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KOHLER K-3979-96 Highline Review

The K-3979-96 is one of the KOHLER toilet models that comes equipped with an elongated bowl with a more comfortable height. Couple this with its great bulk waste flushing performance, which according to the manufacturer is labelled as class five, and you have two of, what we see to be, the most important specifications covered.

But what can be said about its other functions and capabilities? We have written up the facts below, which are designed to aid you in deciding whether or not this is a suitable match for you.

Spec overview

Image Product Flush GPF Bowl Rating?
Gravity 1.6 Elongated 87%


To help you find the top flush toilet for your home we have spent many hours researching and pulling together all the pieces of information we can find about individual products so that you have an online resource to make comparisons and come to your own conclusions. Listed below, readers will find out more about what to expect from this particular model, and what to watch out for whilst shopping.

Rough in - The distance between the wall and waste outlets hold down bolts will let you know your own rough in size. This one is 12" which is quite a common measurement for the residential sector. In fact, you will see that the majority of products online are built for that particular size. It's more than likely your own washroom will be suitable for it, however, a little bit of research and measurements should also be done yourself. Learn how to do that here.

Flushing mechanism - In terms of flush performance, this is a model that is up there with the best, offering class 5, 1000 MaP rating. Which is pretty much as good as you're going to find for this price range. The mechanism it operates on is a 1.6 gallon, single, gravity fed flush.

Water usage - So, with such positive things being said about its flush, what about its overall efficiency? Well sadly, this isn't a unit that'll make you huge savings on water. This will send 1.6 gallons through the bowl, which is inline with what's seen as standard these days, but more efficient than the really old styles that consume above three gallons.

Design - A feww things you should be aware of about the design. Right off the bat, the bowl is slightly taller than your standard styles, offering similarities to a chairs height. These are designed to be more accessible for adults and easier on the joints and muscles of the body. Without the seat, the measurement from the base to the top of the rim is sizteen and a half inches, which goes above seventeen inches when you factor in the seat being attached. Making it ADA compliant.

How does it compare to other toilets?

Save yourself the time of reading through a variety of different claims and opinions online by making your own comparisons using the table below.

K-3979-96 Highline K-3810-0 Santa Rosa K-4007-0 San Souci
Flush Gravity HET HET
GPF 1.6 1.28 1.28
Bowl Elongated Elongated Round front
Comfort height
Color Biscuit White White
Dimensions 31.2 x 29.8 x 18" 31 x 20.8 x 29" 25.6 x 16.8 x 24.2"
Weight 93 lbs 102 lbs 92 lbs
Rating 87% 86% 87%

Considerations before you buy

How big is your bathroom? - The amount of space afforded to you, and how big the toilet is should play a massive role in what model you end up choosing. This isn't going to be the smallest of options available simply because it's elongated and measures 31.2 by 29.8 by 18 inches. However, if you're not too concerned with size or efficiency, this could be a suitable choice.

Mount - This is a floor mounted product. However, if that isn't to your personal taste, there is alternative ways to present the hardware in your bathroom. One such example is a hanging toilet which usually has a hidden tank and carrier system built behind the wall, minimizing the overall footprint, and improving the aesthetics.

Consumer reports - When shopping around, you should keep your eyes open looking for an insight through the buyers point of view. The smart and sensible way to do that is by reading as many comments and reviews left online. Some will not necessarily provide anything useful to you, but there will be times where you get an important piece of information about a products flaws and whether or not it's worth buying. However, be wary that not all feedback will be genuine, some have been known to be fake in self promotion.

Budget - A good budget range to stick within is anywhere between 300 through to 500 bucks. Typically, the models that will be effective enough for day to day usage in family households will fall into this price band. Just watch out for extra fees and hidden costs like when a manufacturer doesn't include the lid and seat.

Wrapping up

The K-3979-96 is a solid choice if you're going for flush ratings alone. However, some people will rightly talk about the fact that it's not as economically friendly as 1.28 GPF options. On balance, we believe that the good points outweigh the bad, whilst remaining fairly inexpensive.

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