I'm wondering if my car needs a tuneup, as it doesn't get the same kind of mileage it did when new...

 

I've got a '99 Outback, 2.5 liter. It get driven almost exclusively on country roads, cruising along from 50-60 MPH. Not exactly interstate driving, but definitely not city stop/go either.

 

I get anywhere from 21 (winter) to 26 (summer). IIRC, that range used to be more like 25-29 when the car was new.

 

I replaced the O2 sensors last year, and that didn't help.

 

It has 95K miles on it. Is this the mileage I should expect, or is it time for a tuneup? New timing belt?

 

Thanks.

try all of the ignition related parts, plugs and wires, then maybe a new air filter, and run some fuel cleaner through your tank. that should help at least some, but it might just be the car getting old.

if the timing belt has never been done now is the time. highly unlikely that would affect mileage, i've never seen timing belts do that. water pump should be replaced and timing pulleys checked (they run out of grease basically). any noisey or free wheelin' ones should be replaced.

 

onto the gas mileage -

has it ever had a tune up? get new NGK (stock OEM) spark plugs, new OEM Subaru spark plug wires, air filter, fuel filter and PCV valve. do it all at the same time, easier to keep track of what's been done and you'll know all major items are addressed.

 

also check tire pressure and have the transmission fluid replaced (if it's an automatic). manual trans too can be replaced, but less likely to affect driveability in my oppinion assuming everyting is working properly.

onto the gas mileage -

has it ever had a tune up? get new NGK (stock OEM) spark plugs, new OEM Subaru spark plug wires, air filter, fuel filter and PCV valve. do it all at the same time, easier to keep track of what's been done and you'll know all major items are addressed.

 

also check tire pressure and have the transmission fluid replaced (if it's an automatic). manual trans too can be replaced, but less likely to affect driveability in my oppinion assuming everyting is working properly.

It's never had a tune up. I replace everything according to the owner's manual,

so the parts mentioned above were all replaced last year (except the plug wires, which I believe were replaced at 60K).

 

So, given that the parts have been serviced properly, am I looking at a tune up?

 

Thanks!

let's define "tune up"

what are you referring to when you say tune up? cause i don't even know what i mean!

 

tune ups aren't like they used to be. used to require adjusting the carb, grease some zerk fittings, adjusting the timing and other things that i'm not old enough to know about...etc. but kind of like your old lawn mower that never really runs right....well not really. modern cars don't require the tweaking older cars did. but there's money to be made by advertising "tune up". sounds like something you should do but it's really quite vague and allows for lot$$$ of padding in the cost.

 

if you've done the plugs, wires, air filter, fuel filter and such then you've done a good job at having a basic tune up.

 

have the PCV valve replaced and consider the wires though i don't think those are cause for alarm. be sure to replace those with Subaru OEM wires and check the air filter. and consider having the transmission fluid replaced. has the trans fluid ever been replaced? check the belts, a stiff pulley (a/c or otherwise) will usually start to cause the belt to slowly disintegrate and you'll see fine black dust on the a/c, alternator or some other item close to the belt.

 

couple bottles of fuel injector cleaner might not be a bad idea. try replacing the gas cap or having it tested (some emissions inspection stations can test your gas cap).

 

are you positive it's vehicle related and not related to a job change, gas changes, elevation, less flat road driving, speed related, odometer discrepancy, lead foot related....lots of variables. subaru's should hold their performance levels to 100,000 easily.

I'm wondering if my car needs a tuneup, as it doesn't get the same kind of mileage it did when new...

 

I've got a '99 Outback, 2.5 liter.

I get anywhere from 21 (winter) to 26 (summer). IIRC, that range used to be more like 25-29 when the car was new.

 

 

Thanks.

 

 

Back when the car was new we also had better gas. In the last few years gas has been getting "odd" to say the least. i think your mileage is accpetable.

 

nipper

I've got the exact same car (5 speed) with 183,000 on it. I've been getting between 25 and 27 consistently, with a mix of highway and city.

sounds like you've been caring for the car. I have the same year and model, and think my mileage is also not what it used to be. I think the problem is the gas and not the car.

 

I remember when they first brought cold weather formulated gas to NH. I had a honda at the time, it was getting 410 miles to the tankful. The very first tankful of the new crap...er...cold weather formulated fuel lasted just over 330 miles to the tank. In fact, I ran out of gas for the very first time in my life thanks to that [bleeping blankety blank] stuff in that first tankful. I thought my gas guage was broken.

 

And it is supposed to cut down on pollution? How? When it takes 18% more fuel to do the same amount of work it did before?

 

They kept on mucking around with the formulation, and I never did recover that mileage in any of the subsequent renditions.

How's the plugs look?

 

Could be a bad temp sensor is causing it to run rich.

 

Lots of sensors affect the gas mileage.

 

If the plugs look good, make sure your brakes are not draging and the wheel bearings are good.

If the plugs look good, make sure your brakes are not draging and the wheel bearings are good.

ah...great point. my mileage went up last summer by about 2/3 mpg after doing a brake job on my 1997 impreza outback sport with 70,000 miles. it had always gotten about 25 since i got, i hadn't had it very long so i figured that was normal. i never noticed anything wrong with the brakes, but after replacing the pads my mileage went to 28. this is on all highway/road trip comparisons. be sure to grease the caliper slides when doing a brake job. if they are dirty at all that will cause the pads to ride on the rotors more. like i said, mine had nothing wrong with them except the pads were low. calipers and rotors were perfect and i only replaced the pads (and greased them slides!)

I have a 97 OBW, 125k miles, runs beautifully. Unfortunately it gets most of its miles in town these days, and we average about 19mpg. However, on long trips on the freeway it jumps to about 27-28mpg.

How is your tire inflation? Poorly inflated tires are the one item responsible for the most wasted fuel. And it's one of the easiest remedies. Also driving habits (heavy on both pedals), AC use, and unnecessary loads. Just basics like that.

 

Try cleaning out the throttle body. It's not on the periodic maintenance but it ought to be. And check or replace your vacuum lines.

dump a can of sea foam into your pcv valve, your car will LOVE you for it

i have a 97OBW with 183,000 auto i get 19 in town, 23 mixed and who know as it hasnt been on a good highway run since i bought it. you sound about right.

 

nipper

I've got a '99 Outback, 2.5 liter. It get driven almost exclusively on country roads, cruising along from 50-60 MPH. Not exactly interstate driving, but definitely not city stop/go either.

 

I get anywhere from 21 (winter) to 26 (summer). IIRC, that range used to be more like 25-29 when the car was new.

 

I own a 98 Legacy Outback, 2.5l, manual. I get pretty much the EXACT same mileage as you. I bought it used, have always gotten the same mileage. Have replaced all the stuff others here have suggested already for you, never noticed much of a difference really. I get my best mileage on highway trips going about 50 to 65mph. Anything over 70 and I dip into the low 20s again. Winter is tough, sometimes only 20mpg in the city.

1996 obw 2.2l 5spd 117k getting 21-22mpg. I just changed my plugs and wires, so I am hoping for a couple more on this tank. I drive faster now that it runs better. I am going to try and lighten up my foot. Basically this tank is going to be inconclusive since I changed my driving habits(unless the mpgs go up:eek: )