I just don't understand it. From the first time I saw it at the Detroit Autoshow in 2003 and found out it had a 2.5 I was heartbroken. I am a huge Subaru rally fan and the rally car has a 2.0 so that is what the STi should be. I also think that the different engine caused it to lose every one of the magazine comparisons. The suspension in the STi is set up like the 2.0 from Japan so the 2.5 hurt the handling. Sure, it is extremely fast and I would take one over an EVO any day but I wish they had stuck to the rally inspired idea instead of trying to be able to say that they had more horsepower than the EVO. What do you guys think?

2.5 = more reliable at the same power and more low end, im happy with it even if it dont meet rally specs

they only have to make the car run race to race with the 2.0 pushing 300hp they can replace anything they want pretty much after every run but they have to keep it under 2.0, on the road we need something that will run longer than that and everyone wants the same power.

Wow, a lot of misconceptions there grasshopper....

1. Subaru only put the 2.5 in the USDM STI to meet American demand for bigger engines with more power.
2. The 2.5 doesn't effect the handling, the weight difference in engines in negligeble and STI compensated in the car set up, they didn't just pull out an engine and drop one in without adjusting the car's set up to compensate.

2.5 roxxx

The JDM WRX EJ20 motors have almost the same power as our USDM STi EJ25 motors.

Subaru had to add emissions-control equipment to the EJ20 when they brought over the WRX in 2002, which is why the USDM WRX only has 227 hp (compared to the JDM "276" hp.) So, they knew that the USDM would demand that a higher-trim-level STi would need to have more power than a regular WRX (even though they don't in the JDM!) so the only other way to get more power and maintain emissions compliance was to increase displacement.

I guess I could see how a "rally purist" would want to have the same 2.0, but for all practical purposes...2.5 rocks man! I don't think you'd complain about it once you drive it. It's all good.

by the way, Freakray:

It's "affect", not "effect"
It's "negligible", not "negligeble"

I'm not sure about this, but did they really do a whole lot of "adjusting the car's set-up", going from a 2.0 JDM STI to 2.5 USDM STI?

You just contradicted yourself from what you just said above--that handling and weight differences are negligible, so why do a whole lot of "adjusting" if the differences are negligible, and what DID they exactly adjust, grasshopper?

The JDM WRX EJ20 motors have almost the same power as our USDM STi EJ25 motors.

Subaru had to add emissions-control equipment to the EJ20 when they brought over the WRX in 2002, which is why the USDM WRX only has 227 hp (compared to the JDM "276" hp.) So, they knew that the USDM would demand that a higher-trim-level STi would need to have more power than a regular WRX (even though they don't in the JDM!) so the only other way to get more power and maintain emissions compliance was to increase displacement.

I hadn't heard that one but it sure makes a lot more sense than what I was told about it.

Durn right! This is America, dangit! America = displacement! Them lollipop Euro-brats and Asians are all about efficiency. This is America! Screw efficiency! Pure, hedonistic power is what this country is all about! 5.7 liters in a GTO! 12 cylinders in a Viper! We'll even make your little Japanese car better by giving it half a liter of dis-place-ment. That way, when you tune it to be emissions illegal and just get it inspected somewhere where you know a guy, it will be faster than the Jap version. God bless America! <salutes>

how much more does the 2.5 engine weigh? the sti still has better weight distribution than the evo though.

well 10 in a viper but whatever

who cares if a car is close to the rally spec. if you are rallying then buy a 2.0.

if you want to go faster get a 2.5.

If you like the 2.0 better, buy a WRX and put in the 6-speed w/ LSD and the STi suspension/brakes.

they couldnt get 300hp out of the 2.0 liter and still meet USA emission requirements, so they went with a 2.5liter engine so they could still achieve thier goal of 300hp.

And i doubt they could get a safe running 2.0liter 300hp engine with calis crappy 91 piss gas.

Have you gotten any recalls on your fabulous Mitsubishi?

they couldnt get 300hp out of the 2.0 liter and still meet USA emission requirements, so they went with a 2.5liter engine so they could still achieve thier goal of 300hp.

And i doubt they could get a safe running 2.0liter 300hp engine with calis crappy 91 piss gas.


They could easily but how much more would you be willing spend? 2.5l makes it easier to achieve higher hp cheaper.

They could easily but how much more would you be willing spend? 2.5l makes it easier to achieve higher hp cheaper.

Its actually...NOT THAT EASY, considering getting an ECU reflash for an EVO will put the evo to about 300-320 crank HP...the reflash will hold the 19-20psi boost till red-line....but youll have to be running 93octane...if you use that shitty 91, your gonna get some knock....so no 300hp isnt easily done with that watered down shit CALI gas.


nope, havent had any recalls.

I'm buying a RS2.5 with the intention of building on it (since I cant afford a WRX, and I prefer the GC8? body style)

excusing my ignorance,what would you need to do to have a wrx with the same hp than a japanese version?????

The only reason why they put the 2.5 in the USDM STi is because of emissions as well as power figures. The JDM STi still uses the 2.0 turbo engine for your information. The USDM STi boasts the high hp figures but in actuality the JDM 2.0 STi's were putting down well over 278 HP. The reason they stated it was 278 hp was because of the gentlmans agreement.

jay@af - you need to do a little more homework on the WRX's, in Japan they came out with 245hp compared to the 227 in the USDM one. In Japan the STi engine came out with 2 different engines... The STi wagons came out with 265hp while the STi sedans came out with 278 HP. Just my 4 cents

ninja_zx7r - basically you would need to remove all the 3 to 4 cats that you have in the USDM WRX so you could be able to have the power and more like the JDM WRX

ninja_zx7r - basically you would need to remove all the 3 to 4 cats that you have in the USDM WRX so you could be able to have the power and more like the JDM WRX

Well on that note; the JDM STi has 2 catalytic converters as well. And for all of you who think that the JDM STi makes ahmm... 280ps (276bhp)... well, thats what they "want" you to believe.

One thing which I will point out which rains supreme in my heart being the reason I own a MY00 STi is for that 7800 RPM rev limit. Also may be, its the fact that the GC8 is almost 300 lbs LIGHTER than the GD8 or GDB Impreza's!! Woow.

The only reason why they put the 2.5 in the USDM STi is because of emissions as well as power figures.

Emissions would be one reason. The power difference between the Japanese STI and the US-spec STI is negliable since the 276hp "rating" is only for advertising use...it's actually more than that in Japan. The PRIMARY reason would be for the 2.5L's improved torque curve, which is desired in the US.

Guu - Yes I understand that the JDM STi also has 2 cats but ninja_zx7r was asking How his WRX could be able to have the same hp rating as the Japan version... Im not saying STIs dont have cats... Which brings me to a good point... A WRX motor with 300 Hp and an STi motor with 300 Hp makes no difference except where the powerband starts and finishes...

Hudson - Thanks for that add... I forgot about that torque curve thing... Americans love torque... Japanese love High speed LOL... Strange isnt it???

Its actually...NOT THAT EASY, considering getting an ECU reflash for an EVO will put the evo to about 300-320 crank HP...the reflash will hold the 19-20psi boost till red-line....but youll have to be running 93octane...if you use that shitty 91, your gonna get some knock....so no 300hp isnt easily done with that watered down shit CALI gas.


nope, havent had any recalls.


funny i have 300 crank hp and it was easily achieved.

The Japanese may love high-speed, but they never get to use it. There's no such thing as "open road" in Japan. America and Australia and the UK have stretches of road where a car can just unload (not necessarily legally, but whatever). In my travels around Japan, there is NO such place there, except maybe on closed tracks. I would think the Japanese were more interested in fuel economy than top end, really. That's why drifting became popular in Japan; it's what their roads can support.

AMEN to that... Drifting the only sport that doesnt require reaction time LOL