Predator 4375 Spec Review

The Predator 4375 (63960) is a compact open frame generator with a rated wattage of 3500 W and a starting wattage of 4375 W.

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Predator 4375Predator 4375Predator 4375Predator 4375
Note: Predator Generators purchased at Harbor Freight do not include the wheel kit, which is a separate purchase. Other sellers may include it.
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Our new Predator® line has been updated with your convenience and safety in mind. Powered by a reliable Predator® gas engine, this generator is ideal for emergencies, job-sites, food trucks, and outdoor recreation. GFCI outlets, larger fuel tank, longer run time make this generator an unbeatable value. 4375 starting watts and 3500 running watts make this unit capable of powering several home essentials during an outage or providing power on the go. Our new, larger gas tank means you can enjoy run times up to 16 hours @ 50% load.

Zoom on the Predator 4375

In summary, the Predator 4375 is a compact portable generator especially useful for:

  • RV travellers who wish to upgrade their experience to another level
  • Occasional participants of outdoor events, competitions, concerts and festivals
  • DIYers who wish to improve their efficiency with tools
  • Homeowners who want to be sure of their ability to power their fridges, cooking tools, heating and lighting equipment during power failures
  • Professionals who want to be able to deliver results, even during a power failure

The following sections will present you in detail its power characteristics, the different outlets it offers, its overall portability, the extra features it benefits from, and any relevant emission compliance details.

Power & Run Time

The Predator 4375's design includes a gasoline-fueled 212 cc (6.5 hp) OHV 4-stroke engine. With a 120/240V output, it gives a running wattage of 3500W and also a peak wattage of 4375W.

At a noise rating of 72 dBA (just slightly more noisy than a dishwasher), the generator is started via a conventional pull-start mechanism.

Thanks to a fuel capacity of 4 gallons, the 4375 can operate for around 16 hours at 50% load with a full tank (fuel consumption around 0.25 GPH).


The control panel features the upcoming 5 AC outlets:

Two Duplexes 120V 20A (5-20R) GFCI
120/240V 30A (L14-30R) receptacle

Furthermore, it has 1 DC outlet: there's a 12V 8A (cigarette lighter style) receptacle allowing you to easily charge your batteries.

As it features a twist-lock L14-30R receptacle, the 4375 is transfer switch ready: in case of a power outage, you will be easily able to connect it to a breaker box and power your household.


The Predator 4375 has a conventional, open frame design, of the following dimensions: L23.3 x W18.7 x H19.3 in, which offers support and allows it to be raised above ground level. This type of design is ideal for tough environments and heavy outdoor use.

Since the generator weighs 103.5 lbs, it will be incredibly difficult to manually lift it and transport it, even though it is technically considered to 'be portable' (in the sense that it is movable). However, its challenging mobility is solved by a wheel kit (separate purchase), which will ease its displacement, once it is on the floor.


Panel of the Predator 4375

The 4375's control panel

When its oil levels are insufficient, you will be informed by the featured light indicator.

Thanks to a built-in fuel gauge, the generator allows you to quickly, conveniently and easily check the gas level at a glance.

From a security standpoint, the product offers an automatic low oil shut-off and an overload protection (circuit breaker), allowing you to use it with a peace of mind.

Besides the features previously mentioned, accessory-wise, the Predator 4375 comes with the usual documentation and owner's manual (opens in a new tab) needed to get you promptly started.


The Predator 4375 is EPA-approved and CARB-compliant. Thus, selling and purchasing this generator is allowed in each of the 50 states, including California.

Moreover, it features a spark arrestor, so it is adequate for use in forested areas.

Product Videos

The Predator 4375 versus other generators

The following charts are provided to give you an idea of how some of the key specs of the Predator 4375 compare to generators of similar power (between 3000 and 4000 W).

  • At a weight of 103.5 pounds, the Predator 4375 places in the expected weight range of the generators in the 3000-4000 rated wattage range. If weight is your top priority, one of the champions in this power category is the WEN GN400i, weighing just 66.1 pounds.
  • When compared to devices able to produce a similar running wattage, this generator and its lowest emitted noise of 72 dBA is on the noisier side. If you’d prefer a less noisy device, one of the most quiet devices, which share the same power range with this one, is the Cat INV4000E, whose lowest noise levels reach just 51 dBA.
  • With a run time of around 16 hours at 50% load, the 4375 has one of the highest run times, compared to its similarly powerful peers.
  • Even though run times are undoubtedly important, they are dependent on the fuel capacity to a large extent. For a more wholesome picture, we must take into consideration the fuel consumption of the generator. This generator, with an estimated fuel consumption of just 0.25 GPH (gallon per hour) at 50% load, is one of the more fuel efficient generators, for the previously mentioned wattage range. If you are concerned with gasoline efficiency, having a fuel consumption of just 0.17 GPH, the Westinghouse iGen4200 is a device you should look out for.

Here's a list of the most popular specific comparisons:

Price comparison

As you can see from this interactive chart, when compared to other 3000-4000W generators, the Predator 4375 is on the cheap side of the price range.

It can therefore be a really good buy if you're looking to acquire a budget generator.

The bottom line

  • Inexpensive
  • GFCI Outlets
  • High run time
  • Fuel efficient
  • Decent weight (103.5 lbs)
  • No data center
  • No electric start
  • Wheel kit not included
  • Weak warranty
  • On the noisy side (72 dBA)

Do you own the Predator 4375 and agree (or disagree) with these strengths and weaknesses?

Let us know and write your own review.

Features and Specifications

Parallel capableNo
RV readyNo
Engine212 cc OHV 4-stroke
Starting systemRecoil
VoltageAC: 120/240V 60 Hz, DC: 12V
Running watts3500 W
Starting watts4375 W
Running amps (@120/240V)29.2/14.6 amps
Peak amps (@120/240V)36.5/18.2 amps
Run time @50% load16 h
Run time @25% loadUnknown
GFCI outletsYes
Covered outletsNo
Automatic Voltage RegulationYes
AC outlets
  • 2x Duplex 120V 20A (5-20R) GFCI
  • 1x 120/240V 30A (L14-30R)
DC outlets1x 12V 8A (cigarette lighter style)
Data centerNo
IndicatorsLow oil
Fuel tank4 gal
Fuel gaugeYes
Weight103.5 lbs
Approx. dimensions (L x W x H)23.3 x 18.7 x 19.3 in
Noise (lower limit)72 dBA
EmissionsCARB, EPA
SecurityLow oil and overload protection
Spark arrestorYes
NeutralBonded to frame
Accessories includedNo
Warranty90 days

Unlike many websites, we did our best to research each of the specs above. That being said, we are not immune to making the occasional mistake or omission. Should you notice any missing or incorrect values, don't hesitate to suggest improvements so we can address the issue.


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About Predator

Predator portable generators are solely distributed by the Harbor Freight Corporation, which has an impressive list of over 200 trademarked products. The Predator brand is one of their newer lines of outdoor power products. As with many other makes and models of power equipment sold by Harbor Freight, Predator generators are manufactured in China.

Warranty Information

The Predator 4375 is covered under a warranty for up to 90 days. This warranty may be limited and may not cover all parts of the generator.
For more information about the warranty of Predator generators, please consult Predator's warranty policies stated in the user manual (opens in a new tab). Alternatively, you can also contact their Customer Support : 1-800-444-3353.

Questions & Answers

What can it power?
Examples of items that can be simultaneously powered.
The examples below are based on a maximum load of 80% and estimated wattages. For a more accurate estimation, use our generator size calculator.
ItemRunning WattsStarting Watts
At homeSump pump (1/2 hp)10502150
Furnace fan (1/2 hp)8752350
Refrigerator (energy star)1921192
Rice cooker650650
Total2767 W4242 W
For campingRadiant heater13001300
RV refrigerator180600
RV AC (11,000 BTU)10101600
Slow cooker270270
Total2760 W3350 W
For workGrinder14002500
Demolition hammer12601260
Bug zapper8080
Total2740 W3840 W
Is there a drain plug for gas on the generator for long term storage? (Asked April 29, 2020)

It doesn't seem that there are any. I'd suggest to contact Harbor Freight to make sure.

Does this generator have an inverter? (Asked June 10, 2020)

This unit is not an inverter generator.

how do i change the oil (Asked August 21, 2020)

Oil change procedure is detailed page 17 of the owner's manual (opens in a new tab).

What spark should I use and what is the gap setting (Asked August 23, 2020)

Spark plug type is NHSP/Torch F6TC. Gap setting is 0.027" – 0.031".

What kind of oil (Asked August 28, 2020)

Recommended engine oil is SAE 10W – 30 above 32° F, and SAE 5W – 30 at 32° F or below

What grade of gas? (Asked September 08, 2020)

Recommended gas is 87 octane or higher unleaded gasoline that has been treated with a fuel stabilizer additive.

Do you have to ground this generator predator 4375 (Asked September 08, 2020)

It is always safer to ground your generator.

Can I connect my RV 30 amp cord into the 120/240V 30A (L14-30R) receptacle? The panel says 15A max??? (Asked October 10, 2020)

You absolutely can. You just won't pull more than 15A amps out of it.

Can the 4375 be connected directly to the my homes' main panel box? (Asked October 17, 2020)

It can be connected to a transfer switch. Note that this connection should be made by a licensed electrician.

How much oil does the Predator 4375 hold? I cannot find that info anywhere. (Asked November 01, 2020)

Engine oil capacity is 0.6 quarts.

Does this model have carbon monoxide that automatically shuts off if level gets too high? If machine is placed 30ft from home with "exhaust" pointed away from home safe enough?can strong wind blow CO back to home at a dangerous level? As home health nurse,I had 2 patients,separate cases I had send to morgue,so I know danger! (Asked December 27, 2020)

This unit does not have a CO monitoring feature. You may check this list of generators, which have a similar wattage output and benefit from a CO sensor. We recommend also reading our safety guide.

Can the generator be ran in snowy conditions (Asked February 15, 2021)

Please refer to our article on operating a generator in bad weather.

My question concerns the 240 volt outlet total amperage output. It lists here at (1x 120/240V 30A (L14-30R). So I take this to mean 30 amps even though the label painted on the side says 15 amps maximum. 30 amps would make sense as its combining both of the 15 amp 120 volt circuits. The 4375, the 6500, and the Predator 9000 all list identical outputs in the descriptions but on the unit they differ. So just trying to confirm total amp output as I plan on hooking up to the house panel. (Asked February 17, 2021)

It means that the outlet is 30 amps, as per its NEMA nomenclature (L14-30R). For the Predator 4375, this outlet won't output more than 15 amp. 15A x 240V = 3600W.

What are the valve gaps set at (Asked March 09, 2021)

Intake 0.004" – 0.006", Exhaust 0.006" – 0.008"

What’s the wiring look like mine came undone need to wire the start Hutton back up (Asked August 19, 2021)

The wiring diagram can be obtained through Harbor Freight's Customer Service: 1-800-444-3353.

Is the 240 outlet GFI protected (Asked September 06, 2021)

Only the two 5-20R duplexes are GFCI protected.

Does this unit require a battery? (Asked October 01, 2021)

The unit does not require a battery.

Couldn't find the right answer for you? Ask your own question.

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Predator 4375
7.5 Total Score
6 reviews
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6 Reviews
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  1. 3.15

    Love this product, always wanted to own. Generator and this one was perfect for the price and accessibility.

    + PROS:
    • compact, with wheel cart easily movable, price was good.
    - CONS:
    • loud (being a generator and all), have to buy the other accessories including a grounding wire.
    Helpful(7) Unhelpful(3)You have already voted this
  2. 4.5

    I bought the generator wheel kit. I watched a video about the generator. In the video, the man said he’d originally put the wheel mounts on backwards. I looked at the instructions. I tried to determine how to attach the wheel mounts. The kit didn’t come with the correct washers. I couldn’t attach the mounts with the provided washers. I wanted to put washers on both sides of the wheels. That’s what the directions show. I have lots of spare nuts, washers, etc. Unfortunately, didn’t have what was necessary. I had to make a run to the hardware store.
    I agree that the oil fill is in a poor location. The generator seems well built. Hopefully, I’ll get many years of use out of it.

    + PROS:
    • Will power a reasonable load.
    - CONS:
    • Doesn't come with a wheel package included. Oil fill is rather inconvenient. Could be a little quieter.
    Helpful(9) Unhelpful(1)You have already voted this
  3. 4.15

    Bought the generator as a backup power source for our home. Had to buy a wheel kit, but it was easy to install. Wished it had a data center, but I bought one via AMAZON. Hooked the generator to the house panel after having the panel fitted for it. The generator works perfectly in powering everything except the central air, it would power the central heat though. Overall…very happy with the purchase!

    + PROS:
    • Powers tho home via electrical panel
    • Value
    • Easy setup
    • Easy start
    • Portability
    - CONS:
    • Loud, even for a generator
    • No data center
    • No outlet covers
    • No wheel kit
    Helpful(2) Unhelpful(0)You have already voted this
  4. 2.9

    Gfi outlets trip continuously while running only 7 amps!! Cannot replace existing 110 ac gfi outlets on the control panel. I have an 1800 Ironton generator that will run the same 7 amp equipment all day long!! I would not recommend purchasing a predator 4375 Generator!!

    + PROS:
    • Starts easily, quite,runs great
    - CONS:
    • Gfi trips
    Helpful(2) Unhelpful(0)You have already voted this
  5. 5

    Ran our home during a 4~ day outage. Used the HF 50’ generator cable with it. Ran our fridge, all lights, 10k BTU AC, multiple fans and more with ease. Very good on gas. Noise isn’t bad at all. Sounds like every other generator I’ve ever heard.

    I live in a neighborhood, if my neighbors are bothered by the noise, they can chip in. Can’t even hear this generator on my back deck while inside with the doors shut.

    Really should come with the wheel kit as the photos advertise it with it.

    + PROS:
    • Great value.
    • Long runtime.
    • Easy to start.
    • Not louder than any other generator I’ve ever heard.
    - CONS:
    • Really needs wheel kit. Oil fill in poor location.
    Helpful(0) Unhelpful(0)You have already voted this
  6. 2.75

    Mine only lasted me one year and 2 weeks then engine locked up

    + PROS:
    • Loved it , bought it August 28 of 2020
    - CONS:
    • Engine locked up on September 22 of 2021, need to get it replaced how can I do this still looks brand new
    Helpful(0) Unhelpful(0)You have already voted this

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