $1000.

This generator combines the best of both worlds – large power and the lower price tag of an open frame generator with all the benefits of an inverter.

To sum up – I think it’s worth purchasing.

9 Total Score
Good and Cheap RV generator

Noise Level
Ease of Use
  • Inverter Technology
  • High Wattage
  • Very Quiet
  • Cheap
  • Nothing to really complain about!

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