Old member, new car(Subaru), bad mpg's
 

Well I sold my VX for something a little more winter friendly, and good thing as we had our first snow this morning. Not a good snow, but the road was slick enough going through one of the mountains. Well I got a 97 Subaru Impreza Outback wagon, it is "rated" at 29mpg, which I was desperately hoping to achieve, but after driving it about 3 weeks now, I can say the best I've gotten is 26mpg with all highway, but an average of only 23-25. I pumped the tires up, tuned it up, and still have yet to hit 29mpg. I know what kills some of my mpg is going up and down 2 mountains, twice a day, making for 4 pretty substantial "climbs" and obviously 4 decents(neutral, of course). I try to limit my speed and rpm's when going up, but other than that i'm at a loss as to why I can't hit at least the EPA rated goal. I was wondering if anyone has a recomendation for a MPG monitor? Its OBD2 so that has to help simplify it, I just don't know which to buy or from where. Also curious if anybody has had any experience with a similar car and can share there mpg's.. i hope i'm not the only one with this kind of bad mileage from these cars. I had a Yukon a few years back that I was able to get within 6-7mpg of what I'm getting from this car that is half it's size

Since the vehicle is a '97, a SG2 would be a choice for an mpg monitor. www.scanguage.com You can check for and clear trouble codes, monitor coolant and battery voltage, and several other parameters. Welcome to the site!

A few thoughts...

Old EPA vs. new EPA. If you look it up now on the EPA site you will get the "revised" numbers. The older numbers were harder to achieve. https://www.fueleconomy.gov/feg/bymod...emodelNF.shtml

Maintenance items. Transmission fluid or lube changed? Oil changed, replaced with your preferred thinnest allowed oil? check the manual, if it offers your choice of several weights use the thinnest offered unless you have leak problems. Air filter changed? Differential/4wd lube changed? Not sure if that's the same as the tranny fluid or not on a Subaru.

Previous owners/mechanics might have had different ideas about lube, or maybe neglected that maintenance completely.

Marginally bad oxygen sensor? Should be pretty quick for a shop to check it with a voltmeter, or you can do it if you look up the how-to.

20/27 manual ... 21/28 auto ... so you are within 1 or 2 highway and doing about right if they had a "combined" mpg

Cold weather...short trips...hills...all going to affect mpg

A grill block or block heater would probably go along way to up that mileage

yeah i checked that site out, 28 i guess doesn't make me feel so bad, but on my 120 mile round trip commute(sometimes upwards of 200, blah) i wish i could get more like 28+ mpg. i'm debating a grille block, i just don't know how to secure the board to the grille, and i don't want to overheat so i guess it would take some experimenting

Its winter, so you shouldn't worry about overheating, and if you get the scanguage, you can monitor the temperatures.

I used zipties and electrical tape for my grill blocks...electrical tape is holding a lot better than I thought

I use zip ties. I use the little tiny ones, like 1/16" across. 3 of them on each plate behind my grill (so their actually in tension doing something too, not compression aka just pushed against the grill) so they'll hold.

What to make it out of: coroplast (political campaign sign material), cardboard, I have a couple aluminum plates that fit beautifully that I found in my garage.

in my experience (going 75-80 mph on I-80 through the Appellations) mountains have helped mileage, but that was also interstate so the grades are pretty tame (2 different cars, both directions, 3 tanks of gas each, 3 times) My theory is at least at that grade and speed, you save more gas going down than you use over normal going up...at that grade and speed. Either that or it's the Amish that live in that area.

I think it's the Amish. They're quite thrifty.

As mentioned put some new lube in the tranny and rear differential.

Use regular recommended oil in the tranny(shared with front diff) because the synchros don't like synthetic.

However I would suggest putting synthetic in the rear diff.

Also take off the roof rack.

And i would suggest replacing the hood with one without a hoodscoop.