A Quest for 35mpg (Subaru Outback Limited Sedan 2.5L auto)

[cosmic_kid]

Can you buy ATF online anywhere? I can't find anything nearby.

[brucey]

Dostimar: I don't' know about the newer (08+) transmissions in the 6 cyl legs and OB's, but the one in the SVX is transferable to an outback, and vice versa with almost no modding. Plenty of guy sare running SVX's with outback transmissions for it's 4.44 gearing. In fact, it might be worth looking into because the SVX came with a 3.54 or something like that. But it did have a different rear end than the standard sube one. And the 4EAT H6 OB's of my cars generation is the same +/- the gearing, but the center differential is different so it'd probably be easier to find an H4.

[d0sitmatr]

Originally Posted by brucey

Dostimar: I don't' know about the newer (08+) transmissions in the 6 cyl legs and OB's, but the one in the SVX is transferable to an outback, and vice versa with almost no modding. Plenty of guy sare running SVX's with outback transmissions for it's 4.44 gearing. In fact, it might be worth looking into because the SVX came with a 3.54 or something like that. But it did have a different rear end than the standard sube one. And the 4EAT H6 OB's of my cars generation is the same +/- the gearing, but the center differential is different so it'd probably be easier to find an H4.

good to know, I hadnt heard that before. if I had known, I probably would have gone that route as there was 2 SVX near me for sale at the time for less than $1,000.0. maybe I could have just pulled the FD from the AVX and used it in the OB ?

zerhour
I never once considered turning the car into an RWD. mostly because of things I read on the OB forums, where the car has a fuse you cna pull that disables the RWD of the car, essentially turning it into a FWD. but that isnt much of an option as it is an emergency feature in case of a problem with your rear transaxle, and actually takes away your FE by quite a large margin.
but a RWD OB would def be an alternative. and a preferable one at that (for me)

[Zerohour]

I'm pretty sure it would take some overhauling to get it done. But Once you remove the front diff ring, the the drive axles, there is only one place for the power to go. lol Of course I'm not sure how much the subaru would like this. I would definitely need to see what the internals look like to see if it would be a feasible idea.

[evilskillit]

Careful, you can read adventures of Imreza and WRX guys running their car for RWD fun for hoonage or autocross. The rear axels and diffs on those guys weren't really designed for that sort of thing and have been known to break if run very long or abused under those circumstances.

I've never done it before but I've read about it, you'll want to ask around on some Subaru owners groups forums if you're really going to give it a shot. Then again be prepared to catch a lot of flack for wanting to change one of the main features that makes it a Subaru, those guys can be rabid.

[d0sitmatr]

indeed they can

[Zerohour]

So the Mobil 1 Synthetic in in the trans pan and new filters are installed.

I got 6 quarts out of the trans with a 9.8 quart capacity. So the fluid is more or less 60% synthetic. A simple drain and refill would yield about 4-4.5 quarts. Thought about doing an additional flush, but I don't think its worth it for another $40. But I'll swap out synthetic with more synthetic at the 30K interval.

Initial reports, it doesn't shift any different. So thats pretty much a good thing. LoL When most people reports improvement on the trans shifts after fluid its due to bad fluid and excessive wear. I had very little debre in the bottom of the pan. There was alot stuck on the magnet, and everything had a light layer of grime. So it was due, but not gone! So I got it changed at a good time.

I am interested to see if the fluid reacts differently in the morning. But I won't know till tomorrow's commute. I'll post back the results then.

Also, my Subaru outback/legacy manual states my power steering unit uses Dexcron II/III ATF fluid. I have extra left over from the change, and I seriously considering swapping this out as well. If the ATF fluid causes FE loss in the cold, then the PS pump is lugging that motor as well. So the switch to the syn ATF might get more a little be more at cold start-up's!

[Zerohour]

Swapped out the PS fluid as well. The fluid inside was changed at one point. The ATF still smelled fresh and only has slight discoloration. Oh well, least I know I checked up on the maintenance and got little synthetic in the pipes.

I'll post back tomorrow to see how it does.

Also got the TR7 a little bit further along. I still need new e-brake cables, speedo cable, and reverse light switch. Also discovered the hose clamp on the radiator was loose and I've been slowly leaking anti-freeze out of the car... :-( Clamp is back on and I need to stop at the parts store tomorrow and pick up some more antifeeze. I'm kinda piss at myself for not noticing something so obvious and of course for dumping the antifreeze around the dirt driveway for the past few months.

[Zerohour]

So after three morning runs I can say this, weather in PA is rubbish.

Monday Morning: 57
Tuesday Morning: 59
Wednesday Morning: 63

So much for testing it in the cold. I can say that the trans still seems to hold the gear while the engine is cold. I fear the trans is controlled more by the engine temp than the actual load on the trans. But its hard to tell because We haven't hit below 50 in three days...Besides that trans is still working normally. :-)

Oh well. Unless it gets cold again soon, I won't be able to give immediate results of the a difference in warm up times.

I'm starting to consider full synthetic motor oil as well. Right now I'm running Valvoline Durablend (synthetic-conventional blend).

A bit of good news is that my LED guage light works after swapping to a different led...the bad news its now so bright its actually back to the same issue I had the with the filament bulb. And it makes a glare on the windowshield. oh well at least its green and matches other lights. I do need to make a cover for the back of the gauge. The new LED holder has a transparent stopper. so I now have forward facing green light. *rolleyes* i'm sure its only a matter of time before I picked by a local twit cop for having the green light on the dash. I'll be fixing that up on Friday.

Two more projects are in the works. And I'm thinking up a third and a fourth. All are hush hush for now! :-p

[Zerohour]

Due to lack of motivation and it being too cold to piss outside, I've gotten lazy. :-(

But I would like to note the following:

Achieved 28.84mpg on a trip to DC for the Stewart/Colbert rally. The trip down we drove like a nutter. 70-80mph going through traffic and passing on hills...I was playing follow the leader with a car full (4 people + light luggage). Ride back was moderately safer maintaining a 65-75mph speed. Temp ranged from 28F to 50F during the trip. Gasoline was E10...non-ethanol has gone dry except for one 93 octance source.

I'm fairly happy with the results considering! Back in June when it was 55-60 in the morning and 75-80 during the day I was getting 24.5ish mpg. Now I'm managing 25.5ish in the moderate beginnings of the cold. Last year at this time I was in the 22-23 range. Overall I'm not sure what effects I'm having due to school buses littering the commute route vs. mileage last year going mainly highway at off peak times. I would like to imagine the aero mods are doing more than 1-2mpg, but alot may/may not account for my driving.

I keep catching myself driving faster again opposed to the old man rollin' I was doing in August/September. I can't tell whether its better for the subaru to go 35-45 at 1.4k-2k revs with 8psi of vacuum or if its better to try to keep up the speed and do 50-55 at 2k-2.3k with 10-12psi vacuum. And as Brucey has mentioned doing 55-60 keeps the TC locked up and you get better mpg's. But traffic/weather is so inconsistent I can't make any definite conclusions!

Thus I popped an eco-cherry and ordered an Ultra Gauge tonight. :-)

I am also trying to review dates of when mods were installed versus the decrease in consumption. Overall I have had a net gain, but its hard to tell what may have helped versus what may not have helped.

So here is the up to date list:
Aero:
*Lower grill block
*Front wheel side deflectors
*Lower bumper air deflectors
*Wheel skirts
Engine:
* Warm/Cold Air intake (modified filter setup)
* Modified Exhaust
Suspension
* 38 PSI on Yokohama Envigor All-Seasons
* 22mm rear sway bar (can coast/maintain higher speeds through corners)
Fluids:
*Synthetic blend Oil
*Synthetic blend Differential fluid (front and rear)
*Full Synthetic Trans fluid
*Full Synthetic Power Steering fluid (Subi uses ATF)
Instruments:
*Vacuum/Boost Gauge with LED Lighting (saves 2.7 watts!)
*Ultra Gauge (now on order)