Mizuno ST-G 440 (2023) Driver Review

The Mizuno ST-G is a compact 440cc, ultra-low spin driver. Thanks to 14g of weight adjustability it can be set-up as a low spin bomber, draw/fade biased or simply a more stable smaller headed driver.

Over the last few years Mizuno have quietly built a reputation for making some of the fastest, most powerful drivers on the market. With the new ultra-low spin Mizuno ST-G driver they’re looking to ramp things up to a whole new level and build on that trend. Mizuno though have never really racked up tons of tour wins with their drivers. Which historically has come down to the brand being overlooked in favour of more lucrative contracts from the games major wood manufacturers.

Over the last few years though the company has found a new dedication to only producing drivers that compete alongside the very best. Plus there’s been a switch in strategy towards looking after younger players. Those who are more grateful for the brands help, and the move is starting to bare fruit in terms of additional tour usage.

With the brands models ranking among some of the best drivers we’ve tested over the last few years, the new ST-G sits alongside the forgiving ST-Z, and slightly draw biased ST-X. This is Mizuno’s compact, adjustable driver. Thanks to that adjustability the ST-G can be anything from a best low spin driver, for players who like to bomb it off the tee. To a fade/draw biased model or simply the most forgiving driver at a compact size.

Here’s what else you need to know.

Everything you need to know about the Mizuno ST-G 440 (2023) driver

The chamber of secrets

Mizuno’s CORTECH chamber has been really well received on previous driver launches (the ST-Z and ST-X). It’s no surprise then the tech makes an appearance again on the ST-G. Behind the face a chamber is filled with elastomeric TPU, with a stainless-steel weight suspended right in the center.

Mizuno say the idea allows stress from clubface flex to be transferred into an additional ball speed energy source. Just part of the reason why golfers generally get excellent speed and distance performance from modern Mizuno drivers. By moving the unit closer to the face, this generation reduces spin, whilst creating a solid, powerful impact sound and feel.   

Fast Track to adjustability

Over the years different Mizuno drivers have dabbled with adjustable weight technology. Recently though the brand have favoured weight tracks that allow golfers to dial in multiple set-ups from a single head. A trick that’s incredibly difficult to pull off efficiently.

Don’t be under any illusion the ST-G driver is a forgiving model, with a 440cc sized head it can never fulfil that role. Although it’s great having sliding mass for personalised performance, 14g split between two weights really isn’t huge amounts. If you’re attracted to smaller, more compact drivers the ability to dial in even less spin (weight forward), more forgiveness (weight back), or a draw/fade tendency will be beneficial to some.

A players profile

If modern wide, stable driver heads are your thing the ST-G isn’t for you. Expect instead a traditional pear shape model, much like the Titleist TSR 3. At address the face sits very square to the target, and to ensure versatility in both directions there’s also a very neutral weight set-up inside.

New materials – new results

Titanium drivers have been on the scene for decades but golf club engineers are constantly working on new Ti variations to better suit different locations within the driver head.

The ST-G has a new Ti-LFS face that’s lighter, stronger and faster. Tour test sessions with Mizuno players have highlighted an average 1.5mph ball speed gain by switching to the material over the previous SAT2041 face.  

A new carbon fiber wrap-over crown eliminates inefficient mass from the toe, helping also to absorb vibration and tune sound/feel to desired levels.   

Tour tested        

To get drivers in play on tour Mizuno start with their tour team, developing the look, sound and feel of new drivers. Then their R&D boffins build in whatever game enhancing tech the company has come up with.

The ST-G has been designed with additional internal sound ribs to create the sound and feel favoured by their tour staff. And no matter what weight configuration you choose golfers get the same impact feel, sound and feedback, which isn’t the case with all adjustable drivers on the market.

Video: How does the Mizuno ST-G 440 compare to other drivers?

Verdict: Mizuno ST-G 440 driver

Mizuno drivers are seeing a slight uptick on tour thanks to changes in the equipment contract landscape, and the 440cc ST-G is their latest ultra-low spin model. Mizuno says the model can be everything from a compact back-weighted stability driver to a low-spin bomber, but from our test experience, I’d recommend being very careful if you find yourself drawn to this model.

The G is only available at a 9.5° loft which immediately says to me the model is not for everyone, as so few club golfers need less than 10.5° loft on a driver to launch shots successfully into the air. Even dialed up to our 10.5° test loft and with both sliding weights positioned toward the back of the head our test pro struggled to launch the model in the same way he did for our other low-spin drivers. A phenomenon totally supported by our test data.

Posting a ball speed of 162 mph means this driver is fast, but from there, launch and spin are low which led to a low peak height and shots flying on a low bullet-like boring trajectory, which just isn’t easy to live with on the golf course.      

I’d suggest you need significant levels of speed to even consider looking at the ST-G in 2024 and even then I’d urge you to try the brand’s X model at the same time, it’s more forgiving and already has a couple of tour wins under its belt.

Data comparison: How does the Mizuno ST-G 440 compare to other leading drivers?

To see how the ST-G performs we put it up against the leading 2024 low-spin driver models in the hands of TG Test Pro Neil Wain at Keele Golf Centre. Our test data below shows how all the models compare.

Driver	Ball Speed	Launch Angle	Backspin	Height	Descent Angle	Carry Distance	Shot Area
Titleist TSR4 (10° – Tensei Blue)	162.4 MPH	10.8°	1921 RPM	28 YDS	32.8°	277 YDS (1)	589 SQ YDS
Callaway Paradym Ai Smoke TD (Denali S – Back Weight)	161.9 MPH	11.2°	2099 RPM	31 YDS	36.2°	276 YDS (2)	424.5 SQ YDS
TaylorMade Qi10 LS (Tensei Blue S)	163.6 MPH	10.7°	2338 RPM	32 YDS	37.8°	275 YDS (T3)	1148.4 SQ YDS
Callaway Paradym Ai Smoke TD (Denali S – Front Weight)	161.7 MPH	10.2°	1896 RPM	25 YDS	31.5°	275 YDS (T3)	553.8 SQ YDS
TaylorMade Qi10 LS (Diamana X)	160.4 MPH	12.5°	2260 RPM	36 YDS	39.9°	274 YDS	179.2 SQ YDS(2)
Cobra Darkspeed LS (Lin-Q Blue)	159.9 MPH	11.8°	2007 RPM	31 YDS	35.7°	273 YDS	1089 SQ YDS
PXG 0311 GEN6 (Aldila NV Green)	161.1 MPH	10.5°	2240 RPM	30 YDS	36.9°	271 YDS	147.6 SQ YDS (1)
Titleist TSR3 (10° – Tensei Blue)	162 MPH	10.5°	2435 RPM	32 YDS	38.2°	271 YDS	566.8 SQ YDS
Ping G430 LST	161.4 MPH	9.7°	2301 RPM	28 YDS	35.1°	270 YDS	246.4 SQ YDS (3)
Callaway Paradym Ai Smoke TD (Ventus Blue – Back Weight)	161.7 MPH	9.9°	2006 RPM	26 YDS	32°	270 YDS	800.8 SQ YDS
Srixon ZX7 MK II	159.8 MPH	11.4°	2313 RPM	32 YDS	38.2°	269 YDS	1036.5 SQ YDS
Wilson DynaPWR Carbon	158.5 MPH	11.2°	1828 RPM	27 YDS	32.9°	269 YDS	509.6 SQ YDS
Mizuno ST-G 440 (9.5° – Back Weights)	162 MPH	9.1°	2109 RPM	24 YDS	31.3°	268 YDS	442 SQ YDS
AVERAGE	161.3 MPH	10.7°	2135 RPM	29.4 YDS	35.3°	272 YDS	595 SQ YDS

*All lofts at 10.5° unless otherwise stated.

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Mizuno ST-G 440 (2023) driver

RRP: £549

Lofts: 9.5°/ 10.5° (USA only)

High launch shaft options: EvenFlow Riptide CB, UST Helium

Mid-High launch shaft options: UST Lin-Q

Mid launch shaft options: Aldila Ascent, Fujikura Motore X F3, Mitsubishi Kai'Li Blue, Mitsubishi Tensei AV Raw Blue

Low launch shaft options: HZRDUS Smoke Black RDX, HZRDUS Smoke Green RDX

For further information visit the Mizuno website here