better fuel milage

[jettyrat]

i have a 98 forester and a 99 outback both get 25 mpg any suggestions for better fuel milage

[Red92]

i have a 98 forester and a 99 outback both get 25 mpg any suggestions for better fuel milage

 

I'll just go ahead and re-use one of my old posts for this.

 

Pumping up your tires a bit more will help lower rolling resistance. I'm not sure if any of the special low-rolling-resistance tires are available in the Subaru sizes, but narrower tires would help as well.

 

Depending on how you use the vehicle, you can also improve performance & economy by shedding weight. Some of these can get a bit extreme for a daily driver, but if you only use it for a commute vehicle, they may be tolerable. Things like removing the air conditioning system, removing the rear seats, removing carpeting, etc. Even just running with the gas tank half empty is good for 50 lbs! Keep it at 1/4 or less, and that's 75 lbs of extra weight you are not hauling around all the time! If you have a roof rack, you can remove the cross pieces to be more aerodynamic. You could probably drop another 15+ lbs by downsizing the battery.

[bheinen74]

Tuneup.

change air filter every 8k

use full synthetic oil

belly pan custom made to reduce air turbulance

tire pressure increase as stated.

take off any roof racks crossbars

add full disks to cover the wheels (yes look at any experimental cars and you will find smooth wheel surface is key)

etc.

 

use good grade of gas

use synthetic gear oils and if you have ATF synthetic.

you could modify the front grille for better aerodynamics too.

lowering the vehicle will help too.

 

Make sure you have the O2's changed to new oem.

new knock sensor

bearings going bad can cause drag so new bearings

make sure brakes are serviced and sliders lubed, you don't want any brake drag at all.

 

disable daytime running lights

keep fan speed off or low at all times

keep AC off

do not have uneccessary current draw on the alternator (get rid of amps, radio, subs speakers, also saving weight etc)

if you have a hitch remove to save weight.

get rid of spare tire to save weight.

You could change to a SVX final drive, 3.54 ratio, for sure that will improve mileage.

that is all i can think of.

Edited November 21, 2011 by bheinen74

[Red92]

that is all i can think of.

 

... but I see that you keep adding more.

 

 

If you get rid of the spare, you can also get rid of the jack and the lug wrench.

 

I'm not sure how much the stock wheels weigh, but I bet you could find lighter wheels too.

 

You could install electric engine block heaters, to help the engines get up to efficient operating temperatures quicker when it is cold out.

 

 

Going more extreme, can the Forester be converted to 2WD, to eliminate the driveshaft, rear (and center?) differential(s), axles, etc?

Edited November 21, 2011 by Red92

[ergo]

Rather than gut the Subes to make them more fuel efficient but less practical and user friendly maybe it's better to just replace them with high mpg cars;)

(installing narrower tires makes for much poorer handling and traction, especially in rain, removing air conditioner means sweltering in 100plus degree summer weather, and enduring continually fogged up windows in rainy, icecold weather, especially with 3 or 4 passengers.

Lets face it. Most Subes just generally get stinko mileage. It's the nature of the beast. Either get used to the lousy mileage or get cars with high mpg instead.

[Redcap]

Rather than gut the Subes to make them more fuel efficient but less practical and user friendly maybe it's better to just replace them with high mpg cars;)

(installing narrower tires makes for much poorer handling and traction, especially in rain, removing air conditioner means sweltering in 100plus degree summer weather, and enduring continually fogged up windows in rainy, icecold weather, especially with 3 or 4 passengers.

Lets face it. Most Subes just generally get stinko mileage. It's the nature of the beast. Either get used to the lousy mileage or get cars with high mpg instead.

 

[NoahDL88]

Spending thousands of dollars on getting a few more mpg's isn't a good return on your investment. Check out the hyper miler sites, changing your driving habits will have the biggest impact on economy.

 

A tune up won't hurt if it's time and checking the pressure in your tires is a good start.

[danbennett2u]

25mpg is about right for these vehicles in mixed driving. As others mentioned subarus in general arent extermely high mpg vehicles ( the ratings for the 2012 impreza do impress me though) I would be surprised if you get more than 27 or 28 regardless of what you do to them, unless you are driving it on the highway exclusively for the whole tank (one speed up to hwy speed, only stopping when refueling as in a long road trip)

[86subaru]

or ride a horse and buggy ,which i do

[ergo]

or ride a horse and buggy ,which i do

 

Very sensible, let's all go Amish!

Edited November 21, 2011 by ergo

[rverdoold]

I was interested in the consumption of using the lamps all the time. Well for a 30,000 km (per year) it consumes about 8 liters of propane. Nothing compared to my 2,800 liters of propane I need to drive that distance.

 

A/C is the word and so is your right food. I try to drive 55 and avoid to use the brakes as much as possible. On off-ramp coast as soon as you get on there. Shift when you reach 2,500 RPM.

[jdemaris]

Rather than gut the Subes to make them more fuel efficient but less practical

 

From all I've owned the older Subarus were the ones that were more practical and had less sillly frills. They also had better fuel mileage.

 

My Loyale 4WD wagons with 1.8 engines and 5-speed manuals often got better then 30 MPG on the highway AND would go places few of the new Subarus will.

 

My 1.3 liter Justy 4WD got even better miles but was pretty tiny.

 

My mid-90s Imprezas with 2.2s all got around 26-27 at best.

 

My 2002 Impreza with the 2.5 tends to get 24-25 MPG. It's fun to drive on a paved road - but I can't take it in the woods or up in field like I did with my Loyales. My neighbor has two Foresters with 2.5s and he's never even gotten 25 MPG.

 

So what is really practical? To me it's a 4WD Loyale with a 1.8, high-low range transfer case, and air suspension to get extra ground clearance when needed.

[Fairtax4me]

Fel lucky. The best I can get out of my 95 L wagon is about 23. And that's on the highway.

[the3rsss]

If you compare other makes and models IN THEIR CLASS, you will find that the awd subaru get decent mileage.

[subynut]

Yeah, the AWD certainly cuts into the MPGs. Best thing to do is change your driving habits - don't be the first across the intersection and do 70 instead of 80 on the interstate.

My blue 87 gets 30-35 on the highway, but 75mph can be a chore with any hills or headwinds. The PandaWagon in all it's swapped glory gets an average of 28mpg. I've gotten up to 34mpg cruising at 55-60.

The 2012 Impeza with the 2L and CVT will be interesting to see what the average mileage will be.

My biggest gripe driving slower than the speed limit is that most people on the interstate are doing 5-10 above the speed limit. So, if I am doing 5 under, that means they are doing 10-15 faster than me - I could be putting myself in danger with all the distracted drivers out there on the interstates as they approach my "slow moving vehicle" while reading they're latest text message.

[tonloc152]

I have thought about putting in the awd bypass fuse and running the wagon in front wheel drive. Has any body done this for an extended period and what were the results? I plan on running in 2wd all summer and then swith back to awd for the ski reorts here in Utah for winter.

[bheinen74]

I have thought about putting in the awd bypass fuse and running the wagon in front wheel drive. Has any body done this for an extended period and what were the results? I plan on running in 2wd all summer and then swith back to awd for the ski reorts here in Utah for winter.

 

This is a proven way to kill duty C solenoid.

 

This is a good idea and Subaru should start making them FWD, with the push button to go to 4WD, kinda like they used to make them. If engineered this way people could go to AWD only when they really need it. It would save many MPG in the long haul.

 

I hope SOA monitors these boards every now and then.

[NoahDL88]

The whole advantage of subaru's awd system is that it is always ready, if I wanted part time I'd get a truck. Subaru is the best compromise of snow capability and fuel economy.

 

To your other point, subaru only reads the boards for trademark infringement, they could care less what a bunch of cheap bastards are doing to cars they haven't made in twenty years

[jdemaris]

If you compare other makes and models IN THEIR CLASS, you will find that the awd subaru get decent mileage.

 

We went on a 400 mile trip in my father-in-law's Ford AWD Escape with the 2.5 and 6 speed auto trans. Four adults, one kid, one dog, and gear. The old man has a heavy foot and we did 70 MPH most of the trip. Got 30.5 MPG. I'd call that pretty good and better then any newer Subaru I've driven. His previous Escape AWD with the high-output 3 liter V6 and 4 speed auto got 27 MPG on the same trip.

[jdemaris]

The whole advantage of subaru's awd system is that it is always ready, if I wanted part time I'd get a truck. Subaru is the best compromise of snow capability and fuel economy.

 

I drive in some of the worst ice and snow conditions available. I live on a seasonal steep mountain road that never gets deicer on it and gets deep wind-driven snow drifts. My older part-time Loyales went places my newer Subaras cannot. No contest. If Subaru was the "best" it would have a lower 1st gear (in manual trans cars) or a low-range option. Also should have some sort of severe-weather wheel lockup system so you can actually get full power to the front and back drive when needed. Also maybe some better ground clearance option?

 

When General Motors first came out with their AWD full-time trucks and SUVs in the late 70s - they had all that. Hi-low range and a regular AWD mode and a severe-weather AWD lockup mode. I'd love to see that in a Subaru.

 

I find one thing to be true with all my Subarus thus far. Holding the road coming down ice-covered mountain roads. I've driven my Subarus down my ice-covered road when many other cars and trucks would spin like tops and go into the woods. So, it's not the medium-good going ability . . . it's the stopping ability and holding the road ability. I tend to use Subaru wagons but . . . I did have one 2 door 4WD Justy that weighed almost nothing. Surprisingly, it held the road as well as my wagons. Yet I have a Geo Tracker 2 door 4WD that is a death trap in the same conditions.

[rverdoold]

I have thought about putting in the awd bypass fuse and running the wagon in front wheel drive. Has any body done this for an extended period and what were the results? I plan on running in 2wd all summer and then swith back to awd for the ski reorts here in Utah for winter.

 

Since there are no unlockable axles you will always drag the whole drive train. Even if on the automatic the FWD fuse is placed the drive train drag is there.

 

I am not sure if new cars actually have a lockable diff or just a ABS that stops the spinning wheel so the diff transfers the power to the other axle. In our toyata yaris MMT (manual computerised gearbox) this is called electronic diff lock. And is only there because you can not operate the dry clutch to play with the slip of the wheels as you can do with a full manual.

I am not bothered with the AWD extra fuel consumption, subaru should introduce smaller displacement engines with turbos. Like 1.5 turbo, maybe 1.2 turbo. I love my low power 1.6 with hi-lo gearbox. Never got stuck in mud and snow/ice.

[jdemaris]

Since there are no unlockable axles you will always drag the whole drive train. .

 

I suspect even if you could take all the extra parts out it would make little difference. I've got a 1998 3.8 Dodge AWD Grand Caravan. A friend of mine has exactly the same model and year. We were getting a best of 23 MPG . He took out his rear driveshaft and rear drive axles. Guess what he gets now? 23 MPG.

 

What I don't understand with the newer Subarus is lack of proper gearing. Manual trans cars do not have a low enough gear for good starting on steep hills and none seem to have enough overdrive for good fuel mileage. I can understand an underpowered car not having a lot of overdrive - like my 1.8 Loyales. But take my 2002 Impreza Outback 2.5. It has lots of power and could greatly benefit by getting the final RPMs down to 2000-2200 (like my Dodge van does). My five-speed manual trans 2002 Impreza in 5th OD spins the engine at almost 2800 RPM at 65 MPH and that is rediculous. What the heck are they thiinking? By the way, my father-in-law's Ford AWD Excape - also with a 2.5 - turns 2100 RPM at 65 MPH.

Now my 92 Loyale with the 1.8 turns 3200 RPM at 65 MPH but that IS underpowered a bit. If my 2002 Impreza had proper overdrive, I'm sure it would exceed 30 MPG on the highway.

 

In regard to traction - Subaru offers on some models their DCCD. That is a driver-controlled differential adjustment between the front and rear drive. But even that offers no lock. It just defeats the computer and lets the driver choose which end of the car gets the most drive-power to the wheels.

 

Now the old Loyale 4WD, IF standard shift did have the front and back locked when needed. Oddlly though, the 4WD with three-speed automatics didn't really have that. It used a weird throttle-sensitive control that activated a rear-drive hydraulic clutch pack. The harder you hit the gas, the more power to those clutches. A real bad design.

[jettyrat]

thank you all for the suggestions some i can use some others i cant. You see i like to surf fish and take the forester out on the beach, and it does an awsome job in the sand, and i also like the raised eyebrows from other surf fisherman with bigger 4wd. I have a 180 mi trip to the beach, one way that is , and take the forester out on the beach all day I'll get about 23 mpg, that with the drive to the beach on 95% highway, thats not bad cause driving in the sand is like draggin a full size pick up behind you on the road. I guess i struggle with the whole gas milage thing with any car, when we can send a craft to mars and control it from earth there is no reason a chevy suburban shouldnt get 50 mpg, it just big oil co. screwing the little guy.

[subynut]

A suburban will never see 50 mpg, the laws of physics won't let it at the speeds and acceleration rates most Americans drive at. You're talking a 6000lb brick you're shoving through a fluid that does not want move out of the way. Now, with a small six, CVT, lowered, removed mirrors and roof rack, belly pan, and do no more than 50mph, you might see 40 mpg with a tail wind. However, do you really want to be the slowest SUV on the road?

With the technology we currently have, Mars is about the distance we can go. Just as the Moon was the farthest we could go back in the sixties. This is the bleeding edge of technology, which takes over the top funding to supply the equipment, knowledge, personnel, and time needed to do projects like these. Ever calculated the difference .1 degrees makes of where you end up at a distance of a million miles?

Until (or if) scientists figure out how to get to and beyond the speed of light, we are stuck with go fast and use more fuel or go slow and use less fuel.

We Americans are speed demons. We want to go fast, turn fast, go anywhere, and haul anything all a the same time while spending as little as possible at the pump. It doesn't work that way. If we want good mileage, we first must slow down.

Our Subarus are all weather vehicles - We sacrifice mileage for traction and stability. If you are a Subaru freak, like myself, then you must build a high mileage Subaru by sacrificing the all wheel drive for FWD, use the most efficient Suby engine out there with a tranny that has a good overdrive, and put it into the lightest and most aerodynamic shell Subaru built. The reality question is: If you are getting an average of 10 mpg more than a stock Subaru, how many miles will you need to drive that car to make up the cost of building such a high mileage Subaru? Is it cost effective? Probably not, but it would be a fun project!

[rverdoold]

If you are a Subaru freak, like myself, then you must build a high mileage Subaru by sacrificing the all wheel drive for FWD, use the most efficient Suby engine out there with a tranny that has a good overdrive, and put it into the lightest and most aerodynamic shell Subaru built. The reality question is: If you are getting an average of 10 mpg more than a stock Subaru, how many miles will you need to drive that car to make up the cost of building such a high mileage Subaru? Is it cost effective? Probably not, but it would be a fun project!

 

This always wondered me the AWD vs FWD, now in Holland you can get the impreza 1.5R with FWD only. It needs 6.1 liter/100km, which is 38.56 MPG for out of city. However, the 1.5R AWD is rated at 36.75 MPG (according to the same standards). These both are manuals. The 2.0 AWD manual is 34 MPG while the automatic is 35.6 MPG. So on the long go more efficient. The diesel version gets about 48 MPG. The STI only gets 28 MPG.

 

I personally get with my 1.6 AWD impreza station about 28 MPG on propane and about 33 to 34 on regular fuel. The propane consumption is over 2 years and the fuel over about 2 months (5x refil). My old 1991 FWD legacy automatic got 28 MPG over 5 year average!!! Including city driving and alpine holidays.