Forester Mileage Drop

I bought a new 2006 Subaru Forester. It's been a great car and was getting great mileage: 23 city, 27-28 highway, 24-25 mixed.

At 3,500 miles I took it to the dealer for an oil change. Since then, my mileage has has dropped to about 18-19 city, 22-23 highway, and 20 mixed. Any thoughts on what might have caused such a severe drop?

My driving conditions haven't changed, and I've tried switching gas, without any change.

Reply to
russell
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I assume you are really checking mileage using the miles driven/gallons to refill tank? Do you live in an area where they have switched over to fall/winter gas? Does the engine run & idle as smooth as it always did or has the engine performance changed? Maybe there is a vacuum hose loose. Was the battery disconnected for any reason that would result in the ECU resetting to the default value. If the ECU was reset then it will take several tanks of gas for the computer to relearn your easy driving style. Let us know what you discover

Reply to
Edward Hayes

Did you perhaps install a roof/ski rack?

Reply to
Kurt Krueger

Perhaps if the dealer neglected to fill the new filter with oil before installing it, the noises caused by running the engine "dry" for a few seconds caused the ECU to retard the timing.

MV

Reply to
mylesv

Are your Forester's tire pressures the same as the were before?

Reply to
Ron N.

I'd be interested to know if you ever figured it out and how to fix it. Your current milage sounds exactly what wife's Forester gives her. Except that it was never different - we picked the car new and were disappointed with the milage from the start, ~ 20 mixed.

I tried complaining to the dealer and make them investigate but they plainly refused to do anything at all claiming this is perfectly normal milage and "all Foresters are like that".

DK

Reply to
DK

I drive a 2000 Forester S with a 4EAT transmission. I am an easy driver and consistently get 23.5 mpg in my local suburban driving and

26-28 mpg on cruise @ 72 mph (level expressway here in FL.)
Reply to
Edward Hayes

Yeah, I had expected something in this range but it never materialized. We have 2002 Forester with a manual transmission. Never got much above 23 mpg on highway. My wife's driving is very easy and steady, I can't blame the milage on it.

DK

Reply to
DK

I have a 2005 Forester 2.5 X, manual. I get 27+ MPG for my typical, daily driving (range from 26 to 29 from tank to tank). This is mostly country roads with some highway and little city. With strictly highway driving, I have gotten better then 30 MPG (32 MPG on one trip).

Reply to
Steve

How many miles are on your '06? The engines take anywhere from 10-15k to fully break in, so there's going to be variation in mileage up to that point. I'm currently getting 18-20 mpg city and I got 28 on a freeway trip up to Whistler last month (I'm in Seattle).

The comment about winter gas is also worth looking into...

Jesse

Reply to
TeleScooby

I wonder when mine will break in. My 2005 Forester XS manual got 28 mpg new, and now at 30,000 miles still gets 28 mpg. This mostly highway at 70 mph. I have gotten as much as 30 mpg, and lowest 25 mpg, but I never drive in a city for very long.

EPA claims 23-30 mpg so I have been pleased with my results.

I keep hearing these break in stories, but of the 5 new vehicles I have owned, I have never gotten a variation due to how many miles on one. Of course I have never went more than 70,000 miles on any of my vehicles.

Blair

Reply to
Blair Baucom

I'm sort of anal about keeping track of my mileage. Something I picked up from my father. I reset my odometer with every tank of gas and keep a record in my glove box with gallons and miles driven per tank.

Engine idles fine, like always. Battery hasn't been disconnected to my knowledge. The only time it's been out of my car was at the dealership, and the clock and radio still had my settings after I got the car back, so I can't imagine they disconnected it.

I don't know about the gas. I will have to check up on that. I've put in 5 tanks since the mileage drop, with no difference in my mileage. I usually use the Shell Plus from one particular station, but have also tied Shell Plus from a different station, and some other brands, without any differences.

Reply to
russell

I'm sort of anal about keeping track of my mileage. Something I picked up from my father. I reset my odometer with every tank of gas and keep a record in my glove box with gallons and miles driven per tank.

Engine idles fine, like always. Battery hasn't been disconnected to my knowledge. The only time it's been out of my car was at the dealership, and the clock and radio still had my settings after I got the car back, so I can't imagine they disconnected it.

I don't know about the gas. I will have to check up on that. I've put in 5 tanks since the mileage drop, with no difference in my mileage. I usually use the Shell Plus from one particular station, but have also tied Shell Plus from a different station, and some other brands, without any differences.

Reply to
russell

I have an aftermarker Thule bike rack, but it's been on the car since I bought it, so that can't be it. I've also very recently added mud flaps, but that was after the mileage drop and hasn't seemed to affect the mileage since. No physical alterations were made to the vehicle that coincide with the timing of the mileage drop.

Reply to
russell

That was the first thing I checked. The pressures are all standard, according to the manual.

Reply to
russell

I've heard about the break in period, but I was under the impression that new cars get better mileage as the engine starts to wear a bit, not worse. Most people seem to be getting very good mileage with their Foresters, on par with what I was originally seeing when I bought the car new.

The car now has 4,500 miles on it. Probably 75 percent highway, 25 percent city.

Reply to
russell

A little late to the discussion, but a faulty coolant temperature sensor will cause most vehicles (and I assume, Subbies) to think that the engine hasn't warmed up yet, and run rich all the time. It won't set any trouble codes either.

Reply to
Ken Finney

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