Jump to content
Ultimate Subaru Message Board

Announcements


Obscene Mileage for my 2.2


Recommended Posts

Hi all,

I've recently been running Shell Techron 91 octane in my 99 Lego...which has a Phase II 2.2 litre motor with around 142 horsepower running totally stock. I initially made the switch due to the nasty smells that would eminate from my exaust when I rolled up to stop lights, was just sitting at idle, or under quick acceleration. I did this because I recalled when my mothers Audi 100 would make the same odor but stopped when we started to put premium fuel into the tank. Premium definately eliminated the smells entirely from my lego as well but it also put a bit more bang into the block....especially off the line. But what I was most suprised about was when I went to fill the tank while on a road trip to Colorado for thanksgiving. I was driving with a full load of ski, camping, and hiking gear as well as a 30 lb turkey, a ton of beer, and a passenger. We had traveled 275 miles on exactly 7 gallons of 91 octane. That works out to be a little over 39 miles per gallon. We were traveling between 75 mph and 95 mph the entire time with minimal shifts.

 

Has anyone else experienced mileage like this before with their 2.2? If so please share.

Link to comment
Share on other sites

  • Replies 60
  • Created
  • Last Reply

Top Posters In This Topic

That doesn't sound possible. My 2.2 legacy gets 22 mpg constantly in a mixed highway, city driving. On the highway it gets between 28-31 and that's cruising at about 70-80. Plus, I never really have any load in my car. Mainly just me and my empty car. I get about 270 miles on 12 gallons.

Link to comment
Share on other sites

Results may vary. While this may sound too good to be true there might be a few factors that are giving you a bit better than normal readings. Perhaps the gas pump shut off a bit early or conditions were absolutely perfect. Could have had a great tailwind. Try it over a period of time and see what happens.

Link to comment
Share on other sites

I hate to be the nay-sayer, but...nay.

I don't buy it - nearly 40 MPG at an average speed of 85 MPH?

 

Also, how can you prove that it was exactly 7 gallons? Or that your speedo (and therefore your odo) is correct?

 

40 is somewhat hard to believe. And high-octane fuel shouldn't have a performance-boosting effect on a naturally aspirated car.

Link to comment
Share on other sites

Results may vary. While this may sound too good to be true there might be a few factors that are giving you a bit better than normal readings. Perhaps the gas pump shut off a bit early or conditions were absolutely perfect. Could have had a great tailwind. Try it over a period of time and see what happens.

 

Word. I might buy it if it were a 275-mile downhill run with the car in neutral (idling) and no accessories running.

Link to comment
Share on other sites

Do they use imperial gallons in Arizona? I have gotten the occasionally unusual milesage in my car but it was often due to some minor thing like a different pump that shut off early. When I ran a few tankfuls and checked I was pretty much back to normal.

Link to comment
Share on other sites

I think some of the others posting are right, see how your gas mileage averages out over several tanks. Different gas pumps shut off at different times, so if you didn't fill at the same pump twice in a row, that can introduce a lot of variance in what your true gas consumption was. If you can consistently average 39, now that is really pretty nice. -SQ93

Link to comment
Share on other sites

I agree - it takes several "fills" before you can determine a true average fuel consumption number. But the naysayers who claim that different octane ratings on fuel have no difference on mileage need to remember that although these engines are naturally aspirated, the amount of ignition advance (which DOES have a small, but measurable, effect on fuel efficiency) that an engine can tolerate before knocking is dependent on the octane rating of the fuel. So for any car that controls spark advance timing by ECU and tweaks it via input from a knock sensor, using higher octane fuel should show some change in average mileage -- but probably no more than one or two mpg.

Link to comment
Share on other sites

Can I make a guess? This mileage was logged driving West to East?

 

Sort of.....the route I traveled was East on 69 North on I 17 and North on US HWY 89 and then East again on 160 through the four corners and durango to pagosa springs, CO

Link to comment
Share on other sites

tank was probably overfilled at the prior pump, either knowingly or not. no way it's getting 39mpg. even an EJ FWD manual driven at 55 mph in perfect conditions would be hard pressed to get that.

 

 

All gas dispensers are tested once a year for accuracy by standard weights and measures. If you are a beliver or not it really doesn't offend me.

 

Oh and for what it is worth all of the driving took place at an elevation of 5000' or greater. My highest elevation for the trip was probably in Kayenta or maybe Flagstaff both are above 7000'.

 

Be jealous....all of my other buddies who drove their '00 or newer OB wagons out to the cabin sure were.

Link to comment
Share on other sites

report back and let us know what you get. it's not about believing or not believing. it's about the most logical possibility. the most logical explanation is that something was jacked up and the simplest explanation seems to be the gas pump was cut off at different times for the pre and post fill ups. that is much more likely than you having the only bone stock EJ engine in the world that gets 40 mpg at 75mph.

Link to comment
Share on other sites

39 is pretty high...

Once in my 93 leg auto wagon (150,000k ish) I was traveling across Wyoming/Nebraska/Iowa when I achieved 34 mpg at 75 mph. That was running mid grade (since I've noticed in the midwest they tend to lower their octane)

I had a tailwind...no rest area stops... nothin..

That was the best I ever saw..

My avg frwy mileage ran around 28 mpg. in town = 26

Link to comment
Share on other sites

One last thing. Exactly how are you calculating your milage?

 

I've heard some pretty outrageous MPG claims from people and everytime I ask them how they calculate their MPG it's always some crazy way that isn't the least bit acurate. Not saying you are doing it wrong, I'm just curious.

Link to comment
Share on other sites

that it's a manual makes more sense, i was thinking AWD auto but i don't know why. is it FWD or AWD? i'd still be very surprised to see an EJ motor get 40mpg even FWD MT. what are the sticker specifications for this vehicle?

 

a few select older generation soobs are capable of getting 40+ mpg. (88-91 FWD manual XT's and justy's, and probably a few others).

Link to comment
Share on other sites

I agree with most here... however, my 92 Legacy L FWD MT used to get ~32 mpg with highway driving. Kept car well tuned, no aggressive driving, etc. When I would drive at higher elevations I always got better mileage-- colder air maybe? Even then the most I would get is ~34mpg.

 

In my experience though, as others have stated is important, those numbers were consistent over 40-50 tanks of gas. I didn't just get those numbers for a tank here and there-- I recorded every single fill up and averaged them at the end of the year.

 

Nevertheless, you very well could have gotten ~39mpg for that one tank, but take it for an anomaly-- not something to be depended on.

 

Fill up 3-4 times more times, and add total miles traveled over all tanks, including your 275 mile 7 gallon trip, and then divide by the total gallons used over all tanks for those miles, plus your 7 gallons from your trip.

 

After that tell us what your numbers are, and most here will be more apt to give credence to the results.

 

Even if you do a full tune-up, or anything else in there, over 3-5 tanks of gas you are going to see numbers that are more reflective of oem specs and/or general user experience.

 

But, I would be excited about a higher than normal mileage out of a tank of gas too. :)

Link to comment
Share on other sites

but I think I got 31 MPG in my 98 impreza L 4EAT with a 2.2 going to and from Reno.....

 

 

I tracked the gas mileage on my '95 5spd AWD for about a year and I came up with 28-31 when driving mostly in the country (50-60, rolling hills) and 24-27 in the city. The mpg was consistent enough that I stopped bothering to check it (varied only by my driving).

 

Having the tires +2psi from stock definitely helped a mpg or two.

Link to comment
Share on other sites

One last thing. Exactly how are you calculating your milage?

 

I've heard some pretty outrageous MPG claims from people and everytime I ask them how they calculate their MPG it's always some crazy way that isn't the least bit acurate. Not saying you are doing it wrong, I'm just curious.

 

 

Step one at fill up reset trip clock

Step two drive until satisfied

Step three at next fill up record amount of fuel pumped into tank

Step four divide number miles on trip clock by number of gallons pumped into tank.

 

 

I did in fact graduate high school.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...