2.5 vs. 2.0

[tallguylehigh]

I have kind of been thinking about this for a while now and I was curious to know if anyone else here was thinking the same thing. If it has been discussed already I apologize.

 

It pertains to the engine in our cars, most notable the 2.5L turbo. Now when this engine was initially released, most were excited because it provided good torque numbers. But now I am wondering if SOA made the right decision with giving us the 2.5 instead of the 2.0. The 2.0 is used in Japan and has been placed on many top engine lists. Not to mention that the Subaru engineers are in Japan, and thusly, and upgrades to be consistently given would be to their top of the line engine, the 2.0T.

 

So although our engine is larger out of the box... with the continuous advancement of the 2.0T, does anyone wish Subaru would maybe downsize (heresy in the market I am sure) the engine size to give us thie superior 2.0 engine instead of our 2.5?

 

Let me know how you feel with your votes and comments,

 

Thanks!

[wukindada]

The 2.5 will get there, give it another year or so;)

Displacement is always a good thing!!

[700watts]

Say it with me now

“THERE’S NO REPLACEMENT FOR DISPLACEMENT!!!”

“THERE’S NO REPLACEMENT FOR DISPLACEMENT!!!”

“THERE’S NO REPLACEMENT FOR DISPLACEMENT!!!”

:D :D :D :D :D :D :D :D :D :D

 

Repeat as many times as necessary

[LIZARD]

Say it with me now

“THERE’S NO REPLACEMENT FOR DISPLACEMENT!!!”

“THERE’S NO REPLACEMENT FOR DISPLACEMENT!!!”

“THERE’S NO REPLACEMENT FOR DISPLACEMENT!!!”

:D :D :D :D :D :D :D :D :D

 

Repeat as many times as necessary

 

+100!! Just as there is NO substitue for MORE cylinders!!!

[rony]

Say it with me now

“THERE’S NO REPLACEMENT FOR DISPLACEMENT!!!”

“THERE’S NO REPLACEMENT FOR DISPLACEMENT!!!”

“THERE’S NO REPLACEMENT FOR DISPLACEMENT!!!”

 

Repeat as many times as necessary

 

+10

[andrew.anderson]

I voted for the 2.5T also. I am still holding out for the 3.0T from SOA though. I know PDXTuning and Perrin and working on one. One with a Subaru Factory Warranty would be nice though.

[Vimy101]

I'm in favour of using fewer resources to get the job done. When the OEMs went to 3.5 liter 6s, that's when I started looking for 4 bangers. Don't get me wrong though because I love power and torque and do realize that there is no replacement for displacement. However, I read something a while back that said something to the effect that a car will never use the amount of energy in gasoline to power it than the energy that was used for its manufacture. If people really want to help out with CO2 emmisions and energy conservation, they should drive smaller. Not only are they easier on fuel but they are also easier on mother earth as a whole.

 

(No, I'm not a hippy. I just find elegance in efficient solutions.)

[Beanboy]

What tech features does the 2.0 have the 2.5 doesn't? Differences are bolt-on related, not block-related.

 

Drove a WRX, the on/off nature was not acceptable to me. When the 2.5L appeared, put a big smile on my face and bought a Subaru with it.

[john_knoxville]

didn't the 2.5 Turbo win the International Engine of the Year Award for its engine class, which included 2.0 liter engines? why would you think the 2.0 is better?

[700watts]

However, I read something a while back that said something to the effect that a car will never use the amount of energy in gasoline to power it than the energy that was used for its manufacture.

 

I'm to sure about that one.....Over the life time of a vehical and the amount of energy stored in gas....hmmmmm...that just dosn't sound correct. Now I know car car dosn't use all the energy in gas all that effeciantly. But..that still dosn't change much.

[tintinet]

Had the 2.0 WRX. Nice engine, but the 2.5 torque blows it away.

[Th3Franz]

Give the 2.5L a properly sized twin scroll turbo out of the box and see what happens.

[jagcars26]

This is kinda like comparing old Chevy smallblocks 327 versus 350,,both excellent,but bigger is better usually.

[captainmorgan]

The 2.5L is also a semi closed deck as opposed to the 2.0L being an open deck.

[rallispec]

never driven the 2.0l subaru's... but i cant see anyway that it would be better than the 2.5.

[Vimy101]

I'm to sure about that one.....Over the life time of a vehical and the amount of energy stored in gas....hmmmmm...that just dosn't sound correct. Now I know car car dosn't use all the energy in gas all that effeciantly. But..that still dosn't change much.

 

I wish I could get my hands on that article so I could go over their numbers again. However, they figured in all the energy inputs used to manufacture a car from mining iron ore to the energy locked in the plastics, etc.

[TDC Joe]

5.0L 4cyl FTW!!!!

[TSiWRX]

2.5T all the way.

 

[Kostamojen]

Who the heck would want the 2.0T after having the 2.5T???

 

The only thing "better" about the JDM 2.0T's are the twin scrolls as mentioned. Dont really need the win scroll with the 2.5, but I would like to see a S204 VF42 on a EJ257 That should be interesting.

 

Personally, I think we got the 2.5T because the 2.0T just was aweful in automatic form, and they didnt want to put that in the Foresters or Legacys which mostly sell as automatics.

[700watts]

I wish I could get my hands on that article so I could go over their numbers again. However, they figured in all the energy inputs used to manufacture a car from mining iron ore to the energy locked in the plastics, etc.

 

Well here’s how I thought about it….. We all know the cost of energy; I thought roughly over the life of the vehicle we pay more in fueling the vehicle than we do on the vehicle. I know that’s a really rough way at looking at things, but we know this. Nothing on this earth is free and energy can’t be created or destroyed just changed. Therefore the cost of fuel should be a relatively easy way to figure that out. Given all things being equal. In other words if it takes so much energy to create a car than I believe the cost would be a lot higher. I could be dead wrong but I don't think I'm too far off...

[tallguylehigh]

didn't the 2.5 Turbo win the International Engine of the Year Award for its engine class, which included 2.0 liter engines? why would you think the 2.0 is better?

 

I was only saying that the 2.0 may be refined and updated moreso than the 2.5 because it is closer to the engineers in Japan.

 

Give the 2.5L a properly sized twin scroll turbo out of the box and see what happens.

 

That is kind of the point, the 2.0, although being smaller, has more advanced components out of the box from Subaru, resulting in higher numbers. Now granted some of these power gains are due to the difference Japan vs. US gas, but why is the 2.5 lacking some of the high tech goodies of the 2.0?

[700watts]

I voted for the 2.5T also. I am still holding out for the 3.0T from SOA though. I know PDXTuning and Perrin and working on one. One with a Subaru Factory Warranty would be nice though.

 

 

You know I like the idea too....but I'm afraid the vehicle might plow around corners because of the added weight. Our vehicles already have an inkling to push now. But it might work….I certainly hope I’m wrong…..

[IwannaSportSedan]

US Emissions standards is the boilerplate answer I always hear.

 

I'd think a 3.6-3.7 liter H6 with good specific horsepower, or a light turbo'd H6 would be a better choice, marketing wise, than a twin-scroll 2.5 OEM from Subaru.

 

People already have preconcieved notions about highly stressed four cylinder turbo motors producing a lot of horsepower. Ticking time bomb...

 

I am not saying they are right, and in Subaru's case, that inference would probably be wrong. But people like more cylinders under less stress to make comparable power. Especially if they were to use anti-lag technologies, like a single or two-stage dual small turbos, a system like Prodrive's anti-lag system, Variable geometry, or twin scroll turbos, or rotrex's two-speed gear reduction superchargers, or even higher static compression and direct fuel injection with a turbo/supercharger. something to smooth out the torque curve of pressurized induction system. Maybe even TPH... where an electric drive motor adds torque in the lower rev range, to supplant the turbo's added power.

 

If Subaru were to market a 320-370hp version of any of it's cars, I am not sure how the buying public would handle a four-cylinder making that figure, where a 6-cyl making that kind of power isn't such a stretch to imagine.

 

But I agree, there isn't really any inherent benefit of a 2.0 over a 2.5. WRC Homologation rules are probably all that are keeping Subaru tied to the 2.0 liter format. If WRC would open up to 2.5 or 3.0 liters, I would think that a lot of the JDM market cars would be getting the 2.5t that are getting the 2.0t now, namely WRX/STI and Legacy. That would also spread to other asian and euro markets, since all those cars are built in Japan.

 

Consolidated engine manufacturing is a legitimate cost benefit, and one reason USDM has gone away from the 2.0 to the 2.5 across the US market lineup, including the Impreza, WRX, and Forester.

[tallguylehigh]

US Emissions standards is the boilerplate answer I always hear.

 

I'd think a 3.6-3.7 liter H6 with good specific horsepower, or a light turbo'd H6 would be a better choice, marketing wise, than a twin-scroll 2.5 OEM from Subaru.

 

People already have preconcieved notions about highly stressed four cylinder turbo motors producing a lot of horsepower. Ticking time bomb...

 

I am not saying they are right, and in Subaru's case, that inference would probably be wrong. But people like more cylinders under less stress to make comparable power. Especially if they were to use anti-lag technologies, like a single or two-stage dual small turbos, a system like Prodrive's anti-lag system, Variable geometry, or twin scroll turbos, or rotrex's two-speed gear reduction superchargers, or even higher static compression and direct fuel injection with a turbo/supercharger. something to smooth out the torque curve of pressurized induction system. Maybe even TPH... where an electric drive motor adds torque in the lower rev range, to supplant the turbo's added power.

 

If Subaru were to market a 320-370hp version of any of it's cars, I am not sure how the buying public would handle a four-cylinder making that figure, where a 6-cyl making that kind of power isn't such a stretch to imagine.

 

But I agree, there isn't really any inherent benefit of a 2.0 over a 2.5. WRC Homologation rules are probably all that are keeping Subaru tied to the 2.0 liter format. If WRC would open up to 2.5 or 3.0 liters, I would think that a lot of the JDM market cars would be getting the 2.5t that are getting the 2.0t now, namely WRX/STI and Legacy. That would also spread to other asian and euro markets, since all those cars are built in Japan.

 

Consolidated engine manufacturing is a legitimate cost benefit, and one reason USDM has gone away from the 2.0 to the 2.5 across the US market lineup, including the Impreza, WRX, and Forester.

 

Great post and I totally agree... there is a preconceived notion that FI engines with high horsepower per displacement are overly stressed and therefore unreliable. If Subaru wants to start looking at horsepower numbers north of 320, they may have to start looking at a flat 6.

 

As for the 2.5 engine, it has absolutely worked wonders for Subaru in America. Between the STi, Legacy and Forrester, all of these cars have gotten a much needed performance boost because of this excellent engine.

[itsme]

This is kinda like comparing old Chevy smallblocks 327 versus 350,,both excellent,but bigger is better usually.

Not true. I have a 327 from a '68 vette in my '56 ford F-100. And if you check the books 327 always made more power then the 350. If I remember correctly the 327 fuelie made 375hp and the highest rated 350 made I think 350hp.