Brand new 2013 WRX and MPG problem

**Mo Rex** · 12-22-2012 05:39 PM

Hey guys, I'm a happy new owner of a 2013 hatch but I'm running into a problem. My first gas tank got around 20 mpg ( total miles divide by how many gallons I filled up). That's fine but I filled up last night and drove only 45 miles all day and the tank shows less than 3/4 tank now. I drove conservative (shifting btwn 2500-3000) and the dashboard says I'm averaging about 22.3 mpg. I don't know what I'm doing wrong. I'm taking the same route to work I did all week. Any ideas of what can be causing this?

Thanks,

Mo

**WREXXY** · 12-22-2012 06:19 PM

is your drive all highway? or is it city type driving? is it hilly? how long is your commute (does the engine ever get up to temp)?

how do you accelerate? even if you shift at 2.5k-3k, if you go 1/2 throttle your guna lower your mpg.

Also, it's winter time so the winter grade gasoline is being sold, although it is cheaper (thankfully) it does reduce your fuel economy (i don't know to what extent).

I'm at 1000 miles now on my '13 hatch that i got 2 weeks ago and I've been averaging around 25.5mpg (miles drive/gallons filled up method) and any where from 25.8-26.4 (on the car average mpg).

I drive 90% highway at 65 mph usually (hit some traffic in certain spots), if i'm going for mpg i shift at or before 2.5k and accelerate smoothly (albeit, I guess it is rather slow sometimes). 5th gear at 45 mph and up seems to produce good fuel economy.

I'll do some 2nd-3rd gear pulls once in awhile, cause i didn't buy the car for fuel economy, but i still average about 25.5mpg

**WREXXY** · 12-22-2012 06:23 PM

i have noticed that each notch on the fuel gauge equates to around ~35 miles that's just a rough estimate based on what i've observed. usually at half a tank i'm around 170-180 miles, but i've only filled up 4 times so far

**Mo Rex** · 12-22-2012 06:55 PM

My drive is approx 17 miles each way. half hwy and half on local streets. The street are level but doesn't matter because I take the same route everyday. I accelerate slowly not slamming on the gas at all. Because I had a full tank I was driving it conservatively to see how much mpg I would get but the opposite result happened. 45 miles traveled and more than 1/4 of my tank is gone. I have less than 300 miles on the car the only change that I have done was the tires. Conti DWS 235/45/17 same size as oem and those tires were on the car for majority of the first tank of gas. I am still riddled.

**Mo Rex** · 12-22-2012 06:59 PM

If what you are saying about each notch equaling 35 miles then I should still have more than 3/4 tank. Or at least 3/4's. I'm using 93 octane from a Hess station around the block. Maybe ill try Sunoco or BP gas. But can the name brand of gasoline be that different?

**rockstar4l** · 12-22-2012 07:06 PM

I've had my wrx for 3400 miles now. I've never reset my second trip odometer and it says I've gotten 19.8 mpg so far for the life of the car. I do drive spirited I live in the back roads and probably do about 30% of my driving on the highway so of course I am a little low on mpg. But I wouldn't expect great mpg, hope this helps

**WREXXY** · 12-22-2012 07:28 PM

I use BP 93 octane, mostly because it's right by where i work and the fact that it's 15+ cents cheaper than anywhere else i've seen doesn't hurt. Don't know if brand matters, maybe try sunoco? Isn't that the brand nascar uses?

And as far as the whole notch thing = 35, that was a REAL rough estimate and based on however I was driving at the time. It's more realistically around 30 or so

**rurso01** · 12-23-2012 11:49 AM

I doubt this is your issue, but I noticed it definitely had me scratching my head.. I park on a sloped driveway and knew I didn't have a full tank of gas but because of the slope, it read a full tank for a good 15 miles before it started dropping (and fast) to its accurate level. My former WRX and other cars never took that long to register accurate or even get effected by the slope so maybe thats a possibility? just throwing out ideas.

**Mo Rex** · 12-23-2012 12:09 PM

Thanks for the replies guys, the only explanation is that the gas stopped pumping before it was full and didn't notice if the guage actually went to Full. I only noticed the issue when I came home from work. From about 1/4 tank left I filled up 11.7 gallons. What is the capacity of our tanks not including emergency tank?

**rurso01** · 12-23-2012 12:17 PM

Originally Posted by Mo Rex

Thanks for the replies guys, the only explanation is that the gas stopped pumping before it was full and didn't notice if the guage actually went to Full. I only noticed the issue when I came home from work. From about 1/4 tank left I filled up 11.7 gallons. What is the capacity of our tanks not including emergency tank?

16.9 Gallons

**matsayz** · 12-23-2012 12:29 PM

Rex, how many miles do you have on your car? Until you get used to driving the car the mpg's will vary. Having a heavy right foot doesn't help as well. Also remember that everyone is on winter gas. I'm tuned but I get around 75miles per quarter of the gas gauge.

There are plenty of plenty of threads on this site about mpg's. I suggest reading through those and checking it out. If all else fails goto your local stealership.

**starkall** · 12-23-2012 12:49 PM

If you live in a cold climate the winter mpg is significantly lower. My 13 sti has about 2500 miles on it. In the warmer weather I'd average about 24mpg. Now in the cold I average about 17mpg.

**starkall** · 12-23-2012 12:51 PM

Plus the winter blend fuels will affect it.

**matsayz** · 12-23-2012 03:28 PM

Rex, how many miles do you have on your car? Until you get used to driving the car the mpg's will vary. Having a heavy right foot doesn't help as well. Also remember that everyone is on winter gas. I'm tuned but I get around 75miles per quarter of the gas gauge.

There are plenty of plenty of threads on this site about mpg's. I suggest reading through those and checking it out. If all else fails goto your local stealership.