The MPG Challange

Hello everyone,

 

So recently I bought my Legacy 2.5i Automatic and I have been driving it around the city and I get 21.0 mpg to show up as my average mpg on the display. So recently, I have been trying to think of ways to improve my mpg by driving better. I tried to be a little bit more careful with how much and often I keep my foot on the gas.

 

1) I tried to let go off the gas when I drove downhill and sort of let the car slide.

2) I accelerated very slowly going from 0 to about 40 during city driving. Sometimes when the road was long and open, I even put the cruise control in at around 35 or 37.

 

3) letting go off the gas earlier when I see the red light ahead

4) And recently I also tried to lower my top speed by always driving the speed limit or about 3-5 mph below (I noticed that due to the red lights, I still get there just as fast as the other guys who speed like maniacs).

 

Just off number 1 and 2, my average mpg went up to 21.3. I threw in number 3 and 4 and this morning when I checked my display it said I am now up to 21.6 mpg.

GREAT SUCCESS!.

 

This great success has motivated me to thow up a mpg challange to anyone who wants to participate. My next goal is 22.0 mpg during all city driving (no highway at all).

 

Anyone who is interested in improving mpg can post their current miles per gallon and progress across time. If anyone finds any good products or upgrades that assist with mpg, feel free to past that here is well.

 

I will update you guys when I hit 22.0 mpg. I want to see how far I can take this success

 

Anyone in?

i have a GT and i dont have a digital display like you guys, i just have that stupid needle, but im at about 160 miles just under half a tank idk if you could figure out how many MPG that is. . .

How to calculate your MPG

1. Go to the gas station and fill up the fuel tank.
   
2. Record the mileage, before even pulling away from the pump. We will call this Mileage A.
   
3. Drive normally until the tank is less than half full.
   
4. Fill up the tank again (preferably at the same station using the same pump as pumps may be calibrated differently). This time, pay attention to how many gallons it takes to fill up the tank. This is usually shown at the pump.
   
5. Record the mileage again, just like before. We will call this Mileage B.
   
6. Subtract Mileage A from Mileage B. This will give you the number of miles you drove since your last fill-up.
   
7. Divide your answer by the number of gallons it took to fill up your tank. This will give you your car's MPG.

Found this on Howwiki or whatever that website is called.

How to calculate your MPG

1. Go to the gas station and fill up the fuel tank.
   
2. Record the mileage, before even pulling away from the pump. We will call this Mileage A.
   
3. Drive normally until the tank is less than half full.
   
4. Fill up the tank again (preferably at the same station using the same pump as pumps may be calibrated differently). This time, pay attention to how many gallons it takes to fill up the tank. This is usually shown at the pump.
   
5. Record the mileage again, just like before. We will call this Mileage B.
   
6. Subtract Mileage A from Mileage B. This will give you the number of miles you drove since your last fill-up.
   
7. Divide your answer by the number of gallons it took to fill up your tank. This will give you your car's MPG.

Found this on Howwiki or whatever that website is called.

 

or use one of the trip odometers instead of subtracting A from B. Just make sure you restart it when you fill up. Then at your next fill up, divide the trip odometer number by the number of gallons you put in...rinse and repeat ;-)

i dont know how you manage to drive at only 21mpg. personally i avg 19-22 when i have a lead foot. and when i drive very conservatively i avg 25-29mpg.

 

 

 

edit: drive more conservatively than what you consider conservative.

well 2 reasons I can think of why I am only getting 21 mpg.

 

1) my car is automatic transmission not manual

 

2) I drive 100% city 0 percent highway right now (will change in a month though)

 

3) So far been reading off the display - not sure if display is accurate

 

and besides that Subaru lists the mpg at around 21 or 22 on their website so I thought I was average. Not sure how you would squeeze out 25-29 unless you drive highway a bit

 

and ummm...what do you consider more conservative?

ouch... 100% city driving.

 

not sure how this would apply in the a/t but its worth recommending..

 

stay under 3k rpm. see if that makes a difference. last time i did that, i avg 23-24 city. minimal hwy.

I average about 26.9, and at my best I was at 28. Thats mostly highway at 65-70mph.

How many miles on this car? I think if you are under 5k your mileage will be lower. I definitely noticed the car got better with mileage as it broke in.

^ Theres your answer.

 

No car gets optimal mileage while its in the break in period.

 

 

And in case you were wondering, I was getting 31 miles to the gallon on my 250 mile trip to VA beach this weekend, with A/C, 55 MPH, and many a stoplight. I don't know how they do it!

The mpg display is not accurate. Another member posted a chart showing actual compared to display and the results were erradic.

Hello everyone,

 

So recently I bought my Legacy 2.5i Automatic and I have been driving it around the city and I get 21.0 mpg to show up as my average mpg on the display. So recently, I have been trying to think of ways to improve my mpg by driving better. I tried to be a little bit more careful with how much and often I keep my foot on the gas.

 

1) I tried to let go off the gas when I drove downhill and sort of let the car slide.

2) I accelerated very slowly going from 0 to about 40 during city driving. Sometimes when the road was long and open, I even put the cruise control in at around 35 or 37.

 

3) letting go off the gas earlier when I see the red light ahead

4) And recently I also tried to lower my top speed by always driving the speed limit or about 3-5 mph below (I noticed that due to the red lights, I still get there just as fast as the other guys who speed like maniacs).

 

Just off number 1 and 2, my average mpg went up to 21.3. I threw in number 3 and 4 and this morning when I checked my display it said I am now up to 21.6 mpg.

GREAT SUCCESS!.

 

This great success has motivated me to thow up a mpg challange to anyone who wants to participate. My next goal is 22.0 mpg during all city driving (no highway at all).

 

Anyone who is interested in improving mpg can post their current miles per gallon and progress across time. If anyone finds any good products or upgrades that assist with mpg, feel free to past that here is well.

 

I will update you guys when I hit 22.0 mpg. I want to see how far I can take this success

 

Anyone in?

 

how you only gettint 21mpg. i have a lgt with a 5mt and i do some spirited driving and get like 23-24. ive gotten 30mpg. my charger r/t get 25 on the highway.

Come on guys, rolling in my OBXT, Stage 1 93oct maps i can push 26.1mpg

i've got pics to prove it too! i think i did 407 miles on the tank, had a good 1/2 gallon or more left to go when i filled up.

my car only has 5000 miles on it. I guess that is part of it. Still not even fully broken in yet

The mpg display is not accurate. Another member posted a chart showing actual compared to display and the results were erradic.

 

were the actual results better or worse than the display results?

my car only has 5000 miles on it. I guess that is part of it. Still not even fully broken in yet

 

Yep and 21 mpg is about right for an automatic 2.5i. I think once you start driving highway, you will be really impressed. It shouldnt be a problem for you to hit above 30 mpg hwy driving, assuming you cruise at 75 mph or below.

 

An aftermarket air filter or intake cone can also boost mpg 1-2. I spent $70 on an intake and went from 29 mpg to my record 33 mpg. Its already paid for itself.

90 % highway 10% city tonight after refueling, averaged 8litres/100km....around 27-29mph going 65....letting go of the gas for red lights and staying in neutral when possible, using 4th gear at 37-40miles per hour in my LGT ....catless turboback, perrin pulley and short ram

I did a small personal study on my driving habits; driving conservatively but keeping up with traffic gives me ~25-27 mpg, 90/10 split city/highway.

 

On this tank, I'm going WOT from the stoplights, and it's showing up as 22.8 mpg. Car has 34111 miles, which may make a difference. I used to get 17-19 mpg when the car was still under 10k miles.

I average 24 mpg in mixed city and freeway driving in my Outback 2.5i 4AT. I can get 30 mpg in pure freeway driving with a light foot. The funny thing is that since my OB is so slow compared to my LGT that I consciously try to drive slow and maximize mileage since that constitutes "performance" for the little n/a motor

were the actual results better or worse than the display results?

 

The actual miles are worse. The service manager explained that the computer is calculating an average based on pedal habit. If that is the case, idle is not calculated. You also need to keep in mind the effects of ethanol in the gasoline. You can lose 10% mpg just because ethanol is added to the gasoline. Other members have posted on this matter, so just do a search.

The service manager is wrong. The computer calculates mileage based on injector duty cycle. It should be accurate, but it's not.

The service manager is wrong. The computer calculates mileage based on injector duty cycle. It should be accurate, but it's not.

 

He drives a Viper and used to work for Toyota...(insert comment here). Thanks for the info.

The service manager is wrong. The computer calculates mileage based on injector duty cycle. It should be accurate, but it's not.

I go with the computer because I trust the car know how much fuel it is burning better than the accuracy of a crappy gas pump. Then their is the fact that the accuracy of gas pumps is way off in areas that have dramatic seasonal temperature differences like us in the midwest. We get less fuel per dollar in the summer than in the winter becasue gasoline expands when it is warmer.

Fact is, the computer is close enough, and probably better than calculating it yourself. Maths is hard.

 

I do notice that the computer in my old VW Passat seemed a lot more accurate than the one in the Sube. The Sube one doesn't seem to calculate as often. The VW trip computer would start computing instantly while the Sube waits to start until you have 1 mile on the car. Also the Sube trip doesn't update the mileage as often, in the VW if you mileage dropped by .1 mpg the display would show that instantly.

As of now with 4000 miles on my 2.5i, my gauge reads an average of 24.9. Not bad.

You shouldn't be coasting downhill. You should be easing off the gas uphill and pushing the pedal more downhill.