Questions about Subaru, first post, loooong reaD
 

Hello :) this is my first post here although I think I may have been hypermiling since before the internet. First car: 81 Accord 5sp. That thing could coast for miles, I wish I still had it. Anyway on to the topic. My 92 accord wagon is broken for now. That leaves my winter car to drive. A 98 Outback legacy wagon with a few simple mods. I have many questions about this car so if any of this has been covered, please forgive me. I was overwhelmed when looking for specific info. First off it is a 5sp and I live around some big mountains so coasting with the engine off is a good option for me. I have been doing it with my Hondas for a long time. My Subie seems to run ruch when I catch it in gear so my question is this. Is there something going on with the computer that forces it into rich mode when I turn the key? Or when the engine starts? Can I please bypass this? It seems to undo some of the fuel savings of coasting. I need to put in an engine kill switch because the headlights go out when I flick the key. soooo...will that help?
Next question. Is there any way to make a manual Subaru 2wd for the summer? I have heard rumors that they can be switched if you have auto trans but no data on the manual. It seems they are both Awd but work differently.
Last question (for now). Will coasting hurt the AWD with my manual trans. I have heard people say that coasting or bump starting is bad for cars in general but AWD even more so. I dont see any reason why this car can't coast and bump start. It has a neutral gear. It certainly never seemed to hurt my Honda's.They all lasted a long time and died from rust and general neglect around 300,000. Any input would be greatly appreciated. These Subarus are a lot different. Thanks!

Here's the URL for what I found to be the best Subaru message board when I was considering getting one:
Ultimate Subaru Message Board

Yes, the auto tranny Subies can be switched to 2WD (front) by pulling a fuse or some such fairly simple method. Of course they're still "autotragic".

As for whether coasting in neutral is bad for it, check your owners manual. If you don't have it, chase one down on the web, as a .pdf or whatever. Usually its OK for standard trannies to coast in neutral, and mostly not OK for autos. But then Subie standards might be different...

The manual will tell you for an auto, you can coast at up to x mph for up to x distance. Usually not very far and not at useful speeds either. You look it up under "flat towing" in the manual, which means towing with all wheels on the road.

My Civic goes into open loop (rich) for about 10 seconds after a bump start. A Scangauge will tell you what's up there, if you have one. There's a readout for open/closed loop status. I'm OK with the 10 seconds when bump starting because my commute is about an hour.

subarus are all wheel drive.

the front axles always turn, the rear axles always turn, the middle driveline always turns, the transmission always turns.

The manual and automatic trans are slightly different in the central differential. On the automatics, the front axles are hard connected to the trans output, and the rear diff is connected via computer controlled coupling. This means the fronts always turn, and the rear propels the car when the computer tells the central diff to help out.

On the manual, there is a spider gear setup to where power goes to "both" front and rear differentials.

On the auto's you can pull the fuse which disables the computer controlled coupling.

Adding it all up, and I really doubt there is fuel savings in worrying about any of this.

The subies are HEAVY vehicles. They don't get great mileage.

On restart, when you hit the key the computer gives an "extra" shot of gas to smoothly start the engine. I don't know what you do to override this.

I don't know that I would consider a 98 outback that HEAVY. For an AWD wagon <3000lbs isn't terrible.

There are ways to convert the car to 2wd, but with a manual it isn't a simple task. As noted above, the savings are going to be negligible, unless you are removing all of the drive-line components associated with the driven wheels you are disabling.

Related question: Which engine does the car have - the 2.2 or the 2.5? If its the 2.5, have the headgaskets been replaced? If so, when?

Coasting will not hurt the manual tranny. I've put hundreds of coasting miles on my old Su and it was going strong until rear ended at 240,000 miles. I also noticed a strong smell of gas when starting after a long engine off coast. Don't know what to say about that. Might not be good for the cat, but mine had died 100,000 miles before.

As drmiller already pointed out, all that driveline stuff is spinning anyhow, so not putting power to it will make no difference.

While on this topic, I wonder of Subaru will ever reverse their decision to go 100% AWD.

They are competing directly with all the other manufacturers in segments where AWD is of little or no benefit and has very measurable liabilities.

i realize that there is some benefit in reducing numbers of assembly lines, but, they make enough cars that that shouldn't be a big issue. I suspect it is more of a marketing gimick as it is with Audi.

The Subaru BRZ is RWD and is currently one of the fastest selling cars in the US.

Oh yeah, forgot about that one. Just read an article about it, too.

Anyway, that model is a little different in that it is a joint venture with toyota. I wonder if they will go back to FWD models of their current AWD platforms.

Seems like it would make sense in the brutally competitive midsize sedan market. Also, I think it would help them in the traditional station wagon market since this market is largely ignored by the other makers.

It's not that heavy for a Subaru, but it is quite heavy for a mid size car.

curb weight is more like 3500 pounds.

No, it's really not. It's about the same as a Maxima of the same year or a base model Accord wagon, and it meets that standard with AWD and all of the basics including PW and PL standard. By the standards of many on here running Civics, Saturns, and Metros, yeah, it's a heavy car, but it's actually a light vehicle for its size.

OP- As others have mentioned, the AWD is basically permanent and pretty nearly indestructible. It is possible to remove components and convert it to FWD operation. I had a neighbor growing up who had a FWD '95 Legacy. It had been a program car of some sort, and it was that way from the factory, so it certainly can be done reliably. But it's probably not worth it to take the driveshaft, rear diff, and axles out just to gain a little bit of MPG for the summer and have to put it all back for snow driving.

Bump starting never caused any trouble for me when I had an Outback. I wasn't doing a whole lot of hypermiling back then, but there was a long hill on my way home that was perfect for EOC, so I used that technique a fair amount. The engine and transmission worked great until I totaled the car around 200k miles.

3155 lbs. I was slightly off, it's about 100 lbs. more than I thought. So, along the lines of a Maxima with auto trans and slightly lighter than an Accord EX wagon.

1998 Subaru Legacy Specifications

My bad, I was looking at the Brighton, not the Outback. 3155 still isn't terrible for an AWD wagon.

We recently had a lightweight wagon thread on GRM, and could only name 6 wagons under 2750lbs made after 1990. Only 3 under 2500.

The 2WD fuse doesn't do anything as far as mileage for the automatics. You also can't coast with the engine off as the center differential will melt quickly. It's not a problem in the manuals, however.

My old test with the FWD fuse:

http://ecomodder.com/forum/showthrea...awd-10755.html

What ever it is that the subie weighs, it would weigh considerably less if it lost half of it's drivetrain. I would think that the transfer case, drive shaft and rear end must add a minimum of 100 lbs. I would think the actual number is more around 200.

Wow, Thanks everyone. A lot of help here. I think some of these questions would draw a blank over at the Subaru forums. Most people just don't even get what I'm talking about! Sooo...I figured it would be ok to coast with the engine off. It is a manual after all. As for curb weight I've done a few simple things to reduce it. Since I use it for cargo it may be a moot point but, the rear seats are on wing bolts so I can have those out in 3. I deleted the roof rack and put some clear lexan over the goofy inset fog lights, I use an upper grill block in winter. I would like to find a plain hood but for now my scoop is covered. My hood weighs more than me so, do you think it is safe to cut it down to a single layer of sheet metal? It's pretty thick so I think it will hold up. I have the 2.5 engine and I have had no problem with head gaskets at 140,000. It seems that I keep my radiator cleaner on the outside than most and I never Idle so, along with A/C delete that solves most cooling system probs. I live around big hills so you have to know the limits of any vehicle lest it or you die fast. Car runs good actually. Best mileage and curb weight you can get on a car that will pull 5 people,luggage and a loaded trailer over an icy mountain at 70 mph. (this is hypermiling because of the amount of work done by a single vehicle) I wonder if my Honda Accord wagon from 1992 was on that list of wagons under 2700 curb weight? Also a very,very good car. Almost the best hypermiler I've owned but I think my little 81 accord fastback took the cake. I need a wagon for a lot of reasons so my choices are limited. What I would really like to do is use that extra output shaft on the center diff to put a motor on and make a hybrid out of this car somehow. What a sleeper it would be with about 50 extra horses on tap and the ability to regenerate while coasting :P Any recommenndations on a suitable motor for cheep?

Warning: Heavy brainstorms ahead.

I always thought it seemed like a good idea to have a FWD gas car with an electric motor driving the rear wheels and doing some regenerative braking. It's probably beyond the scope of what you want to do with this car, but I would like to, someday, find a Legacy rolling chassis, put a native FWD (transverse-mounted) drivetrain under the hood, and do exactly what you're talking about with the rear wheels. That would do away with the additional drivetrain losses of RWD over FWD (from changing the plane of rotation), retain AWD functionality, and gain the advantage of a light hybrid system. I would only do a small cell due to weight concerns, just to help out under load, recover some lost braking energy, and maybe get it up to idle in 3rd gear from a stop before kicking the engine in. If you're clever, you can probably fit the whole setup under the rear floorboard and above your eventual ideal bellypan, so you don't sacrifice aerodynamics or cargo capacity.

I'm not sure what motor to use, or even where to start looking, as I've never done an extreme drivetrain surgery like that, but you might have more room to play with if you turn the differential around and mount the motor behind it. You might have to sacrifice the spare tire area, but you could avoid having anything enter the actual cabin. Thanks to the brilliant symmetry of that drivetrain, the diff reversal shouldn't even require any body modifications. Just remove it, turn it around, and reinstall it. Might help, might not. At least you have that option to play around with.

Good idea with the spare tire area orangustang. Space is def. at a premium on this car. I was planning to leave the awd intact at this point because there doesn't seem to be a way to control the speed of the rear output shaft on the center diff. Adding a motor in the spare well and getting it to power to the rear diff input seems feasible though. The rear diff is mounted solid to the chassis unlike a truck and has a nice 4 bolt input flange :) Does anyone know if there is enough sliding room in the rear driveshaft to allow bolting in a pulley say an inch thick without shortening it? Now...where to find the right motor?

BTW...still looking for a hillbilly way to get rid of the rich burn bump start problem. Scanguage is nice but I would like to save money. Would a fuel pump cutoff be possible? Any suggestions for wiring?

Seems you have answered the question already. The sedan market is brutally competitive, so why would Subaru offer their own flavor of what is already offered by everyone else? You might as well ask why Jeep isn't entering the FWD sedan market. There are already cars there; lots of 'em.

Subaru has built their reputaiton and distinguished themselves by having AWD cars. Their AWD cars are darn good for those who need them, or those who buy into the marketing idea that they are safe.

I don't think Subaru needs a different strategy, and I certainly wouldn't confuse customers by offering 95% of vehicles in AWD, but some in other configurations.

You may be able to turn off that feature threw the ecu? just a guess.

IMO, best starting point would be a Civic. You can keep the transverse FWD section and use the very lightweight rear drive-train section from a CRV or the late 80s Wagovan AWD model. There are a few AWD conversions floating around on the web for Civics and there are enough parts that they don't require serious fab-work that I know of.

Maybe you are right, but, as fuel prices get higher and higher, the desire to get every MPG possible becomes more important and I think trumps the desire to have AWD, especially for the majority of owners who honestly have no need for AWD.

Subaru makes enough cars that their engineering/manufacturing capabilities won't be spread too thin by the added models. And I doubt their very loyal customers will forget that they've got a little experience with AWD.

I think the biggest question is, does the added cost of additional lines raise the price of their AWD models more than a few bucks. if it does, then I agree that it makes sense to stick with an AWD only lineup.

Thanks everyone. ecomodded, It seems altering the ecu would be exactly what I want but I have no idea even where to begin. I was hoping to be lazy and find someone who already knows how. Pete c. I have to humbly disagree with you that Subaru has the engineering/manufacturing capability to design and build more/different cars. Just my opinion but from what I've seen they are very slow in releasing new designs and a bit smaller than the competition. Redpoint5 is thinking like the big wigs at soob. I for one would like to see them release FWD or even RWD as an available option on all their models. No confusion. You just order the thing the way you want. They would be rather expensive for a 2wd vehicle though. ProDarwin I like your Idea and agree a civic is a great, great car for mileage but I don't have one. I used to have a wagovan and loved it but the rust ate it so completely that it wasn't safe. I do have an accord wagon so a link to some of those parts would interest me. Right now though I am broke and I need my Subie for the snow and mountains and off road. A quick note: Redpoint5 mentioned the safety factor of the Subaru AWD and I can personally vouch for this after a near miss in which I simply used the shoulder to avoid an accident happening in front of me. The legacy wagon is absolutely incredible at soaking up huge bumps and staying stable and in control while carving a four wheel rut through the wet grass at 60+ mph. Definitely safer than a truck or suv and more able than a car. My girlfreind was with me and wants one now too.