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Breville BOV450XL vs Mueller 4 Slice Toaster Oven Side-by-Side Comparison

Alan Nguyen
Reviewer
Nguyen Ntk
Visual Specialist
Updated
Tested Using Methodology v1.0
Updated Apr 3, 2023
Tested Using Methodology v1.0
Updated Apr 3, 2023
The front of a closed stainless steel Breville BOV450XL Mini Smart Toaster Oven on a white background.
The front of a closed stainless steel Mueller MT-175 4-Slice Countertop Toaster Oven on a white background.

Our Verdict

6.5
Overall Score
  • Performance (50%)
    6.8/10
  • Design (25%)
    6.4/10
  • Usability (25%)
    6.2/10
6.1
Overall Score
  • Performance (50%)
    7.0/10
  • Design (25%)
    5.3/10
  • Usability (25%)
    5.2/10

The contest between the Breville BOV450XL and the Mueller 4 Slice (MT-175) showcases the differences between our definitive best small toaster oven and our best value small pick. Even though the first one is more than twice the price of the first one, it provides some extra features on top of a good cooking performance.

Both toaster ovens have a high build quality shown in their thick casing for good heat insulation and overall sturdy structure. In addition to the standard three analog control dials, the Mueller has a detachable crumb tray that helps with cleaning the interior, which is usually tricky for small units. 

On the other hand, the Breville has a slide-out crumb tray and a non-stick interior for easy cleaning. Moreover, it has a digital display, precise timer and temperature control buttons, and extra toggle switches for internal lighting, frozen foods, and temperature conversion.

The Mueller’s performance was quite formidable, especially considering that it has a lower power output and less heating elements than the Breville. They were equal in toasting bread and roast whole chicken.

The Breville lost to the Mueller in baking pizza, but only because its cooking time was too long for our standard. Most importantly however, the Breville was able to improve upon a common weakness of small units—having a low power output for our baked frozen fries test.

Inconsistent Heating

Breville Mini Smart Toaster Oven Performance

Mueller 4-Slice Toaster Oven Performance: Good Heat Distribution
6.8
Performance Scores
  • Toast (40%)7.8/10
  • Pizza (25%)5.5/10
  • Whole Roasted Chicken (25%)6.6/10
  • Baked French Fries (10%)6.5/10
7.0
Performance Scores
  • Toast (40%)7.5/10
  • Pizza (25%)7.6/10
  • Whole Roasted Chicken (25%)7.0/10
  • Baked French Fries (10%)3.6/10
7.8

Toast

7.5
From left to right, 24 pieces of toast for the top and bottom of three toast levels including lighter, medium, and darker.
On the left: Level 3; In the middle: Level 4; On the right: Level 5
From left to right, 24 pieces of toast for the top and bottom of three toast levels including lighter, medium, and darker.
The top and bottom of the best four pieces of toast from the stainless steel Breville BOV450XL Mini Smart Toaster Oven.
On the left are the top and bottom of four pieces of toast from the first batch, and on the right are from the second batch.
Taste: 8
50% * 8 = 4.0
Even Surface Color: 8
20% * 8 = 1.6
Consecutive Usability: 7.5
30% * 7.5 = 2.3
  • Function: Toast
  • Number Of Slices: 4
  • Toast Level: 4/7
  • Cooking Time: 3m
  • Second Batch: 2m 36s
  • Convection: No

After following our Toast test procedures, we determined that this oven’s toasting level 4—3 minutes on the timer—was the best option, giving it a score of 7.9/10. At level 3, the bread was very lightly toasted and at 5 was darker than ideal and had a more uneven surface color.

At toast level 4, the Breville produced 4 pieces with mottled light golden to golden-brown color which looked quite appetizing. The color was not evenly distributed due to the oven’s lack of a convection system, though, so we gave it an 8/10.

The first batch of toast was nicely crispy outside while still soft and moist inside, deserving an 8/10 score for flavor. Our head chef, Tuyet Pham, determined they would go well with pretty much anything including an omelet, eggs benedict, and particularly sandwiches.

Even though the oven automatically adjusted the timer to 2 minutes 36 seconds, the color of the second batch was a bit darker. Also, the second batch was crispier than the first which made it more suitable for soup.

Overall, it’s a 7.5/10 for consecutive usability. Remember to reduce the heat by one level if you want the same result. Thanks to its high wattage, this oven has the fastest cooking time for toast among the toaster ovens we’ve tested thus far.

Mueller 4 Slice Toaster Oven Toast Test
From left to right, 24 pieces of toast for the top and bottom of three toast levels including lighter, medium, and darker.
The top and bottom of the best four pieces of toast from the stainless steel Mueller MT-175 4-Slice Countertop Toaster Oven.
On the left are the top and bottom of four pieces of toast from the first batch, and on the right are from the second batch.
Taste: 8
50% * 8 = 4.0
Even Surface Color: 7
20% * 7 = 1.4
Consecutive Usability: 7
30% * 7 = 2.1
  • Function: Toast
  • Number Of Slices: 4
  • Toast Level: ⅓ to Dark
  • Cooking Time: 4m
  • Second Batch: 4m
  • Convection: No

For our Toast test, we started off by trying the Medium Toast setting which was around 3 minutes 5 seconds on the timer. The four pieces of bread on the upper tray level came out only lightly toasted on top except for one golden brown piece. We then cranked it up to the Dark Toast setting—around 4 minutes 50 seconds on the timer—which, unfortunately, burnt the toast a bit.

Finally, we opted for the middle ground which was 4 minutes on the timer—⅓ of the rotation from Medium to Dark. This setting was tricky to get right on the time dial, so we used an external timer. It gave us the best possible toast results from this oven scoring a 7.5/10 in total.

After 4 minutes of toasting, the four pieces of toast had pretty good surface color. However, the colors varied from light golden to golden brown on both the top and the bottom, so we could only give a 7/10.

Luckily, the varied colors partially meant varied textures which were all good and deserving an 8/10. The golden brown areas had a more crispy outside while the light golden areas had a softer inside. Our head chef Tuyet Pham determined that it would go great with omelets, eggs benedict, and sandwiches but not so much with soup.

After taking out the first batch, we immediately put four more pieces inside to test the oven’s consecutive usability which ended up at 7/10. Also under the identical toasting time, the four pieces of bread became brown with an increased evenness from the first batch. While the color was a bit darker than ideal, the extra crispiness made the second batch more suitable for soups.

5.5

Pizza

7.6
A toaster oven baked 9-inch thick-crust meat pizza with cheese, onions, and green bell peppers on top inside a baking pan.
A toaster oven baked 9-inch thick-crust meat pizza with cheese, onions, and green bell peppers on top inside a baking pan.
Two slices of oven baked 9-inch thick-crust meat pizza with cheese, onions, and green bell peppers on top of one another.
Two hands break apart a slice of pizza with melty cheese, meat, and green bell peppers on top baked using a toaster oven.
Cooking Time: 0
20% * 0 = 0.0
Crust: 7
20% * 7 = 1.4
Toppings: 6.5
30% * 6.5 = 1.9
Taste: 7
30% * 7 = 2.1
  • Function:  Bake
  • Temperature: 450°F
  • Cooking Time: 10m 30s
  • Convection: No

The Breville oven did not agree with the 9-inch thick-crust meat pizza we tried to bake. We gave it a score of only 5.5/10.

This oven took 10m 30s to bake the pizza which was only slightly longer than the recommended 10 minutes on the label. However, 10 minutes was the time limit of our Pizza test, so it failed the cooking time section.

The crust had a nice golden color but was soft and dry—a possible consequence of the long cooking time. Therefore, we could only give it a 7/10.

The toppings were mostly dry with uneven color. Plus, the cheese wasn’t well melted, so it received a 6.5/10.

After tasting, our chef gave the pizza a 7/10.

Mueller 4 Slice Toaster Oven Pizza Test
 Mueller 4 Slice Toaster Oven PizzaA toaster oven baked 9-inch thick-crust meat pizza with cheese, onions, and green bell peppers on top inside a baking pan.
Two slices of oven baked 9-inch thick-crust meat pizza with cheese, onions, and green bell peppers on top of one another.
Two hands break apart a slice of pizza with cheese, meat, onions, and green bell peppers on top baked using a toaster oven.
Cooking Time: 6
20% * 6 = 1.2
Crust: 8
20% * 8 = 1.6
Toppings: 8
30% * 8 = 2.4
Taste: 8
30% * 8 = 2.4
  • Function: Toast
  • Temperature: 450°F
  • Cooking Time: 9m
  • Convection: No

For its low power draw, the Mueller did pretty well in our Pizza test with a score of 7.6/10.

The oven took 9 minutes to bake a 9-inch thick-crust meat pizza which was slightly faster than the label’s recommended 10 minutes. However, compared to our tested toaster ovens, it could only be a 6/10.

The crust had a golden color all the way through and the inside was still moist. If only the crust was a bit more crispy, it would’ve gotten higher than an 8/10.

The toppings were also caramelized quite evenly from the meat and veggies to the cheese, worthy of another 8/10. The cheese was nicely melted but the areas closer to the back of the cooking chamber were more caramelized compared to the rest.

With both the crust and the toppings being 8/10, our chef had no reason to give the pizza one final 8/10 for taste.

6.6

Whole Roasted Chicken

7.0
A whole roasted chicken using a toaster oven on an enamel baking pan on a white background.
A whole roasted chicken using a toaster oven on an enamel baking pan on a white background.
A tray of whole toaster oven roasted chicken. The thermometer has two probes inside the chicken and displays 168°F and 171°F.
Seven pieces of a carved chicken including a carcass, two breasts, two wings, and two thighs on an enamel baking pan.
The chicken thigh is slightly pink near the bone. In the white background is the rest of the roasted chicken on a baking pan.
Cooking Time: 7.5
20% * 7.5 = 1.5
Skin: 5.5
20% * 5.5 = 1.1
Doneness: 7
20% * 7 = 1.4
Taste: 6.5
40% * 6.5 = 2.6
  • Function: Bake
  • Temperature: 350°F
  • Cooking Time: 1h 5m
  • Convection: No

The Breville could barely fit the 3 lb chicken for our Whole Roasted Chicken test and scored a 6.9/10. The chicken grazed the safety guards that protect the upper heating elements while we were putting it in. During the roasting, quite a bit of grease splashed inside the oven and caused the heating elements to smoke a little.

The oven took 1h 5m to cook the chicken which was just 5 minutes longer than what we consider standard, so it got a 7.5/10.

After roasting, the skin had a quite even coloring although a bit too light, and remained soft. We awarded it a 7/10. In addition, the skin on the back got stuck to the baking pan during roasting.

The chicken’s internal temperature was 168-171°F which was very close to the USDA recommendation. However, there were a few pink spots near the bone, so we gave it a 7/10.

Even though the meat was juicy, the unappetizing chicken skin was enough that our chef lowered the score to 6.5/10 for taste.

Mueller 4 Slice Toaster Oven Whole Roasted Chicken Test
A whole roasted chicken using the Mueller MT-175 Toaster Oven backside up on a silver baking pan on a white background.
A whole roasted chicken using the Mueller MT-175 Toaster Oven belly up on a silver baking pan on a white background.
A tray of whole toaster oven roasted chicken. The thermometer has two probes inside the chicken and displays 185°F and 192°F.
Eight pieces of a carved chicken including two carcass halves, two breasts, two wings, and two thighs on a baking pan.
Two hands pulling apart a roasted chicken thigh. In the white background is the rest of the roasted chicken on a baking pan.
Cooking Time: 6
20% * 6 = 1.2
Skin: 5.5
20% * 5.5 = 1.1
Doneness: 8.7
20% * 8.7 = 1.7
Taste: 7.5
40% * 7.5 = 3.0
  • Function: Toast
  • Temperature: 350°F
  • Cooking Time: 1h 20m
  • Convection: No

The Mueller could barely fit a 3 lb chicken for our Whole Roasted Chicken test. Nonetheless, the result was quite decent at 7/10 in total. If you were to purchase this oven and use it to roast a whole chicken, we recommend cutting it open or chopping it into pieces beforehand.

We first placed the chicken backside down on the baking pan. When we slid the pan in, the top of the chicken breast grazed the upper heating element’s guard and was seared.

After the first 40 minutes, we flipped the chicken to find out that parts of the skin on the back got stuck to the baking pan. Then, when we reinsert the pan, the same problem with the breast happened to the back. Luckily, they weren’t burnt.

However, even after 1 hour and 20 minutes, most of the chicken skin still hasn’t reached a desirable color. The chicken, for the most part, looked like it was steamed and not roasted, so we gave the skin a 5.5/10.

Nonetheless, our chef decided to stop the roasting as the color wouldn’t improve anyway and to avoid overcooking the meat. This cooking time was the equivalent of a 6/10 according to our data.

With such a long cooking time, the meat had no pink spots. However, the chicken’s internal temperature was 185°F-192°F, higher than the USDA recommended 165°F-180°F. Thus, we gave it an 8.7/ for doneness.

While not the most appetizing looking, the meat was very juicy. That, combined with the slight caramelization on the skin, was enough for a 7.5/10 for taste from our chef.

6.5

Baked French Fries

3.6
Pieces of baked french fries using a toaster oven on an enamel baking pan on a white background.
Pieces of baked french fries using a toaster oven on an enamel baking pan on a white background.
A close-up of pieces of baked french fries using a toaster oven on an enamel baking pan on a white background.
Six pieces of broken-up baked french fries are stacked on top of pieces of whole fries on an enamel baking pan.
Cooking Time: 5
20% * 5 = 1.0
Color: 7
20% * 7 = 1.4
Texture: 6.5
20% * 6.5 = 1.3
Taste: 7
40% * 7 = 2.8
  • Function: Bake
  • Temperature: 400°F.
  • Cooking Time: 25 m
  • Convection: No

The Breville did an acceptable job of baking 12 oz of french fries, scoring a 6.5/10.

It took 25 minutes, the limit of our Baked French Fries test, so this oven got a 5/10.

Except for a few golden pieces, the fries mostly lacked color. They only deserved a score of  7/10.

The fries had a variety of textures, none of which were good. The golden fries were dry and yet only slightly crispy. Also, the ones that lacked color were really soft, so it was only a 6.5/10.

Our chef gave the fries a 7/10 for taste.

Mueller 4 Slice Toaster Oven Baked French Fries Test
Mueller 4 Slice Toaster Oven Baked French FriesPieces of baked french fries using the Mueller MT-175 Toaster Oven on a grooved silver baking pan on a white background.
A close-up of pieces of baked french fries using the Mueller MT-175 Toaster Oven on a baking pan on a white background.
Ten pieces of broken-up baked french fries are stacked on top of pieces of whole fries on a grooved silver baking pan.
Cooking Time: 0
20% * 0 = 0.0
Color: 4.5
20% * 4.5 = 0.9
Texture: 4.5
20% * 4.5 = 0.9
Taste: 4.5
40% * 4.5 = 1.8
  • Function: Toast
  • Temperature: 400°F
  • Cooking Time: 27 m
  • Convection: No

Our Baked French Fries test brought out the Mueller’s weakness of not being able to maintain a high temperature due to its low power draw. Its even heat distribution couldn’t help much if the temperature wasn’t high enough, so the final score was 3.6/10.

We stopped the baking after 27 minutes as the fries weren’t getting any more colors. This, nonetheless, was over our time limit of 25 minutes, so it was a 0/10.

The fries had no significant color change and barely enough for a 4.5/10. We ended up with 12 oz of frozen fries that were more similar to being dried in an oven than being baked, so we gave them another 4.5/10 for texture.

Fortunately, the fries were cooked through and not soggy, so our chef could give them a 4.5/10 for taste and not a zero.

Can Be Improved With a Convection System

Breville BOV450XL Design

Stainless Steel Mueller 4-Slice Toaster Oven Design Review: Standard
6.4
design Scores
  • Exterior (20%)6.0/10
  • Interior (30%)4.0/10
  • Build Quality (50%)8.0/10
5.3
design Scores
  • Exterior (20%)5.0/10
  • Interior (30%)1.0/10
  • Build Quality (50%)8.0/10

In the Breville BOV450XL Mini Smart Toaster Oven Box

In the Mueller MT-175 Small Toaster Oven Box
An oven rack, 5 pieces of document, the Breville BOV450XL Mini Smart Toaster Oven, a box, and an enamel baking pan.
  • Model: BOV450XL
  • Warranty: 1-year limited
  • User Manual
  • Baking Rack
  • Baking Pan

On the packaging were some illustrations and basic information, and the oven was couched nicely between two foam pads. Breville’s user manual explains in detail how each oven function works. 

The default accessories, a baking rack and baking pan, were packaged in a fitted carton box. You can opt to buy a separate 11” pizza pan and/or a broiling rack to cover more cooking methods.

A box, the Mueller MT-175 4-Slice Toaster Oven, a recipe booklet, a baking pan, an oven rack, a user manual, and a brochure.
  • Model: MT-175
  • Warranty: 1 year
  • User Manual
  • Baking Rack
  • Baking Pan

The Mueller toaster oven came in a basic packaging and positioned with two foam pads. The included accessories were simply duct-taped to the oven. Inside the box are also a user manual and a simple recipe booklet.

6.0

Exterior

5.0
A closed front of the Breville BOV450XL Mini Smart Toaster Oven with exterior measurements on a white background
A closed front of the Breville BOV450XL Mini Smart Toaster Oven with exterior measurements on a white background
The front of a closed stainless steel Breville BOV450XL Mini Smart Toaster Oven has a control panel and the right has holes.
The back and left sides of the Breville BOV450XL Toaster Oven have holes. The back has a power cord and two buffers.
The top of the stainless steel Breville BOV450XL Mini Smart Toaster Oven on a grey background.
On a grey background, the bottom of the stainless steel Breville BOV450XL Mini Smart Toaster Oven has four stands and holes.
View from the top onto a slide-out crumb tray of the Breville BOV450XL Mini Smart Toaster Oven on a grey background.
  • Weight:
    10.0 lbs (4.5 kg)
  • Length:
    15.7" (40.0 cm)
  • Width:
    14.2" (36.0 cm)
  • Height:
    8.9" (22.5 cm)
  • Material:
    Stainless steel
  • Color:
    Silver
  • Door Handle:
    cool-touch
  • Tray Indicators:
    Yes
  • Crumb Tray:
    Slide-out

The small size didn’t stop Breville from designing a sturdy stainless steel outer shell. The shape of the back buffers makes it easy to wrap the power cord around them once things have cooled.

Also, the tray-level indicators on the glass door and the slide-out crumb tray are always nice touches. However, the oven’s exterior doesn’t provide good grip points to carry the oven.

We measured the oven’s footprint to be 15.74" x 14.17" x 8.86" which was slightly different in terms of height from the manufacturer’s 16.1" x 14.2" x 10.4".

A closed front of the stainless steel Mueller MT-175 4-Slice Toaster Oven with exterior measurements on a white background.
A closed front of the stainless steel Mueller MT-175 4-Slice Toaster Oven with exterior measurements on a white background.
Mueller 4 Slice Toaster Oven ExteriorThe front of a closed stainless steel Mueller MT-175 4-Slice Toaster Oven has a control panel and the right has holes.
The back and left sides of the Instant Omni Plus 18L have air ventilation holes. The back has a power cord and two buffers.
The top, front, and right sides of the Black+Decker TO1760SS 4-Slice Natural Convection Toaster Oven on a white background.
On a white background, the bottom of the Mueller MT-175 Toaster Oven has a detachable crumb tray, four stands, and holes.
The detached crumb tray of the stainless steel Black+Decker TO1760SS 4-Slice Countertop Toaster Oven on a white background.
  • Weight:
    9.0 lbs (4.1 kg)
  • Length:
    15.0" (38.0 cm)
  • Width:
    11.6" (29.5 cm)
  • Height:
    8.9" (22.5 cm)
  • Material:
    Stainless steel
  • Color:
    Gray
  • Door Handle:
    Cool-touch
  • Tray Indicators:
    No
  • Crumb Tray:
    Detachable

As simple as it is, the Mueller has all the standard exterior features of a small toaster oven but also something more. The bottom of the oven acts as a detachable crumb tray which not only makes it easy to remove the falling bits and crumbs but also to clean the entire interior.

The oven has a cool-touch door handle and back buffers to prevent it from being too close to the wall. Unfortunately, it has no cord storage or carrying handles.

Our measurements of the oven’s footprint were 14.96" x 11.61" x 8.86" which pretty much coincided with the manufacturer’s 14.84" x 11.85" x 8.86". However, the weight of the oven by itself was already 9 lbs whereas the label said the entire box was 7.63 lbs.

Control Panel

Control Panel of the Small Mueller MT-175
The Breville BOV450XL Mini Smart Toaster Oven’s control panel has an LCD, 1 cooking functions’ control dial, and 8 buttons
  • Type:
     LCD display + 1 control dial + 8 buttons
  • Temperature:
    120°F - 450°F
  • Timer:
    1 minute - 2 hours
  • Indicator Light:
    No
  • Status Bar:
    No
  • Light Toggle:
    No
  • Convection Toggle:
    No
  • Rotation Toggle:
    No
  • Automatic Preheat:
    Yes
  • Audio Cues:
    No

The control panel consists of 1 control knob for 8 functions and 4 buttons to set the time, temperature, and/or toasting mode. The digital display and the Start/Cancel button both shine blue when the oven’s plugged in and red when it’s cooking.

Beyond the standard stuff, you’ll find 3 unique buttons: Temperature Conversion (°F-°C), Frozen Foods, and A Bit More. The latter adds a specific amount of time depending on the cooking function.

The LCD screen will display ‘E01’ or ‘E02’ when there is a non-resettable issue with the appliance. When this happens, immediately unplug the cord from the wall outlet and call the Breville Customer Service Center.

The ‘E03’ shows up when the oven temperature exceeds its design limit. Should this occur, unplug your oven, allow it to cool for 15 minutes, then plug it back in.

The ‘E04’ appears when the room temperature is below the set minimum. If this happens, unplug the oven and move it to a warmer area.

The control panel of the Black+Decker TO1760SS 4-Slice Toaster Oven has 3 control knobs for temperature, function, and timer.
  • Type:
    3 control knobs
  • Temperature:
    150°F - 450°F
  • Timer:
    1 minute - 30 minutes + stay-on
  • Indicator Light:
    Yes
  • Status Bar:
    No
  • Light Toggle:
    No
  • Convection Toggle:
    No
  • Rotation Toggle:
    No
  • Automatic Preheat:
    No
  • Audio Cues:
    No

The Mueller has a basic analog control panel with three dials for temperature, function, and time. The time dial has a stay-on setting to help with its short range, similar to many other small toaster ovens. Interestingly, while the max temperature setting was 450°F, we actually recorded the internal temperature of the oven reaching 500°F on the said setting.

Cooking Functions of the Breville BOV450XL Smart Toaster Oven

Cooking Functions
  • Toast (7 levels, 4 slices maximum)
  • Bagel (7 levels, 4 slices maximum)
  • Bake (1h 30m maximum)
  • Broil (High and Low levels, 20 minutes maximum)
  • Pizza (55 minutes maximum)
  • Roast (1h 30m maximum)
  • Cookies (55 minutes maximum)
  • Reheat (370°F maximum)

For safety reasons, all cooking functions have a predetermined timer limit after which the oven stops cooking. If you want to continue cooking, simply operate the oven in standard mode. The High setting of the Broil function does the job faster than Low and you’ll need to experiment with it to learn how quickly it cooks.

The function dial of the Black+Decker TO1760SS 4-Slice Toaster Oven has 3 cooking functions including Bake, Broil, and Toast.
  • Toast
  • Bake
  • Broil
  • Keep warm

Different from most other toaster ovens, the Mueller’s Bake function only uses the lower heating elements as opposed to lower and upper. The Broil function still uses only the upper heating elements.

The Toast function is where both the lower and upper heating elements work. Nonetheless, the oven still provides all the basic functions for its intended purposes.

4.0

Interior

1.0
The Breville BOV450XL ’s cooking chamber is black and has 4 quartz heating elements with guards and 2 guide rails.
The Breville BOV450XL ’s cooking chamber is black and has 4 quartz heating elements with guards and 2 guide rails.
The cooking chamber’s right wall of the Breville BOV450XL has 2 guide rails.
  • Heating Elements:
    4 quartz
  • Convection Fan:
    No
  • Lighting:
    No
  • Tray Levels:
    3
  • Rotisserie:
    No
  • Safety Hook:
    No

The Breville’s interior has a non-stick coating, 4 heating elements, and 3 tray levels (quite rare for its size). However, it has no internal lighting or convection system.

The oven uses 4 quartz heating elements, each with its own safety guard to prevent direct contact with baking pans and food. Unlike the more common nichrome style, these don’t heat the air in the oven, but rather radiate the infrared heat directly to the food or pan.

Overall, they produce more heat and cool down faster than nichrome. In addition, they’re easier to clean and are more energy-efficient but not as durable. However, if grease splashes onto the heating elements while cooking, it’ll leave permanent stains.

Mueller 4 Slice Toaster Oven InteriorThe Mueller MT-175 4-Slice Toaster Oven’s cooking chamber has 2 quartz heating elements with guards and 2 guide rails.
Mueller 4 Slice Toaster Oven InteriorThe Mueller MT-175 4-Slice Toaster Oven’s cooking chamber has 2 quartz heating elements with guards and 2 guide rails.
The Mueller MT-175 Oven has 1 bottom heating element with a guard and 2 guide rails on its right cooking chamber wall.
  • Heating Elements:
    2 quartz
  • Convection Fan:
    No
  • Lighting:
    No
  • Tray Levels:
    2
  • Rotisserie:
    No
  • Safety Hook:
    No

Similar to many other small toaster ovens, including the Comfee CFO-BB101, the Mueller lacks a convection fan and an interior light. In addition, it only has two heating elements which can usually lead to uneven heat distribution compared to four or more heating elements.

These heating elements are made of quartz which uses infrared light to cook foods faster than the more common nichrome counterparts. Quartz heating elements also cool down faster, are more energy-efficient and easier to clean but not as durable.

However, if grease splashes onto the heating elements while cooking, it’ll leave permanent stains. This is why they usually have guards which this oven also has.

Capacity of the Breville Smart Toaster Oven

Capacity of the Mueller 4-Slice Toaster Oven
An opened front of the Breville BOV450XL Mini Smart Toaster Oven with interior measurements on a white background.
  • Length:
    11.5" (29.2 cm)
  • Width:
    11.0" (27.9 cm)
  • Height:
    6.7" (17.0 cm)

The BOV450XL had enough space for four slices of toast, an 11-inch pizza, or barely a 3 lb whole chicken.

We measured the cooking chamber’s volume to be 13.86 liters compared to the manufacturer’s provided capacity of 12.74 liters. However, it could just be because we measured from the cooking chamber’s walls to walls whereas the manufacturer stopped before reaching the heating elements.

An opened front of the stainless steel Mueller MT-175 4-Slice Toaster Oven with interior measurements on a white background.
  • Length:
    10.6" (27.0 cm)
  • Width:
    9.8" (25.0 cm)
  • Height:
    7.5" (19.0 cm)

We could fit four slices of toast, a 9-inch pizza but we could barely fit a 3 lb chicken inside the Mueller, unlike the same-sized Breville BOV450XL. We measured the cooking chamber volume to be around 12.81 liters, slightly different than the manufacturer’s provided capacity of 11.67 liters. However, it could just be a difference in measuring standards.

Power Cord

A three-pronged plug power cord. In the background is the stainless steel Breville BOV450XL Mini Smart Toaster Oven.
  • Length:
    40.9" (104.0 cm)
  • Type:
    3-prong plug
  • Power:
    1800 W
  • Rated Output:
    110 V - 120 V ~ 60 Hz

The power cord is roughly 40.94"—plenty of length for household use—and can be wrapped around the back buffers for storage. The plug also has a nice little handle which makes it easier to grab.

A two-pronged plug power cord. In the background is the stainless steel Mueller MT-175 4-Slice Countertop Toaster Oven.
  • Length:
    30.7" (78.0 cm)
  • Type:
    2-prong plug
  • Power:
    1100 W
  • Rated Output:
    120 V ~ 60 Hz

The power cord is 30.7 inches long, suitable for household use. Unfortunately, the oven doesn’t have any storage space for it.

Baking Rack

Accessories

Baking Rack
A stainless steel baking rack of the stainless steel Breville BOV450XL Mini Smart Toaster Oven on a grey background.
  • Length:
    11.5" (29.2 cm)
  • Width:
    10.3" (26.3 cm)
  • Height:
    0.3" (0.7 cm)
  • Material:
    Stainless steel
  • Dishwasher Safe:
    Yes

The rack fits perfectly on the guide rails, which helps prevent accidents when placing your food in the oven.

A stainless steel baking rack of the Mueller MT-175 4-Slice Countertop Toaster Oven on a white background.
  • Length:
    10.5" (26.7 cm)
  • Width:
    8.8" (22.4 cm)
  • Height:
    0.5" (1.3 cm)
  • Material:
    Stainless steel
  • Dishwasher Safe:
    Yes

The two sides of the baking rack have slight curves upward at an angle to keep the baking pan in place. It fits perfectly with the guide to help prevent accidents when placing your food in the oven.

Baking Pan

Accessories

Baking Pan
A enamel baking pan of the stainless steel Breville BOV450XL Mini Smart Toaster Oven on a grey background.
  • Length:
    10.6" (27.0 cm)
  • Width:
    10.6" (27.0 cm)
  • Height:
    1.2" (3.0 cm)
  • Material:
    Stainless steel with enamel coating
  • Dishwasher Safe:
    Not advisable

Although the baking pan is a bit smaller than the rack, it still has more than enough space for a 3 lb chicken. Thus, it keeps most of the mess off the heating elements. 

However, even with the enamel coating, the chicken skin still stuck to the pan during our roasting test. Also worth noting is that the dishwasher can damage this coating.

A grooved silver baking pan of the stainless steel Mueller MT-175 4-Slice Countertop Toaster Oven on a white background.
  • Length:
    10.2" (25.8 cm)
  • Width:
    7.9" (20.0 cm)
  • Height:
    0.6" (1.5 cm)
  • Material:
    Stainless steel
  • Dishwasher Safe:
    Yes

The baking pan doesn’t fit into the guide rails and has to on top of the rack. This may prevent the full use of the oven’s capacity and lead to some inconveniences during cooking.

On the bright side, the pan has ridges and grooves to give your food attractive roasting marks and catch the dripping better. It has a coating but is not completely non-stick so you may need to watch out for some stubborn stains after a hefty roast.

8.0

Build Quality

8.0
The front of an opened stainless steel Breville BOV450XL Mini Smart Toaster Oven with a baking rack and a baking pan.

The Breville is well-constructed and durable with a high power rating of 1800 W. All of its parts fit nicely and work smoothly, especially the LCD display and the buttons.

Thanks to the good insulation of the casing, the oven gets hot to the touch only after cooking for a long period of time at high heat.

The front of an opened stainless steel Mueller MT-175 4-Slice Countertop Toaster Oven with an oven rack and baking pan.

For a simple small toaster oven, build quality is all about how durable it is and if it works properly. The Mueller accomplishes that with a sturdy stainless steel casing and smooth-turning dials.

Flawed Technology

Breville Mini Toaster Oven Usability Review

Muller 4-Slice Toaster Oven Usability: Easy but Not Convenient to Use
6.2
usability Scores
  • User Control (30%)8.0/10
  • Ease of Use (50%)4.0/10
  • Cleanability (20%)9.0/10
5.2
usability Scores
  • User Control (30%)6.0/10
  • Ease of Use (50%)4.0/10
  • Cleanability (20%)7.0/10
8.0

User Control

6.0

The Temperature Conversion button is a nice touch for international users. The cooking time can be adjusted in increments of 1 minute and the temperature in increments of 5°F. For some reason, this differs from what the user manual states.

The manual says that the FROZEN FOODS button adds the right amount of additional time needed to defrost the target foods in the Toast, Bagel, Pizza, Cookies, and Bake functions. However, we didn’t find it very useful since cooking time depends heavily on the food quantity and personal preference.

The A BIT MORE button, where each press adds a pre-set amount of time to each function, has a similar problem. It only seemed useful when the oven was still cold and we wanted to skip the preheating phase.

Even though the Mueller only has three simple control dials, there are a few things to keep in mind. For the timer knob, when setting it to less than 10 minutes, always rotate past 10 minutes and then rotate back to the desired time.

It’s always tricky to precisely adjust time and temperature for an analog-control toaster oven and this one is no different. Nonetheless, you can use an external timer and an oven thermometer to get more accurate readings.

If you frequently use the stay-on feature, you can turn off the oven by rotating the function dial to Off instead of the timer.

4.0

Ease of Use

4.0

The Breville has an automatic preheating phase that lasts 1m 45s. Our tests saw it reaching around 180°F in that time. The temperature alert will sound when the oven reaches your selected temperature. Then, it will sound three times at the end of the cooking cycle.

It’s very easy to adjust cooking settings during use, especially compared to an analog unit like the Mueller MT-175. However, even though this oven doesn’t turn off upon opening the door, the door won’t stay partially open – it’s all or nothing.

According to the manufacturer, the Element iQ System’s smart algorithms focus power where and when it’s most needed, creating ideal cooking conditions every time. However, we didn’t notice a significant difference in performance when comparing it to other ovens of the same size/wattage.

If it’s not actively cooking, the oven will go into STANDBY mode after 10 minutes with no interaction. Although unplugging the oven resets your customized setting, Breville recommends doing so anyway after you finish using it.

What’s convenient about 100% analog toaster ovens is that it’s very simple to adjust time and temperature during cooking. When the timer runs out, a bell will sound and the oven will shut off. Afterward, you can freely leave it plugged in and not worry about power consumption as it has no digital display.

The door can open at any angle < 50° to let food cool down inside the oven. However, keep in mind that opening the door doesn’t stop the oven. The exterior shell isn’t very thick, so it gets hot to the touch quite quickly during cooking.

9.0

Cleanability

7.0
Grease on the back of the stainless steel Breville BOV450XL Mini Smart Toaster Oven’s glass door.
Grease on the back of the stainless steel Breville BOV450XL Mini Smart Toaster Oven’s glass door.
Brushing the upper heating element’s guards of the stainless steel Breville BOV450XL Mini Smart Toaster Oven’s glass door.
Grease and chicken skin stuck on the enamel baking pan of the stainless steel Breville BOV450XL Mini Smart Toaster Oven.
The cleaned enamel baking pan of the stainless steel Breville BOV450XL Mini Smart Toaster Oven.

We cleaned the Breville in accordance with our toaster oven cleaning guide. Thanks to the stainless steel exterior and non-stick interior, it was very easy to clean. Removing crumbs was also easy thanks to the slide-out crumb tray, although we still had to tilt the oven to get the last of them out.

The upper heating elements got stained by smoke from splattered grease during our roasted chicken test. Fortunately, we had no problem removing the stains by brushing the elements with a paste of baking soda and water. We were also able to easily scrub the burnt chicken skin off of the baking pan.

Mueller 4 Slice Toaster Oven CleanabilityPermanent stains on the left cooking chamber’s ceiling and the upper heating element’s guard of the Mueller MT-175 Oven.
Mueller 4 Slice Toaster Oven CleanabilityPermanent stains on the left cooking chamber’s ceiling and the upper heating element’s guard of the Mueller MT-175 Oven.
Permanent stains on the right cooking chamber’s ceiling and the upper heating element’s guard of the Mueller MT-175 Oven.
The cleaned grooved silver baking pan of the stainless steel Mueller MT-175 4-Slice Countertop Toaster Oven.

We clean the stainless steel exterior with no problem. However, after the chicken test, there were burnt bits stuck to the upper heating element’s guard and grease on the cooking chamber’s ceiling. There was ample space between the ceiling and the upper heating element, so we proceed to try every cleaning method possible.

Unfortunately, we could only scrub off the bits. Due to the interior not having a non-stick coating, there were some permanent stains on the cooking chamber’s ceiling and the upper heating element’s guard.

Luckily, the heating element itself was intact. Also, we were able to remove the stubborn stains on the baking pan by brushing them with a paste of baking soda and water.