Skip to main content

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.

You Might Also Like: The Next-Gen Subaru STI Is Next To Get Those Controversial WRX Plastic Fender Flares

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.

Subaru Report - We’ve got you covered! Check back tomorrow for more unique, informative SUBARU news, reviews, and previews you can trust.

Leave your comments below, share the article with friends and tweet it out to your followers!

Photo credit: main image @arnold_design


Chris (not verified)    January 17, 2022 - 6:07PM

This article didn't do it's research. Subaru is Benchmarking a Mercedes AMG meaning they DO care about it's performance and are looking to beat it. Should do some research prior to making this article

Carl (not verified)    January 18, 2022 - 3:57PM

In reply to by Chris (not verified)

The problem is not that Subaru can beat the Mercedes power its COST. The AMG A45S is $112K and the outgoing STi is $65K for comparison over here so the Merc is almost TWICE the cost. The available market will shrink pretty quickly if the new Subaru comes out over here at say $80K plus. I'm picking the new STi will have to be in the $70-75K area. The real question is how much would you pay for a 420Hp Subaru STi out of the factory ?

Carl (not verified)    January 26, 2022 - 4:43AM

More information has come to light. The New WRX makes the same power as the old model BUT with 4 PSI less boost. 12 PSI not 16 PSI, big difference thats worth 40Hp so even if the new STi is "only" 350Hp, an aftermarket ECU tune for 98 only fuel and an increase in boost will get it to 400Hp. If its 400Hp out of the factory then 420Hp will be easy.

NMK (not verified)    January 26, 2022 - 6:39PM

IDK about 420, but i think 320 is an under statement. The new WRX makes 271HP but that is on regular 87 octane and only 12lbs of boost which is actually less than what is already found in the subaru ascent and outback with the same engine. That is why the wrx makes more HP and less TQ. It makes less peak boost but holds it all the way to redline. That car with a simple tune and 93 octane will make 320HP easily with zero other mods. If subaru makes upgrades to the turbo, intercooler and a few other odds n ends I see no reason we cant get 350 out of it in stock form.

Carl (not verified)    January 27, 2022 - 1:10AM

In reply to by NMK (not verified)

Exactly right it makes 271Hp with 4 psi less boost than the old model on 87 gas. We have 98 gas over here so a tune and more boost and it will be making the same as the outgoing STi. The new STi will have an engine with different internals, probably both port and direct injection and a better turbo. Expect the same sort of gains with a tune and 98. If it doesn't make 400Hp out of the factory its not going to take much to get it there.

David (not verified)    February 3, 2022 - 1:41PM

It's really not hard to tap into power on the FA motors. The factory just under builds them. Tuners are hitting 400hp in the FA20 pretty easily, but they have to replace the rods and Pistons because they're MIM parts once you get past that point you get failures. With fully built short blocks the limiting factor after that is you max out the high pressure injectors. Assuming the the FA24 is not all that different, which it really isn't, you can pretty easily get to 420.

Carl (not verified)    February 3, 2022 - 3:59PM

In reply to by David (not verified)

You mean the Subaru factory effectively de-tunes them. This is good, I would rather pay a couple of thousand extra to get the right parts in the engine to start with so you can add another 50Hp by simply re-mapping the ECU and running a higher octane fuel and increase the boost. As I said before if the STi comes out "Built to handle 400Hp" you can take it there easily if it comes out of the factory with 350Hp.

Joe (not verified)    March 6, 2022 - 8:35AM

"The next gen STI will NOT come with 420 hp..." lol love that. How do YOU know that?
Anyways you're forgetting the RS, I'm sure Subaru doesn't want to be embarrassed by Ford again going forward. Bigger turbo and remapped ECU should land the next gen around 350 I would think! 320 nowadays is almost pathetic. The Stinger is pulling 10% more than that now! And that's a KIA!