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A New Report Saying The Next-Gen Subaru STI Comes With 420HP Is Laughable

How much horsepower will the 2023 Subaru WRX STI have when it arrives next year? A new report says 420 horsepower. Find out why the information is false.

Subaru of America has not released any information on the next-generation 2023 Subaru WRX STI, but rumors about how much horsepower the new performance sedan will have are still coming. A new report from Forbes says the new STI will outperform the Mercedes-AMG 45 S and come with 420 horsepower.

The recent Forbes report says a "source close to Subaru" told them (Peter Lyon contributor) the 2023 Subaru WRX STI "modifications will elevate the STI's power to a figure hovering around 420 horsepower with maximum torque clearing 362 lb-ft."

2023 Subaru WRX STI, next-generation Subaru STI
photo credit: @arnold_design

The only accurate part of the report is that the next-generation WRX STI will come with a 2.4-liter turbocharged Boxer engine. He says the 2.4-liter will get a "larger turbine and intercooler, reinforce the engine's internals with bespoke pistons and (connecting rods), remap the ECU and fit a special exhaust system."

Here is why the report is inaccurate and just a fabricated rumor. First, Subaru Corporation couldn't care less about the German automaker. The Mercedes-AMG 45 S is not WRX STI's competition.

2023 Subaru WRX STI, next-generation Subaru STI
photo credit: Subaru Corporation

The current-generation 2021 Subaru WRX STI 2.5-liter turbocharged Boxer four-cylinder engine produces 310 horsepower and 290 lb-ft of torque. Subaru is only concerned about the Volkswagen Golf R and the Honda Civic Type-R compact sports cars, not the Mercedes-AMG 45 S luxury model. How do we know?

Take a look at what Subaru did with the new 2022 WRX. They kept the WRX horsepower above or close to the competition. The 2022 WRX has 271 horsepower, the Volkswagen Golf GTI is rated at 241 horsepower, Hyundai Elantra N produces 276 horsepower, and the Honda Civic Si now has 200 horsepower and 192 pound-feet of torque.

Subaru will do the same with the new STI and make sure it compares favorably or outperforms the Honda Civic Type-R and the Volkswagen Golf R's horsepower ratings. The two compact sports cars are STI's competition.

The 2022 Volkswagen Golf R's 2.0-liter inline-four-cylinder turbocharged engine produces 315 horsepower and 310 lb-ft of torque. The 2022 Honda Civic Type-R 2.0-liter inline-four cylinder engine makes 306 horsepower and 295 lb-ft of torque.

How much horsepower will the 2023 Subaru WRX STI have when it arrives?

The next-generation Subaru WRX STI will not have 420 horsepower and 362 lb-ft. of torque. The all-new 2.4-liter turbocharged Boxer engine will likely have 100 horsepower less and come in at around 320 horsepower and 295 lb-ft of torque to beat its primary competition.

What's next for the 2023 Subaru WRX STI?

The 2023 Subaru WRX STI will upgrade the new 2.4-liter FA24 turbocharged Boxer engine with additional power. The new STI will ride on the new Subaru Global Platform and get significant suspension and brake upgrades.

When can I buy the 2022 Subaru WRX STI?

Subaru should introduce the new STI next summer and begin producing the all-new 2023 WRX STI during the fall of 2022. The STI won't make its dealer launch until early 2023.

The recent report from Forbes says the new STI will outperform the Mercedes-AMG 45 S and come with 420 horsepower. It's all rumor and more false information for the next-generation 2023 Subaru WRX STI.

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Denis Flierl has invested over 30 years in the automotive industry in a consulting role working with every major car brand. He is an accredited member of the Rocky Mountain Automotive Press. Check out Subaru Report where he covers all of the Japanese automaker's models. More stories can be found on the Torque News Subaru page. Follow Denis on Facebook, Twitter, and Instagram.

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Photo credit: main image @arnold_design


Silas Jordan (not verified)    January 7, 2022 - 6:33PM

In reply to by CharlesE (not verified)

There might be hope in this. The new BRZ is rated at 228hp, but many are measuring real close to that at the wheels at 215-220whp. And a lot of late model STi's are the same. the 18+ seem to regularly dyno at about 270-275whp stock. Assuming 20% drive train loss thats around 340 crank.

Zach (not verified)    December 30, 2021 - 10:16PM

In reply to by Lynk (not verified)

I’m a little confused at your comment, the article already mentions Mercedes doing it with a 4 cylinder, so it’s clearly possible, konnegsegg does it with a 3 cylinder that makes 600hp, so it’s clearly possible. I do suspect this article to be correct though, the sti will probably make 320-350 hp and see a substantial uplift in fuel economy from the current model, sky will be the limit for the aftermarket though

Jason (not verified)    January 14, 2022 - 11:26AM

In reply to by Wrawrx08 (not verified)

My comment about a V6 boxer engine was obviously sarcasm because, by definition, such a thing can't exist. A boxer engine has a cylinder angle of 180°, while a V engine is anything greater than 0° and less than 180°.

Ejbuilder (not verified)    March 6, 2022 - 1:08PM

In reply to by Matthew J Edwards (not verified)

A V 6 means 6 cylinders in a V shape.
Subaru uses H6 or Flat 6 boxer engines which are not in a V shape.
Just like an I6 is not a V6, neither is an H6.

Do you get it now?

What? (not verified)    December 30, 2021 - 8:13PM

For one, the Forbes article is already saying it's an article by saying "source close to Subaru". Anyone with common sense that read it would already know it's a rumor. For two, the Forbes article doesn't say anything about Subaru caring about topping Mercedes' performance. They use the AMG as a valid comparison, that is it. Dial down the sensationalism, lol.

Dane Carpenter (not verified)    December 30, 2021 - 10:56PM

I could believe the Torque numbers but not the HP numbers. It's been easy to get those torque numbers to the wheels relatively easily with the EJ25. I would assume the same with the FA25. And Subaru turbo charged boxer motor normally makes more torque than HP

Danny van Delft (not verified)    December 31, 2021 - 3:01AM

You retards have been spouting that the new STI will have 400 hp for YEARS, and now you think it's laughable?? Only thing laughable is this site's credibility.

RealTruth (not verified)    December 31, 2021 - 12:38PM

The part I love the most about this is the irony of the guy who makes up half his content, calling out someone else for *potentially* making up stuff.

I wonder how many people were disappointed when the FozXT/Foz Wilderness turbo never happened after you told them it would.

Eric (not verified)    December 31, 2021 - 1:57PM

So Forbes has a source for its reporting but you're able to refute it based on your gut feeling? Lmao.

You might be right but you're just guessing.

Martin (not verified)    January 1, 2022 - 4:55PM

I'm not sure why would anyone think 400hp is overstated. Mercedes makes more power with smaller engine. Slightly bigger turbo with VGT will easily kick 400+ HP even at the wheels if asked. Even if STI isn't a competitor to AMG, there is no reason to believe it won't come juiced up. STI has been using the same engine architecture for over a decade. Now that wrx closed the power gap, it's logical that STI leaves the boys club and advances into man's one...

Mike-L (not verified)    January 1, 2022 - 11:51PM

It’s very clear they aren’t shooting for Mercedes. If they were it would have a proper twin clutch gearbox, instead of the antiquated manual. Since Subaru has no twin clutch, or even a good geared automatic, they aren’t playing with Mercedes or the A45.

Jason (not verified)    January 6, 2022 - 2:02PM

In reply to by Mike-L (not verified)

I'm very thankful that Subaru doesn't have a good automatic and that they keep making the manual transmission for these cars. I don't care what's faster for bragging rights, just what I have more fun driving. If somebody wants an auto, then there's already plenty of choices, no need to add to that list.

Lee Schwartz (not verified)    January 6, 2022 - 1:46PM

i think the main thing for me would be the twin scroll turbo system that i like so much in my 2015 wrx. it literally leaps off the line. i have never been beaten off the line like that by any ford gt. they are usually shocked. sti model presently has too much turbo lag. will the new sti leap off the line or continue with turbo lag. i dont care nearly as much about horsepower as i do about being like the wrx.

Carl (not verified)    January 8, 2022 - 5:41PM

Subaru could make this with 450Hp if they wanted to but it all comes down to COST and the warranty. Most drivers cannot handle 350Hp let alone 450Hp.

Sam (not verified)    January 14, 2022 - 2:38PM

If this is true, Subaru has clearly forgotten what made the STI great.

I know that HP is not what makes a car great but it certainly matters and attracts buyers so...

Back in 2004 the STI had ~300 HP. Guess what? The mustang GT at the time had around 300 as well, and mustangs back then couldn't take a corner. The charger didn't exist, and the Camaro was still an f-body that couldn't handle for shit and had low 300's HP-wise. The E46 M3 had 330-something, pretty sure the RS4 wasn't sold in the states and the S4 had 250 HP, not sure if the C class had anything above the C32 AMG which was in the low/mid 200's.

No, these cars are not in the same class but somebody would be a fool to think that the STI's popularity and greatness wasn't large in part contributed to by comparing it to these cars. For 30k you could get something with similar power to a something german and fast, or a V8 muscle car, but something that could also stop and handle, and worked in ice and light snow. It cost much less than the german sports sedans of the time.

Now the STI has ~300HP, 0-60 in the low 5's, 1/4 mi. is low 13's... I'm sorry, I want an STI that has been able to catch up to the muscle cars and german sports sedans, otherwise it's absurd paying well over 40k for a 300hp Subaru. I know it's "not about power" but by not keeping up, it's losing its original appeal. This thing needs to run 0-60 in the very low 4's and a 1/4 mi. in the low 12's.

The only plus I can think of is if the powertrain is built to withstand tuning the car to at least that level performance with a couple bolt-ons, no crazy expensive upgraded DI injectors and high pressure fuel pump, and a re-flash while still remaining very reliable and a mod-friendly dealer network. This won't happen.

Carl (not verified)    January 15, 2022 - 1:00AM

In reply to by Sam (not verified)

I will be surprised if the new STi doesn't crack 350Hp for our market. We are also spoilt with JDM cars we can import as we are also right hand drive. If you want a 6 speed manual and AWD then there is no other choice, Subaru owns this market now.

Carl (not verified)    January 15, 2022 - 1:06AM

In reply to by Sam (not verified)

Chances are the engine will be both Direct Injection and Port Injection. We can retune over here for 98 Octane fuel, run more boost and the car will hit 400Hp anyway. I'm hoping I don't need to fiddle with the tune at all and it rolls out of the factory with 400Hp.

Silas Jordan (not verified)    January 15, 2022 - 9:58AM

In reply to by Carl (not verified)

Hopefully it will be port and direct, like the BRZ, but I read that the BRZ has that because it's Toyota tech and they co-developed it with them with their GR86. And they can't put it on other normal subarus. They could have with the 2015 wrx revision, they could have with the 2022 wrx revision, but they haven't.

I hope I'm wrong, because it's solid on the BRZ, also keeps the valves clean, but I'm not holding my breath just yet.