Subaru Forester Gas Mileage

13 comments ↓

#1 Steve Abell on 12.14.07 at 2:10 pm

I have about 1500 miles on a new ‘08 2.5X auto trans. My gas mileage is way below the rating, esp on the highway (I’m getting 21-22 mpg, same as around town). The local Subaru service guy tells me that in cold weather (I live in Iowa) the extra drag of the AWD cuts into mileage, and I shouldn’t expect to see good highway mileage until summer. Does this make sense? I got better highway mileage on my old 3.5L V6 Intrepid.

#2 mpg-o-editor on 12.14.07 at 3:37 pm

Your service guy might not be far off the mark, Steve … but I’m wondering why your getting the same mileage in town that you are on the highway.

The highway rating for the Forester 2.5X is 26 miles per gallon. A 20% hit, considering winter temps, AWD usage, and the break-in period isn’t all that outrageous.

Winter presents a bit of a catch 22 … engines run most efficiently once they’ve warmed up to operating temperature … but that warm-up time cuts into the gas mileage.

I’m a big fan of synthetic oil … it costs significantly more than conventional oil, but it offers a much greater level of protection and allows an engine to operate at peak efficiency.

#3 Steve Abell on 12.14.07 at 6:09 pm

OK, thanx. Maybe my expectations were a bit optimistic, and I really haven’t driven the car all that much. I was so careful to follow the instructions for break-in. I was thinnking maybe the computer that controls the engine operation might need some attention. My son bought a Ford truck, and got terrible highway mileage until he took it into the Ford shop and they “reprogrammed” (whatever that really means) the engine computer. Whatever they did, his mileage got significantly better. Any chance that’s what’s going on with my Forester? All the other aspects of the vehicle have been great - I really like it. Just hope the highway mileage improves with time. Thanks again. I may give the synthetic oil a shot.

#4 kukla on 01.08.08 at 4:33 pm

let me know if that reprogramming works - i have the same problem (avg 15-17 mpg) on 2003 Forester XS A.T.) 98% city driving (so. calif) - only 31K miles on the car. could that be it? stop and go….

#5 martin on 01.10.08 at 3:57 pm

For reference, my 2001 Subaru Forester Manual has averaged 24.5MPG todate(7+years). This is town, highway & mountain average in Oregon.
As you know, expect poorer mileage with fuel containing alcohol. Any alcohol gives you 30% less mpg than gasoline.

#6 KMJ on 01.25.08 at 8:12 pm

Well, I just upgraded & downgraded at the same time…got a little cushier 2003xs w/sr for my 2005 forester x (the 2003 had 14000 less miles on it, 34000). In the 2005x manual I was getting consistently 29/30/mpg now, I am getting 25mpg. needless to say I am disappointed that a change in cushiness brought on a change in gas mileage to such a degree. I am really a gas watcher. Yes, it’s cold, but I am disappointed despite the superb ride I get.

#7 Steve on 02.01.08 at 3:55 pm

Martin, I agree with your mileage number on alcohol. Here are some more numbers, so see if you agree:

The ethanol/gas mixture I usually buy here in Iowa is 10% ethanol (known as E10). So for every ten gallon fill-up, I’m really getting nine gallons of gas plus one gallon of ethanol. The ethanol only gives me 70% of the gas mileage of regular unleaded, so ten gallons of E10 is worth (theoretically, in terms of gas mileage) 9.7 gallons of straight gasoline. In other words, I should be able to travel the same distance on either 10 gallons of E10 or 9.7 gallons of straight gas. On a gas mileage basis, E10 is giving me 0.3/9.7 = 3.1% less gas mileage. Then, all else being equal, if I get 20 mpg on straight gas, I should get 19.4 mpg if I burn E10.

The cost situation is a little brighter. Today, here in Iowa, E10 is selling for $2.86 per gallon, regular gas is ten cents higher, at $2.96 per gallon. I would pay $28.60 for the ten gallons of E10 and $28.71 for the 9.7 gallons of straight gas. So E10 is a slightly better deal in terms of gas cost per mile than straight gas, even though the mpg is lower.

I think the mileage on my Forester is getting a little better, although with cold starts twice a day going to and from work, it’s a little hard to tell. I’ll have to check on my next major road trip. I really like the car, and enjoy driving it. The AWD has been surefooted on slippery roads as long as I don’t get too overconfident and careless.

One more thing, my local Subaru service guy says there’s no way for him to re-program anything. When I asked him about my son’s experience with his truck, he gave me a funny look. So I guess I’ll just enjoy driving the Forester and stop worrying about mileage.

Happy trails…..

#8 Todd Beery on 02.05.08 at 5:12 pm

After a lot of research I have found that the foresters o2 sensors need to be monitored from time to time. There are 2 one before the catalytic converter & one after. If these go bad gas mileage drops considerably. There is also a 2 in 1 chip that sells on ebay that has good reviews. It will increase mileage about 8mpg & is simple to install. It makes sure that the gas air mix is perfect, hence more efficient burning & better mpg. Just do a search for the 2 in 1 chip for the forester.

#9 Steve on 02.08.08 at 3:40 pm

Todd, I found the Dynamic Tuning 2-in-1 chip on eBay, just as you suggested. Please don’t be offended by this next question: are these guys on the up-and-up?

I’m old enough to have learned the hard way that when something sounds too good to be true, it probably isn’t. If I understand the benefits of the chip presented in the eBay ad, I can get 30-40% better gas mileage both around town and on the highway, and more horsepower, from a $16 (incl shipping & handling) investment. Forgive me, but that sounds too good to be true. One other thing troubles me: shouldn’t a chip like this be selected based on the engine in the car, rather than the car model? Foresters come in a couple of engine selections, but the chip works in a 4 and a 6 cylinder equally well? That just doesn’t sound right to me.

I very much appreciate you taking the time to post the suggestion. Help me a little to understand that this chip is really going to work and not do some unintended damage. I’m not hesitant to order one, the investment is small. My real concern is that it might screw up my Forester’s computer system, or make the car hard to start, or greatly increase emissions, or something else. In the FAQ on the Dynamic Tuning site there’s a claim that the Subaru warranty will not be voided by installing the chip. True? It just seems that there must be some downside to doing this. Can I impose on you to help me get more comfortable with this before i install a chip? Thanks.
Steve

#10 Steve on 02.08.08 at 3:50 pm

Oops, I think I misspoke. All ‘08 Foresters come with a flat 4 Boxer engine, don’t they? Some are turbo, some not, but maybe that’s not issue. Apologies to the Forester faithful out there.
Steve

#11 kukla on 03.26.08 at 11:15 am

does anyone have directions as to how to remove headliner and panels from 2003 forester so as to service the moonroof. either the window is off track or something is jammed. thanks. kukla.

#12 rebecca on 05.05.08 at 12:53 am

I am looking into buying a forester (probably not new) what is your perception on the best years and models for reliablilty and gas mileage?

#13 Ann on 07.13.08 at 5:09 pm

I have a 2002 forester which I am trading in. What is you opinion on purchasing a 2008 used Forester vs a new 2008 Outback. I loved my forester but am wondering the difference with gas mileage between the two. I do like sitting up high in forester ? Buying a car is no easy thing to do.

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