Is the Kirby Sentria really the best model of Kirby vacuums? Is it worth the hundreds of dollars more than a previous model? For your money what is the best model of kirby for you to own? This guide will answer all of those questions and more. This guide will cover the differences between models of Gsix through the Sentria model. It will give you the information you need to buy the best Kirby model.

Kirby Vacuums is one of our most popular selling vacuums. As a result we get lots of emails from customers asking which model is the best model for their needs. This article is a response to hopefully help you pick the correct Kirby for your needs.

Keep in mind that I will try to include as many facts as I can, but that a lot of the information will be my thoughts and opinions. This article does not include the actual Kirby Specs or Kirby Domestic Specifications for all models. If you want that information please contact your local Kirby Dealer. This article is more of what I have personally noticed about the different models. At the end of the article I will make some suggestions that I think are the best Kirbys for the money and the best Kirby model ever made. So lets get started.

About every 3 years Kirby comes out with a new model. The current Model, which came out in 2006 is the Kirby Sentria, prior to that was the Kirby Ultimate Diamond, then before that the new model was the Ultimate G, then the Gsix. In this article we are going to talk about those models. Assuming a 3 year life before the next model came out that represents around 12 years of Kirby vacuums.

Keep in mind owning even a 15 or 20 year old Kirby is not that bad. Most plastic junk you buy at the big box stores have a shelf life of around 3 to 5 years (depending on model you buy). In fact Kirby home care systems are rated #1 in reliability by a popular consumer products magazine. We have seen an average life on a Kirby vacuum of 25 years (on average, we have seen tons of Kirby vacuums that are 40+ years that run fine). So if you were buying a plastic vacuum that lasted on average 3 years I would suggest getting the newest model, but when you have a 25 year average life span owning the newest model is not essential.

So lets get to it. Lets go over the differences in these Kirby models.

So for this test I pulled out our 4 different models and flipped them upside down and read their model tags. This is what they said. POWER - (this is a perfect example of how Kirbys are the most powerful vacuum but don't have huge amp motors)

Gsix = 7 AMP 50-60 Hz
Ultimate G= 7 AMP 50-60 Hz
Diamond = 7 AMP 50-60 Hz
Sentria = 7 AMP 50-60 Hz

In other words according to the model tag on the vacuum all these kirbys use the same motor size and power.

FILTRATION - for filtration ratings I checked the Kirby bags and looked up ratings online.

Gsix = HEPA filtration filters from .3 to .1 microns
Ultimate G = HEPA filtration filters from .3 to .1 microns
Diamond = HEPA filtration filters from .3 to .1 microns
Sentria = HEPA filtration filters from .3 to .1 microns

Also on the above models I checked the inner fill tube and mini emptor (channels air flow from fan chamber to inner fill tube) and besides color I saw no differences. All models can use the same disposable bag.


Models Gsix, Ultimate G, Diamond and Sentria all use the same kevlar fan. The part number for the fan kit that we order that fits all those models is the same part number and fan kit.

TRANSMISSION - For the transmission I took each vacuum apart and read the part number stamped on each transmission.

Part #'s I saw stamped on each Kirby Vacuum Transmission are below for Kirby Transmissions.

Gsix = CA 550289
Ultimate G = CA 550289
Diamond = CA 550289
Sentria = CA 550289

That part number was stamped on all the transmissions. In other words the same Transmission part number.


I got an email from a Kirby owner who had a Kirby dealer give him the following information. The dealer had given his the "Domestic Specifications" for the Kirby Ultimate G and Sentria. If I ever get the ones for the Gsix and Ultimate Diamond I will post them here as well. I have posted some of these Specs below :

Sentria Maximum Airflow = 115 CFM
Ultimate G Maximum Airflow = 109 CFM

Maximum Suction for Sentria = 27.5 Inches of Water
Maximum Suction for Ultimate G = 26 Inches of Water

Maximum Motor Speed Sentria = 13000 RMP
Maximum Motor Speed Ultimate G = 12,400 RPM

I can't verify that information but it looks like these are the specs from Kirby. From looking at the vacuums and the model tags it looks to me like they have the same motor but if you look at the Motor Speed RPM it looks like they cranked up the speed on the Sentria and that may have given it the extra power. Thank you for the information that was emailed to us. If you have additional information we would be glad to post it here. Now lets cover a few items that are different.


Below is a picture of the Gsix Brushroll

Kirby Vacuum Brushroll

Below is a picture of the brushroll in Ultimate G, Diamond and Sentria

Kirby Vacuum Brushroll

In talking to some Kirby salesmen they claimed the Gsix brushroll cleaned dirt better, but when we tested it we did not see a difference. The brushroll on the Ultimate G, Diamond and Sentria also was stiffer and did a better job at sweeping up the carpet and did a better job on pet hair. When we are reconditioning a Gsix and have to replace the brushroll we always upgrade it to the new style of brushroll.


Below is a picture of each of the models. As you can see most of the look changes are with color. I will list the specific changes we noticed besides color. I probably wont include all the changes but will try and get most of them.

Gsix -

Kirby Vacuum

Ultimate G - The only difference I saw from the Gsix was color and the bag pattern was different. Also the HEPA bag material was thinner on the outer cloth bag. I have had customers email me and say they liked the Gsix material better (thicker) but we have seen no problems with the newer HEPA filtration material.

Kirby Vacuum

Diamond - Color is the same as the Ultimate G but the bag design has been changed to a diamond pattern. They also added a 2 speed switch. The switch is for delicate vacuuming. For example most vacuums don't have the power to actually pick up a carpet mat, the Kirby does. So at my house we have a lot of hardwood. Its kind of annoying to vacuum the rug because it actually picks it up. With the Diamond you just turn the switch down for delicate vacuuming or dusting.

Kirby Sentria

Sentria - There are quite a few look changes on this model. The really did a good job of trying to modernize it. They added a halogen light bulb (never supposed to burn out) and they got rid of the 2 speed switch. So as far as performance it will be similar to the Ultimate G and Gsix (see domestic specifications above). They modernized this model but ended up making some parts weaker (IMHO) which I will cover later. As far as look changes they redesigned the some of the tools like the upholstery tool, hand held tool and air flow tool. They also changed the look and design of the bumper. The 2 changes I did not approve of were the look and design of the belt lifter, turning knob and the handle. Some parts appear to be made weaker (which I will cover below).

Kirby Sentria

Those are basically all of the differences that I could see. I am sure there is some technical point I may have missed and I am not saying I have mentioned all the differences. I believe if the Kirby manufacturing plant had to change all their parts every 3 years they would go out of business. So at least these models use most of the same parts and have the similar performance. This is actually a good thing because parts will remain affordable to you the customer. When the new Sentria came out I read the article put out by Kirby that was going over all the new and exciting changes. I did not see any remarks in the article saying how the vacuum has better performance than the previous model. Most of the changes were mostly looks and design (except for the new light).

So in conclusion these are my suggestions:

1. For the money I personally beleive the best buy is the Kirby Gsix. It has the same performance as the newer models at a much lower price.

2. If you have lots of pet hair I would go with the Ultimate G or newer. Or you can get the Gsix but you will probably want to buy the newer style brushroll which we sell.

3. If you are not on a strict budget I personally believe that the best Kirby ever made was the Diamond Kirby for the following reasons.

a. First it is the newest model (made up to 2006) where it had all the best features without having the Sentria weakness's (i.e. weaker handle, mentioned below)
b. It is the only model of Kirby to have the 2 speed motor.

4. If you want the newest and coolest looking model of Kirby go with the Sentria. From the Specs sent to us, apparently it has a little more airflow as well.

I promised you above I would go over a couple of the things I don't like about the Sentria model.

1. The new parts that are on the Sentria will not be available to Shops like us for about another 2 years. So you would have to get those parts from Kirby, however, it shouldn't be a problem getting the parts (just get from your local dealer or kirby direct) but they will be a little more expensive and harder to find online. Examples of some of those parts would be the light, handle, bumper, belt lifter knob, tools, etc.

2. The handle being weaker (IMHO). On the Sentrias that we have sold we have had to pack the handles a lot better than previous models. All the previous models were metal framed with a plastic back handle cover (very strong) and on the Sentria it's plastic framed with some really light aluminum plating on the front. We had problems with those handles breaking in shipping so we had to pack them better. In talking to Kirby dealers we know they said the same thing. What makes Kirby models popular is power and durability. So I was disappointed with that.

Well that's it. I hope this review was helpful in making your decision on the best Kirby model. I hope I have made myself clear, have stated the facts well and you feel educated.

Thank You, 

Dustin Chaffin
Great-Vacs Manager

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