Ok, I consistently get 32 mpg hwy in my EJ25 Legacy. However, this trip I got 27, the vehicles EPA rating. This was the first official calculation I had done with my weapon-R short ram. I had switched from a K & N Panel filter.

Now here's the difference. I filled up with 89 octane rather than 87. The EJ25 debuted in 1996 and required 89 or higher. That changed in '97. But I figured I would give my Legacy some of the good stuff. Do you think it was the octane that made the difference? A nasty head wind, that I didnt notice? Or does anyone's gas mileage suffer when they go higher than 80 mph?

 

I really do think that it was the change in octane, but Im lookin for ideas that I hadnt thought of.

Ok, I consistently get 32 mpg hwy in my EJ25 Legacy. However, this trip I got 27, the vehicles EPA rating. This was the first official calculation I had done with my weapon-R short ram. I had switched from a K & N Panel filter.

Now here's the difference. I filled up with 89 octane rather than 87. The EJ25 debuted in 1996 and required 89 or higher. That changed in '97. But I figured I would give my Legacy some of the good stuff. Do you think it was the octane that made the difference? A nasty head wind, that I didnt notice? Or does anyone's gas mileage suffer when they go higher than 80 mph?

 

I really do think that it was the change in octane, but Im lookin for ideas that I hadnt thought of.

 

Winter fuel, tired o2 sensor. Gas Mileage doesnt really count untill you have 3 tanks of gas recorded.

 

nipper

Winter fuel, tired o2 sensor. Gas Mileage doesnt really count untill you have 3 tanks of gas recorded.

 

nipper

 

I agree, however I make the drive from home to Penn State pretty often and always get 32 mpg. So winter fuel doesnt add up entirely. O2 senor might.

do you always drive over 80 mph?? i find it hard to believe you get 32 mpg @ 80mph.

I notice that you said this was your first calculation with a new intake on. I wonder if you were craving the sound of an open intake a little and stepping into the loud pedal more than you normally would have? or maybe the ecu is learning the new ammount of airflow and over-fueling?

I just did a run in our MY02 OBW from Delaware to Ohio via the PA turnpike.

 

The way out I cruised at 80+ MPH with the RPMs at 3000-3200 and got 24 MPG.

On the way back I slowed it down to 70-75 with the RPMs at 2600-2800 and shot up to 28 MPG, it took me and hour longer to get home.

I notice that you said this was your first calculation with a new intake on. I wonder if you were craving the sound of an open intake a little and stepping into the loud pedal more than you normally would have? or maybe the ecu is learning the new ammount of airflow and over-fueling?

 

Very good point. I do enjoy hearing it, but I usually save it for the curvey roads.

Ive had the intake on for a while, and have never calculated it before, but this was the worst hwy mileage I have ever gotten with it. I know this because my trip required an extra gallon and a half of fuel.