S650 GT vs. S550 GT Impressions & Comparisons

[MidwayJ]

I've now owned my 2026 Mustang GT A10 premium performance pack for a little less than 2 months. It's my 3rd Mustang. I previously owned a '19 GT premium for about 5.5 years. Prior to that I had a '15 V6. I thought I'd provide some early impressions of the car in comparison to my '19. Keep in mind I'm barely past the break-in period and haven't had the chance to do any spirited driving.

The A10 transmission is clearly better in the '26. Unlike many S550 owners I was satisfied with the 10-speed on my '19. It was a little sluggish in normal mode (I always figured it was largely due to the 3.15 rear end ratio), but it performed well in sport mode. Nonetheless, the A10 in this car is more responsive and eager to downshift while also being smoother. Bravo to Ford for improving it!

The car feels more responsive at part throttle in low RPMs than my '19, especially in normal mode. I suspect this is mostly because the '19 had a 3.15 rear end ratio while my '26 PP car has 3.55. Not sure if I'd notice a difference if it was an apples to apples comparison between two PP cars.

The steering feels a little quicker. I recall reading that Ford changed the steering a bit in this regard, and I can feel a difference. It makes the car feel a little more nimble and lighter in the front end. (With certain drivers, it might make the car more prone to going sideways pulling out of cars & coffee.) Although the steering feels quicker, it doesn't seem to be any better in terms of "feel of the road" at least in normal driving.

The steering is lighter effort in the S650. Sport mode in the new car feels like normal mode felt in the '19. Normal mode feels like comfort mode felt in the '19. I preferred normal mode in the '19 but now I prefer sport in this car. This is the opposite of going from my '15 V6 to the '19 GT. The steering feel was higher effort in the '19 compared to the '15.

I like the magneride. What's especially impressive is the ride in Sport mode feels softer than the modified suspension in my S550 (Bilstein dampers, BMR performance springs), while also feeling just as well controlled, if not better. Track mode rides stiffer than my S550, but I haven't done the type of driving needed to assess the handling in sport or track mode yet.

Normal mode is a bit disappointing. It feels a little softer than sport over minor bumps and rough spots but the car can feel less controlled and more unsettled over more significant bumps.

The stock active exhaust has a deeper tone but less "growl" than the Roush axle back I had on my S550. From the outside at idle I think I prefer the '26, but the Roush was much more fun from inside the car when giving it some throttle. With the stock resonator in place it was rowdy without being too raspy. The S650 sounds more muffled even in track mode. However, the new active exhaust sounds better than the stock, non active exhaust on my '19. It was boring and even more muffled from inside the car.

The car is a little quieter inside than my '19. There seems to be a little less road and wind noise. Not a huge difference but noticeable. It's just as loud over really gnarly pavement, but that varied by tire choice in my previous car.

I'm not sure about the 401A Package. Main reason I got it was because the one big screen no longer comes standard with the Premium 400A. The interior and seats don't look like a much of a step up from my S550 400A package. I knew a guy who had an S550 401A, and my memory might be wrong but I thought his seats looked nicer from a materials standpoint.

Compared to my S550 the seats feel firmer with better lumbar support. I like that, but on the long trip home from Iowa after picking up the car I noticed they were a little too firm for my bony hind end.

Dash/Screens are definitely not a deal killer. I still dislike how generic and "not like a Mustang" the screen looks from outside the car, but once I'm behind the wheel and the screens are lit up I don't much care. I like the gauge cluster screen a lot. Very readable with the info you want.

I'm still trying to get used to the center screen. For example, wireless Android auto automatically engages when I start the car. But then what if I want to quickly choose a different channel on the radio....

The gas mileage is worse than my S550. But I don't care. I suspect this is mostly due to being in the break-in period and the 3.55 gears vs. 3.15 in the '19. All good. I like the feel of the 3.55 much better. The gas mileage of my '19 was always a pleasant surprise to me, anyway.

The color of the new one is much better.

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[porterhousestk]

New car looks fantastic! I think this is a very fair review of the 650 in comparison, especially since you had two different versions of the 550. (I'm looking forward to upgrading/trading my Ecoboost for a GT soon!)

 

[LouG]

I've now owned my 2026 Mustang GT A10 premium performance pack for a little less than 2 months. It's my 3rd Mustang. I previously owned a '19 GT premium for about 5.5 years. Prior to that I had a '15 V6. I thought I'd provide some early impressions of the car in comparison to my '19. Keep in mind I'm barely past the break-in period and haven't had the chance to do any spirited driving.

The A10 transmission is clearly better in the '26. Unlike many S550 owners I was satisfied with the 10-speed on my '19. It was a little sluggish in normal mode (I always figured it was largely due to the 3.15 rear end ratio), but it performed well in sport mode. Nonetheless, the A10 in this car is more responsive and eager to downshift while also being smoother. Bravo to Ford for improving it!

The car feels more responsive at part throttle in low RPMs than my '19, especially in normal mode. I suspect this is mostly because the '19 had a 3.15 rear end ratio while my '26 PP car has 3.55. Not sure if I'd notice a difference if it was an apples to apples comparison between two PP cars.

The steering feels a little quicker. I recall reading that Ford changed the steering a bit in this regard, and I can feel a difference. It makes the car feel a little more nimble and lighter in the front end. (With certain drivers, it might make the car more prone to going sideways pulling out of cars & coffee.) Although the steering feels quicker, it doesn't seem to be any better in terms of "feel of the road" at least in normal driving.

The steering is lighter effort in the S650. Sport mode in the new car feels like normal mode felt in the '19. Normal mode feels like comfort mode felt in the '19. I preferred normal mode in the '19 but now I prefer sport in this car. This is the opposite of going from my '15 V6 to the '19 GT. The steering feel was higher effort in the '19 compared to the '15.

I like the magneride. What's especially impressive is the ride in Sport mode feels softer than the modified suspension in my S550 (Bilstein dampers, BMR performance springs), while also feeling just as well controlled, if not better. Track mode rides stiffer than my S550, but I haven't done the type of driving needed to assess the handling in sport or track mode yet.

Normal mode is a bit disappointing. It feels a little softer than sport over minor bumps and rough spots but the car can feel less controlled and more unsettled over more significant bumps.

The stock active exhaust has a deeper tone but less "growl" than the Roush axle back I had on my S550. From the outside at idle I think I prefer the '26, but the Roush was much more fun from inside the car when giving it some throttle. With the stock resonator in place it was rowdy without being too raspy. The S650 sounds more muffled even in track mode. However, the new active exhaust sounds better than the stock, non active exhaust on my '19. It was boring and even more muffled from inside the car.

The car is a little quieter inside than my '19. There seems to be a little less road and wind noise. Not a huge difference but noticeable. It's just as loud over really gnarly pavement, but that varied by tire choice in my previous car.

I'm not sure about the 401A Package. Main reason I got it was because the one big screen no longer comes standard with the Premium 400A. The interior and seats don't look like a much of a step up from my S550 400A package. I knew a guy who had an S550 401A, and my memory might be wrong but I thought his seats looked nicer from a materials standpoint.

Compared to my S550 the seats feel firmer with better lumbar support. I like that, but on the long trip home from Iowa after picking up the car I noticed they were a little too firm for my bony hind end.

Dash/Screens are definitely not a deal killer. I still dislike how generic and "not like a Mustang" the screen looks from outside the car, but once I'm behind the wheel and the screens are lit up I don't much care. I like the gauge cluster screen a lot. Very readable with the info you want.

I'm still trying to get used to the center screen. For example, wireless Android auto automatically engages when I start the car. But then what if I want to quickly choose a different channel on the radio....

The gas mileage is worse than my S550. But I don't care. I suspect this is mostly due to being in the break-in period and the 3.55 gears vs. 3.15 in the '19. All good. I like the feel of the 3.55 much better. The gas mileage of my '19 was always a pleasant surprise to me, anyway.

The color of the new one is much better.

Great review. I can't compare the two models, but what you've said about the S650 mirrors my thoughts

 

[MidwayJ]

New car looks fantastic! I think this is a very fair review of the 650 in comparison, especially since you had two different versions of the 550. (I'm looking forward to upgrading/trading my Ecoboost for a GT soon!)

It would have been a more interesting comparison if the '19 GT had magneride and a 3.55 gear ratio. Even so, the transmission performance and quieter cabin are clear improvements. The quicker steering is noticeable, and I think I prefer it, but it's probably a matter of personal preference for most. I can't wait to get this car out on some curvy roads!

 

[JediMindTrix]

I had a similar upgrade path to my now S650, and I have the same thoughts and reservations. Congratulations btw!

 

[smurfslayer]

Watching for the lols and inevitable S650 hate from the S550 worshipers...

 

[BoostRabbitGT]

Excellent review! I think you hit it spot-on with how the handling feels in the S650 GT compared to the S550 GT. (Weirdly enough the S650 EcoBoost felt identical in steering effort in comparison to the S550 EcoBoost, so I don't know why they couldn't carry that over for the GT.)

 

[MidwayJ]

Watching for the lols and inevitable S650 hate from the S550 worshipers...

"But it still looks like a Camaro."

 

[MidwayJ]

Excellent review! I think you hit it spot-on with how the handling feels in the S650 GT compared to the S550 GT. (Weirdly enough the S650 EcoBoost felt identical in steering effort in comparison to the S550 EcoBoost, so I don't know why they couldn't carry that over for the GT.)

Thanks. I don't really view the higher vs lower steering effort as necessarily good or bad as long as it can be adjusted. It seems interesting that it changed with the 2018 S550 refresh and then went back the other way with the S650. And it's strange that there was no change to the Ecoboost.

 

[kurto93]

I've now owned my 2026 Mustang GT A10 premium performance pack for a little less than 2 months. It's my 3rd Mustang. I previously owned a '19 GT premium for about 5.5 years. Prior to that I had a '15 V6. I thought I'd provide some early impressions of the car in comparison to my '19. Keep in mind I'm barely past the break-in period and haven't had the chance to do any spirited driving.

The A10 transmission is clearly better in the '26. Unlike many S550 owners I was satisfied with the 10-speed on my '19. It was a little sluggish in normal mode (I always figured it was largely due to the 3.15 rear end ratio), but it performed well in sport mode. Nonetheless, the A10 in this car is more responsive and eager to downshift while also being smoother. Bravo to Ford for improving it!

The car feels more responsive at part throttle in low RPMs than my '19, especially in normal mode. I suspect this is mostly because the '19 had a 3.15 rear end ratio while my '26 PP car has 3.55. Not sure if I'd notice a difference if it was an apples to apples comparison between two PP cars.

The steering feels a little quicker. I recall reading that Ford changed the steering a bit in this regard, and I can feel a difference. It makes the car feel a little more nimble and lighter in the front end. (With certain drivers, it might make the car more prone to going sideways pulling out of cars & coffee.) Although the steering feels quicker, it doesn't seem to be any better in terms of "feel of the road" at least in normal driving.

The steering is lighter effort in the S650. Sport mode in the new car feels like normal mode felt in the '19. Normal mode feels like comfort mode felt in the '19. I preferred normal mode in the '19 but now I prefer sport in this car. This is the opposite of going from my '15 V6 to the '19 GT. The steering feel was higher effort in the '19 compared to the '15.

I like the magneride. What's especially impressive is the ride in Sport mode feels softer than the modified suspension in my S550 (Bilstein dampers, BMR performance springs), while also feeling just as well controlled, if not better. Track mode rides stiffer than my S550, but I haven't done the type of driving needed to assess the handling in sport or track mode yet.

Normal mode is a bit disappointing. It feels a little softer than sport over minor bumps and rough spots but the car can feel less controlled and more unsettled over more significant bumps.

The stock active exhaust has a deeper tone but less "growl" than the Roush axle back I had on my S550. From the outside at idle I think I prefer the '26, but the Roush was much more fun from inside the car when giving it some throttle. With the stock resonator in place it was rowdy without being too raspy. The S650 sounds more muffled even in track mode. However, the new active exhaust sounds better than the stock, non active exhaust on my '19. It was boring and even more muffled from inside the car.

The car is a little quieter inside than my '19. There seems to be a little less road and wind noise. Not a huge difference but noticeable. It's just as loud over really gnarly pavement, but that varied by tire choice in my previous car.

I'm not sure about the 401A Package. Main reason I got it was because the one big screen no longer comes standard with the Premium 400A. The interior and seats don't look like a much of a step up from my S550 400A package. I knew a guy who had an S550 401A, and my memory might be wrong but I thought his seats looked nicer from a materials standpoint.

Compared to my S550 the seats feel firmer with better lumbar support. I like that, but on the long trip home from Iowa after picking up the car I noticed they were a little too firm for my bony hind end.

Dash/Screens are definitely not a deal killer. I still dislike how generic and "not like a Mustang" the screen looks from outside the car, but once I'm behind the wheel and the screens are lit up I don't much care. I like the gauge cluster screen a lot. Very readable with the info you want.

I'm still trying to get used to the center screen. For example, wireless Android auto automatically engages when I start the car. But then what if I want to quickly choose a different channel on the radio....

The gas mileage is worse than my S550. But I don't care. I suspect this is mostly due to being in the break-in period and the 3.55 gears vs. 3.15 in the '19. All good. I like the feel of the 3.55 much better. The gas mileage of my '19 was always a pleasant surprise to me, anyway.

The color of the new one is much better.

Really good comparison, I had two different s550’s and I’ve now got a Dark horse. I still really love my dark horse but I actually prefer the s550 as a car.
For some reason my s550 just felt more aggressive and more exciting to drive. The Dark horse feels a bit like a ‘normal’ car to drive sometimes.

 

[DFB5.0]

I've now owned my 2026 Mustang GT A10 premium performance pack for a little less than 2 months. It's my 3rd Mustang. I previously owned a '19 GT premium for about 5.5 years. Prior to that I had a '15 V6. I thought I'd provide some early impressions of the car in comparison to my '19. Keep in mind I'm barely past the break-in period and haven't had the chance to do any spirited driving.

Excellent post and comparison. I went from a 2016 S550 GT manual to a 2024 S650 GT A10, which considering I skipped the 2018+ update, my old vs new is more pronounced. (All Australian spec Mustang GT's come with the Performance Pack and Premium trim grade, be that S550 or S650)

The A10 transmission is clearly better in the '26. Unlike many S550 owners I was satisfied with the 10-speed on my '19. It was a little sluggish in normal mode (I always figured it was largely due to the 3.15 rear end ratio), but it performed well in sport mode. Nonetheless, the A10 in this car is more responsive and eager to downshift while also being smoother. Bravo to Ford for improving it!

I drove a few A10 S550's and found the gearbox excellent when hammering the car, but it got lost in normal around town type driving. I agree with you in that the S650 calibration is much better in normal conditions. I also love the rev-matched downshifts and how quickly it shifts in sport/track/drag modes.

However, I just wish they would sharpen up the response time to paddle inputs, especially downshifts. So while the shift speed is fast, the response speed isn't. I have both 6- and 8-speed ZF automatics in the same stable and both are considerably better in that regard.

The steering feels a little quicker. I recall reading that Ford changed the steering a bit in this regard, and I can feel a difference. It makes the car feel a little more nimble and lighter in the front end. (With certain drivers, it might make the car more prone to going sideways pulling out of cars & coffee.) Although the steering feels quicker, it doesn't seem to be any better in terms of "feel of the road" at least in normal driving.

Agreed, the rack is quicker but still lacking in feel.

The steering is lighter effort in the S650. Sport mode in the new car feels like normal mode felt in the '19. Normal mode feels like comfort mode felt in the '19. I preferred normal mode in the '19 but now I prefer sport in this car. This is the opposite of going from my '15 V6 to the '19 GT. The steering feel was higher effort in the '19 compared to the '15.

I always drove the S550 with the steering in comfort, mainly because it made the car feel more agile. Same for S650. But then that's always been a preference of mine.

I like the magneride. What's especially impressive is the ride in Sport mode feels softer than the modified suspension in my S550 (Bilstein dampers, BMR performance springs), while also feeling just as well controlled, if not better. Track mode rides stiffer than my S550, but I haven't done the type of driving needed to assess the handling in sport or track mode yet.

Normal mode is a bit disappointing. It feels a little softer than sport over minor bumps and rough spots but the car can feel less controlled and more unsettled over more significant bumps.

What impresses me about Magneride is how it nails down the body movements in sport/track modes, in turn giving you more confidence on winding roads. I'd probably like to see a more pronounced difference between the softest setting and sport/track modes, primarily to improve the ride quality when you just want to cruise.

On my S550, even with the Performance Pack chassis, I never liked how much body float there was at higher speeds, it made the car feel disconnected, and teamed with the lack of steering feel, you never really knew what was happening underneath you. And yet the PP setup had a brittle low speed ride.

The stock active exhaust has a deeper tone but less "growl" than the Roush axle back I had on my S550. From the outside at idle I think I prefer the '26, but the Roush was much more fun from inside the car when giving it some throttle. With the stock resonator in place it was rowdy without being too raspy. The S650 sounds more muffled even in track mode. However, the new active exhaust sounds better than the stock, non active exhaust on my '19. It was boring and even more muffled from inside the car.

On the pre-2018 update S550's, Australian/Euro spec V8 Mustang's had even quieter exhaust spec than the US cars. I'm not a big modifier of cars, but it was just waaaay too tame and I was driving the car more aggressive to hear the sound of the car. In the end I put a Borla Touring cat-back on it and the car came alive. Mine had the Borla central resonator, which reduced the harshness and drone you get with resonator delete packages.

Compared to the standard Active Exhaust on the S650, I'd say my Borla-equipped S550 had balanced volume from front to back. The S650 is all rear muffler, to the point where I think it needs an X or H pipe to balance the tone.

Either way, the 5.0 V8 Mustang is all about induction note, the beauty of a naturally aspirated layout. I think some go too far with exhausts, simply because it can sometimes drown out that induction note.

Dash/Screens are definitely not a deal killer. I still dislike how generic and "not like a Mustang" the screen looks from outside the car, but once I'm behind the wheel and the screens are lit up I don't much care. I like the gauge cluster screen a lot. Very readable with the info you want.

I'm still trying to get used to the center screen. For example, wireless Android auto automatically engages when I start the car. But then what if I want to quickly choose a different channel on the radio....

I think I prefer the more evocative S550 interior, so it's taken a while to warm to the S650 screen-fest. As you say, it's by no means a dealer killer. I will say though, moving common functions to the touchscreen is not smart, primarily because it creates a distraction from the road. Climate control in particular.

The gas mileage is worse than my S550. But I don't care. I suspect this is mostly due to being in the break-in period and the 3.55 gears vs. 3.15 in the '19. All good. I like the feel of the 3.55 much better. The gas mileage of my '19 was always a pleasant surprise to me, anyway.

I wear it like a badge of honor!

21.6 L/100km = 10.9 MPG

The color of the new one is much better.

Atlas Blue was my second choice, the more I see it, the more I wonder if I made the right choice. Classic Ford Blue.

 

[MidwayJ]

For some reason my s550 just felt more aggressive and more exciting to drive. The Dark horse feels a bit like a ‘normal’ car to drive sometimes.

The quieter cabin makes my S650 seem a little more refined, but hopefully the upcoming resonator delete will add some excitement.

 

[kurto93]

The quieter cabin makes my S650 seem a little more refined, but hopefully the upcoming resonator delete will add some excitement.

I’m trying to find a Ford approved garage to get a H pipe fitted so I don’t mess with the warranty! But I’m struggling to find one 🥲

 

[MidwayJ]

However, I just wish they would sharpen up the response time to paddle inputs, especially downshifts. So while the shift speed is fast, the response speed isn't. I have both 6- and 8-speed ZF automatics in the same stable and both are considerably better in that regard.

I agree. The delay was quite annoying in my S550 and although I haven't used the paddles much in the new one, there doesn't seem to be much improvement.

On my S550, even with the Performance Pack chassis, I never liked how much body float there was at higher speeds, it made the car feel disconnected, and teamed with the lack of steering feel, you never really knew what was happening underneath you.

I never drove a stock performance pack S550, but the mods I did to the non PP car made a big difference in handling. In particular, the BMR cradle lockout kit helped with the "slop" in the rear. Even so, the lack of steering feel and the sheer weight of the car limited how good it could be.

I think some go too far with exhausts,

Some go way too far. I'm in an S550/S650 group in my area and have been around lots of them. Headers combined with the loudest catbacks are ear splitting loud.

I will say though, moving common functions to the touchscreen is not smart,

Totally agree.

I appreciate the great comments!

 

[Delco73]

I also just came out of a S550 and...have some thoughts. New car (4th Mustang) is a '25 GT 401a, 3.55, convertible 10A, 20", Brembo, non-PP, no active exhaust. Shadow Black.

I had a 2015 GT convertible 6A, with a 3.15 rear and 20" wheels. The 10R80 + 3.55 is a HUGE upgrade over that 6-speed slushbox. Like damn. What a difference in performance. No complaints whatsoever.

Hot-button item AS/S is pretty good, actually. It's pretty unobtrusive and works about as well as my Telluride or Civic. I'm not offended by it's existence. If you turn on Auto-Hold plus the AS/S, it's terrible.

Steering is roughly the same for me in both cars - numb as hell, but comfortable. You're spot-on about the effort comparison. Ford really just screwed the pooch on the steering on this car. My Civic has more precise, communicative steering. Maybe it's the big 20" wheels, who knows. EIther way it blows.

I'm gonna catch heat for this but I much prefer the '15 exhaust to the '25. Reason? volume. I'm not a a loud exhaust guy. I hate it but this is a tradeoff for the rest of the whole Mustang experience. I think the exhaust sounds good, but I'd be happy with a much quieter setup. In hindsight, should have tried to find one with the active exhaust but cest la vie.

I've actually come around on the screens. I think everything works pretty well, everything is laid out perfectly, the retro gauges are awesome. Would have been cool to see if they could do something a little more stylish and maybe tried harder to integrate into a cohesive design but it's fine in general. It's not like they tried hard with the 87-93s but nobody cares about that. I do wish Ford had tried harder to cover up or change the S550 bits inside. The door panels are almost identical. That's kinda ridiculous that they re-used 10-year-old door handles. And a $66k car with seat memory yet also manually-adjustable seat backs is insulting.

Overall it's a significant jump over my '15. SO much quicker and more responsive with the 3.55 and 10R80. Nicer materials inside. comfortable but firm seats. Quieter inside, louder outside. The thing is, I don't generally drive hard, it's just a cruiser for me. The '15 would settle down and chill out more than the '25. It was also a lot less fun to drive...

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