6 Cyl. vs 2.5

[2000outback]

How do the two engines compare for reliabilty,performance..etc.What about the turbo version of the 2.5.I see the horsepower rating is similar but for everyday family use what would be the better engine?

[Manarius]

6cyl over Turbo engine for reliability. Less moving parts = less to break.

[subeman90]

in this case i will always vote for the reliablity of the H6 for the long haul but if i was going to lease a car and didn't care about upkeep in its later years i would go with the fun factor of the turbo 4cyl.

 

H6 doesn't have timing belts either which to me is a big +

 

either way you are going to be

[idosubaru]

they both appear solid. there aren't any significant issues to speak of for either one. the 2.5's have been around for over a decade now, there are lots of users, many active members and most people that work on engines here have seen them, taken them apart and played with them. many on here have yet to work on a 6 cylinder, take them apart and not many cumulative miles for the 6 cylinder members on this board. based on that, i'm conservative and would stick with the 2.5. only based on that it's *more* proven, not better. there are more samples, more time to verify the integrity and far more cumulative miles for the 2.5. that's all my own oppinion of course i don't think either motor is better than another...lest we start another argument out of this thread!

 

either way it appears you're getting a good motor.

 

the "6 cylinder" isn't unique. this is subaru's 3rd production 6 cylinder. in the late 80's early 90's was the ER27 and in the mid 90's was the EG33. both turned out to be excellent motors (although they cheated with the ER27 since it was basically an EA82 block with two more pistons literally slapped on).

 

but yeah - no timing belts is a huge ++ for sure.

not familiar with numbers but if power is a concern...definitely get the H6. much higher potentail than the 2.5 non-turbo.

[subeman90]

...and the 3.3 in the svx was a 2.2 with 2 more cyl put to it (so i have been told)

[Ranger83]

Advantages of H6 versus H4:

- More equipment standard.

- 5EAT trans

- lower final drive ratio

- Much more quiet, relaxed, powerful

 

Disadvantages

- 1-2 mpg less than 2.5 under most conditions

- more $$ than H4

- heavier than H4 models

- no tuning parts available currently

- 2007 only available in $$$ LLBean and VDC models

 

H4 turbo advantages

- Very fast - 15% more whp than the H6

- SI-Drive improves mileage

- Tons of engine parts available

- Can be purchased as 5mt or 5EAT in US.

- Can be purchased as Legacy GT (auto only) or Outback XT

 

H4 turbo disadvantage

- requires Premium fuel

- not as refined as H6 for long distance travel (but not horrible)

[Virrdog]

I have almost nil knowledge about the 6 cylinder engines, but the turbo 4 engines seem to typically be a notch above their naturally aspirated brothers. They get the latest technology and typically built much more robust like the closed deck 2.2T and now the semi-closed deck 2.5 turbo. And the turbo engines offer the absolute most flexibility when it comes to tuning it for more power down the road.

[Setright]

6 cylinder, everytime!

 

If only I could afford one myself

[2000outback]

My brother has a new Legacy with the 2.5 turbo and he loves it.I just wondered how they would stack up against the H6 for everyday family car use.I have noticed you don't read many posts on here about the H6.

[Ranger83]

My brother has a new Legacy with the 2.5 turbo and he loves it.I just wondered how they would stack up against the H6 for everyday family car use.I have noticed you don't read many posts on here about the H6.

 

Only old people buy them and they don't know how to use the internet....

[andrew_j]

6cyl over Turbo engine for reliability. Less moving parts = less to break.

 

If you get down to it there may actually be more moving parts in an h6 due to extra two pistons and extended valve train. Turbo cars only have a wastegate and a very simple turbo.

 

IMHO I agree h6 though will have a lower maintenance costs with timing chain. However I wonder if it will need to be pulled apart like the 2.5L when they spring inevitable oil leaks all over making the timing belt replacement possibily a mute point.

 

I am a turbo 2.5 owner with a 05 LGT 5MT wagon. The turbo motor simply trumps the H6 in power even though similar HP ratings. The H6 I drove for a day albiet auto was defintely smoother but the power curve not as great. I will say driving the LGT usually puts a smile on my face everyday. My wife the same.

[Ranger83]

If you get down to it there may actually be more moving parts in an h6 due to extra two pistons and extended valve train. Turbo cars only have a wastegate and a very simple turbo.

 

IMHO I agree h6 though will have a lower maintenance costs with timing chain. However I wonder if it will need to be pulled apart like the 2.5L when they spring inevitable oil leaks all over making the timing belt replacement possibily a mute point.

 

I am a turbo 2.5 owner with a 05 LGT 5MT wagon. The turbo motor simply trumps the H6 in power even though similar HP ratings. The H6 I drove for a day albiet auto was defintely smoother but the power curve not as great. I will say driving the LGT usually puts a smile on my face everyday. My wife the same.

The boy racers buy the turbo because it's quicker 0-60. In a magazine test the XT 5EAT was .2 seconds faster 45-65 than the H6 5EAT - that's about one car length. Burning regular fuel at a lower rate makes up for it. The H6 has been on the market since 2001 and it's an extremely durable, reiliable engine with a nearly flat torque curve.

 

Unfortunately Subaru does not offer the Spec B wagon in the US - Legacy wagon with 3.0R motor, 6 speed manual and Spec B suspension. 0-60 in 7 s for those who care. Go to the 22:10 minute mark of: http://video.google.com/videoplay?docid=-4486568282229035994&q=fifth+gear

for a track test.

[Virrdog]

The boy racers buy the turbo because it's quicker 0-60. In a magazine test the XT 5EAT was .2 seconds faster 45-65 than the H6 5EAT - that's about one car length. Burning regular fuel at a lower rate makes up for it. The H6 has been on the market since 2001 and it's an extremely durable, reiliable engine with a nearly flat torque curve.

And why are you anti-turbo...? Wanting more power does not make you a boy racer. Stock for stock they may be close in the slower speeds but that one car length will continue to grow if they keep going (and the turbo gets to spool for more than the 2 seconds it does in 0-60). It never ceases to amaze me how my turbo will keep pulling harder 75+. And the mod potential of the turbo is ridiculous. Subaru only keeps a cap on the non-STi turbo motors for PR reasons.

 

If you want a big fat smile on your face everytime you stab the throttle, get the turbo. If you want a compromise between sufficient power and gas mileage/grade, then a H6 would be your choice. When it comes to reliability, I would say its a toss-up. If kept stock, the XT motors are undertuned which leads to longevity (ask the 22t's ).

[andrew_j]

I have no idea of 0-60 in a LGT Wagon. Its my wife's car. I tried the Outback H6 for a day with her. The H6 felt weaker. The reason why is the H6 (215 lb-ft@4200RPM) has less torque with its peak at a higher RPM vs the 2.5L (241 lb-ft@3,600 rpm). That 600 RPM and less torque is quite evident. We rarely rev our LGT past 4000 RPM. The H6 was smoother but weaker and $$$ to purchase vs LGT 05 non-limited manual.

[Ranger83]

And why are you anti-turbo...? Wanting more power does not make you a boy racer. Stock for stock they may be close in the slower speeds but that one car length will continue to grow if they keep going

Sure, that's why Jeff Perrin's turbo H6 (410hp) is interesting. Do you own a Legacy GT, or Outback XT?

 

I have no idea of 0-60 in a LGT Wagon. Its my wife's car. I tried the Outback H6 for a day with her. The H6 felt weaker. The reason why is the H6 (215 lb-ft@4200RPM) has less torque with its peak at a higher RPM vs the 2.5L (241 lb-ft@3,600 rpm). That 600 RPM and less torque is quite evident. We rarely rev our LGT past 4000 RPM. The H6 was smoother but weaker and $$$ to purchase vs LGT 05 non-limited manual.

 

Word is the non-Limited GT wagon with manual may be back in 08. I don't fit under the sunroof so my choices were limited in 06.

 

The XT probably handily outsells the H6 models in the US because of the focus on 0-60 times here, but there is less difference at legal speeds. The turbos respond to tuning and have tons of parts: the H6's have virtually no tuner parts until the aforementioned H6 kit comes out.

 

The guys at TDC say the XT has about 200 whp stock, but this works for me.

 

 

[Virrdog]

Sure, that's why Jeff Perrin's turbo H6 (410hp) is interesting. Do you own a Legacy GT, or Outback XT?

But it still has a turbo and requires premium gas, doesn't that scream boy racer again?

 

I have neither. Good old Legacy Sport Sedan for me. The torque curves on Subaru turbo motors always whip the comparable NA. My 160 hp vs. the 165 hp a 2.5L RS is supposed to have is a joke. From a start I run away and even at highway speeds I just pull away from them. The torque curve plays a big part in this. But to be fair, these cars were under-rated from the factory. Low insurance .

[monk50]

Only old people buy them and they don't know how to use the internet....

 

I have an 05 outback with the H6. So far no problems and an excellent car. I drive up into the mountains of NC and like the power and torque of the 6 cylinder.

 

So far the only disappointment is that the car at times seems to "search" for the right gear. It seems to change gears a little too often. Other than that I love the car.

 

I do not have experience with the 2.5 or turbo only with a 95 legacy.

 

monk50

[Ranger83]

I have an 05 outback with the H6. So far no problems and an excellent car. I drive up into the mountains of NC and like the power and torque of the 6 cylinder.

 

So far the only disappointment is that the car at times seems to "search" for the right gear. It seems to change gears a little too often. Other than that I love the car.

 

I do not have experience with the 2.5 or turbo only with a 95 legacy.

 

monk50

 

If you put the trans in Sport mode, it will upshift earlier and hold each gear longer. You don't have to shift it manually - just slide the lever to the left and leave it there. Makes a big difference in shift logic.

[telemachus]

Not enough 6 cyl. Subies out there yet for me to get one. The new 2.5 beats the crap out of the old 2.2, and both are solid. My GT is plenty of fun to drive with the 2.5.

[nipper]

 

IMHO I agree h6 though will have a lower maintenance costs with timing chain. However I wonder if it will need to be pulled apart like the 2.5L when they spring inevitable oil leaks all over making the timing belt replacement possibily a mute point.

 

 

There is not timing belt, its a timing chain. Therefor you only have the main seal to worry about, and the timing pan gasket.

 

Turbos always have shorter lives then n/a engine. The turbo may be simple, but when it goes, it costs big bucks. A N/A piston engine, especially a subaru should pile on miles like any other subaru engine. Again its an oppsed piston engine, so a lot of forces cancel out. The mmore moving parts is just a silly argument, if that was true, no one would by anything.

 

NOrmally turbo engines have a shorter life then their n/a counterparts, but i dont think thats true for subarus.

 

nipper